Author name code: young ADS astronomy entries on 2022-09-14 author:"Young, Peter R." -aff:"Australia" ------------------------------------------------------------------------ Title: Additions to the Spectrum of Fe IX in the 110-200 Å Region Authors: Ryabtsev, Alexander N.; Kononov, Edward Y.; Young, Peter R. Bibcode: 2022ApJ...936...60R Altcode: 2022arXiv220615354R The spectrum of eight-times ionized iron, Fe IX, was studied in the 110-200 Å region. A low inductance vacuum spark and a 3 m grazing incidence spectrograph were used for the excitation and recording of the spectrum. Previous analyses of Fe IX have been greatly extended and partly revised. The number of known lines in the 3p 53d-3p 54f and 3p 53d-3p 43d 2 transition arrays is extended to 25 and 81, respectively. Most of the identifications of the Fe IX lines from the 3p 53d-3p 43d 2 transition array in the solar spectrum have been confirmed and several new identifications are suggested. Title: Properties of EUV Imaging Spectrometer (EIS) Slot Observations Authors: Young, Peter R.; Ugarte-Urra, Ignacio Bibcode: 2022SoPh..297...87Y Altcode: 2022arXiv220314161Y The Extreme ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft has been operating since 2006, returning high-resolution data in the 170 - 212 and 246 - 292 Å wavelength regions. EIS has four slit options, with the narrow 1'' and 2'' slits used for spectroscopy and the wide 40'' and 266'' slits used for monochromatic imaging. In this article several properties of the 40'' slit (or slot) are measured using the Fe XII 195.12 Å line, which is formed at 1.5 MK. The projected width of the slot on the detector shows a small variation along the slit with an average value of 40.949''. The slot image is tilted on the detector and a quadratic formula is provided to describe the tilt. The tilt corresponds to four pixels on the detector and the slot centroid is offset mostly to the right (longer wavelengths) of the 1'' slit by up to four pixels. Measurement of the intensity decrease at the edge of the slot leads to an estimate of the spatial resolution of the images in the x -direction. The resolution varies quadratically along the slot, with a minimum value of 2.9'' close to the detector center. Intensities measured from the slot images are found to be on average 14% higher than those measured from the 1'' slit at the same spatial location. Background subtraction is necessary to derive accurate intensities in quiet-Sun and coronal-hole regions. Prescriptions for deriving accurate slot intensities for different types of slot datasets are presented. Title: Investigating Solar Wind Formation in the Inner Corona Using ADAPT-WSA Authors: Wallace, Samantha; Young, Peter; Arge, Charles; Viall, Nicholeen; Jones, Shaela Bibcode: 2022cosp...44.1321W Altcode: Several fundamental outstanding questions in heliophysics pertain to the genesis and energization of the solar wind - both of which are driven by physical processes that largely occur in the inner solar corona. Recent and upcoming missions enable more direct measurements of the inner corona; however, the use of a model is required to bridge in situ and remote observations to investigate how the solar wind was formed. We present results from aggregate work that support this claim, where we use the Wang-Sheeley-Arge (WSA) model driven by Air Force Data Assimilative Photospheric Flux Transport (ADAPT) time-dependent photospheric field maps to connect in situ solar wind observations from various spacecraft (e.g., PSP, SolO, ACE, Helios) to their source regions at 1 Rs. We show results in which we apply our modeling to test solar wind formation theories (e.g., reconnection/S-web, waves-turbulence, expansion factor), and to characterize the solar wind from specific sources (e.g., active region vs. quiet Sun coronal hole boundaries, deep inside coronal holes). We discuss several current and former collaborations, including connecting PSP in situ measurements to remote composition measurements from Hinode/EIS, and identifying the sources of transient eruptions observed at PSP. We close with how ADAPT-WSA is currently supporting both the PSP and SolO missions. Title: Scattered light in the Hinode/EIS and SDO/AIA instruments measured from the 2012 Venus transit Authors: Young, Peter R.; Viall, Nicholeen M. Bibcode: 2022arXiv220709538Y Altcode: Observations from the 2012 transit of Venus are used to derive empirical formulae for long and short-range scattered light at locations on the solar disk observed by the Hinode Extreme ultraviolet Imaging Spectrometer (EIS) and the Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA) instruments. Long-range scattered light comes from the entire solar disk, while short-range scattered light is considered to come from a region within 50" of the region of interest. The formulae were derived from the Fe XII 195.12 A emission line observed by EIS and the AIA 193 A channel. A study of the weaker Fe XIV 274.20 A line during the transit, and a comparison of scattering in the AIA 193 A and 304 A channels suggests the EIS scattering formula applies to other emission lines in the EIS wavebands. Both formulae should be valid in regions of fairly uniform emission such as coronal holes and quiet Sun, but not faint areas close (around 100") to bright active regions. The formula for EIS is used to estimate the scattered light component of Fe XII 195.12 for seven on-disk coronal holes observed between 2010 and 2018. Scattered light contributions of 56% to 100% are found, suggesting that these features are dominated by scattered light, consistent with earlier work of Wendeln \& Landi. Emission lines from the S X and Si X ions - formed at the same temperature as Fe XII and often used to derive the first ionization potential (FIP) bias from EIS data - are also expected to be dominated by scattered light in coronal holes. Title: Elemental composition diagnostics for Hinode/EIS Authors: Zambrana Prado, Natalia; Buchlin, Eric; Pelouze, Gabriel; Young, Peter Bibcode: 2022cosp...44.2581Z Altcode: In order to explore the connection between the solar atmosphere and the solar wind, it is helpful to look at the elemental abundances for they carry evidence of the origin region of the escaping plasma. This is due to the first ionization potential (FIP) effect which results in an enhancement of the abundances of low FIP elements. To provide composition maps, we developed the Linear Combination Ratio (or LCR) method which allows for relative abundance measurements forgoing the need of differential emission measure inversion. This method has been thoroughly tested on synthetic spectra and on spectroscopic data. The proof of concept for the LCR method was published in Zambrana Prado and Buchlin [2019], in that paper we focused on measuring the FIP bias between sulfur and a mixture of iron and silicon. In this paper we consider the most commonly-used EIS studies and identify element pairs that can be used as diagnostics of the FIP effect. We apply the LCR method and obtain FIP bias measurements in sample datasets. This demonstrates that a large portion of the EIS archive can be used for abundance diagnostics, and the LCR method opens the possibility of deriving abundance ratio maps semi-automatically leading to new data products for the community. We developed the LCR method further by designing a numerical procedure based on a statistical approach and the Bayes theorem to compute uncertainties of these FIP bias diagnostics. It can take into account uncertainties in the atomic physics and in the instrument calibration. It provides the probability distribution of the real FIP bias of the plasma given the measurement provided by the LCR method. Hinode has been coordinating with other resources such as ALMA, PSP, Solar Orbiter, and DKIST, just to name a few. These new diagnostics come as an add-on to our tool-belt, opening the possibility to see through an additional perspective over a decade and a half of coronal spectra. Title: Abundance diagnostics in active regions with Solar Orbiter/SPICE Authors: Giunta, Alessandra; Peter, Hardi; Parenti, Susanna; Buchlin, Eric; Thompson, William; Auchere, Frederic; Kucera, Therese; Carlsson, Mats; Janvier, Miho; Fludra, Andrzej; Hassler, Donald M.; Grundy, Timothy; Sidher, Sunil; Guest, Steve; Leeks, Sarah; Fredvik, Terje; Young, Peter Bibcode: 2022cosp...44.2583G Altcode: With the launch of Solar Orbiter in February 2020, we are now able to fully explore the link between the solar activity on the Sun and the inner heliosphere. Elemental abundance measurements provide a key tracer to probe the source regions of the solar wind and to track it from the solar surface and corona to the heliosphere. Abundances of elements with low first ionisation potential (FIP) are enhanced in the corona relative to high-FIP elements, with respect to the photosphere. This is known as the FIP effect, which is measured as abundance bias (FIP bias) of low and high FIP elements. This effect is vital for understanding the flow of mass and energy through the solar atmosphere. The comparison between in-situ and remote sensing composition data, coupled with modelling, will allow us to trace back the source of heliospheric plasma. Solar Orbiter has a unique combination of in-situ and remote sensing instruments that will help to make such a comparison. In particular, the SPICE (Spectral Imaging of the Coronal Environment) EUV spectrometer records spectra in two wavelength bands, 70.4-79.0 nm and 97.3-104.9 nm. SPICE is designed to provide spectroheliograms using a core set of emission lines arising from ions of both low-FIP and high-FIP elements such as C, N, O, Ne, Mg, S and Fe. These lines are formed over a wide range of temperatures from 20,000 K to over 1 million K, enabling the analysis of the different layers of the solar atmosphere. SPICE spectroheliograms can be processed to produce FIP bias maps, which can be compared to in-situ measurements of the solar wind composition of the same elements. During the Solar Orbiter Cruise Phase, SPICE observed several active regions. We will present some of these observations and discuss the SPICE diagnostic potential to derive relative abundances (e.g., Mg/Ne) and the FIP bias in those regions. Title: A Spectroscopic Measurement of High Velocity Spray Plasma from an M-class Flare and Coronal Mass Ejection Authors: Young, Peter R. Bibcode: 2022arXiv220409542Y Altcode: Coronal mass ejection spray plasma associated with the M1.5-class flare of 16 February 2011 is found to exhibit a Doppler blue-shift of 850 km/s - the largest value yet reported from ultraviolet (UV) or extreme ultraviolet (EUV) spectroscopy of the solar disk and inner corona. The observation is unusual in that the emission line (Fe XII 193.51 A) is not observed directly, but the Doppler shift is so large that the blue-shifted component appears in a wavelength window at 192.82 A, intended to observe lines of O V, Fe XI and Ca XVII. The Fe XII 195.12 A emission line is used as a proxy for the rest component of 193.51 A. The observation highlights the risks of using narrow wavelength windows for spectrometer observations when observing highly-dynamic solar phenomena. The consequences of large Doppler shifts for ultraviolet solar spectrometers, including the upcoming Multi-slit Solar Explorer (MUSE) mission, are discussed. Title: Revised Analysis of Fe VII Authors: Kramida, Alexander; Ryabtsev, Alexander N.; Young, Peter R. Bibcode: 2022ApJS..258...37K Altcode: New spectrograms of multiply ionized iron have been recorded and analyzed, targeting the Fe VII spectrum. As a result, several previously unknown spectral lines and energy levels have been identified in this spectrum. These new data have been analyzed together with all previously published laboratory and astrophysical data on this spectrum. The energy levels have been interpreted using parametric calculations with Cowan codes. Radiative transition rates calculated in this work supplemented other previously published calculations in constructing a complete set of recommended transition probabilities. The ionization energy of Fe VII has been redetermined with a fivefold improvement in accuracy. Its new value is 1,007,928(20) cm-1, corresponding to 124.9671(25) eV. Title: First observations from the SPICE EUV spectrometer on Solar Orbiter Authors: Fludra, A.; Caldwell, M.; Giunta, A.; Grundy, T.; Guest, S.; Leeks, S.; Sidher, S.; Auchère, F.; Carlsson, M.; Hassler, D.; Peter, H.; Aznar Cuadrado, R.; Buchlin, É.; Caminade, S.; DeForest, C.; Fredvik, T.; Haberreiter, M.; Harra, L.; Janvier, M.; Kucera, T.; Müller, D.; Parenti, S.; Schmutz, W.; Schühle, U.; Solanki, S. K.; Teriaca, L.; Thompson, W. T.; Tustain, S.; Williams, D.; Young, P. R.; Chitta, L. P. Bibcode: 2021A&A...656A..38F Altcode: 2021arXiv211011252F
Aims: We present first science observations taken during the commissioning activities of the Spectral Imaging of the Coronal Environment (SPICE) instrument on the ESA/NASA Solar Orbiter mission. SPICE is a high-resolution imaging spectrometer operating at extreme ultraviolet (EUV) wavelengths. In this paper we illustrate the possible types of observations to give prospective users a better understanding of the science capabilities of SPICE.
Methods: We have reviewed the data obtained by SPICE between April and June 2020 and selected representative results obtained with different slits and a range of exposure times between 5 s and 180 s. Standard instrumental corrections have been applied to the raw data.
Results: The paper discusses the first observations of the Sun on different targets and presents an example of the full spectra from the quiet Sun, identifying over 40 spectral lines from neutral hydrogen and ions of carbon, oxygen, nitrogen, neon, sulphur, magnesium, and iron. These lines cover the temperature range between 20 000 K and 1 million K (10 MK in flares), providing slices of the Sun's atmosphere in narrow temperature intervals. We provide a list of count rates for the 23 brightest spectral lines. We show examples of raster images of the quiet Sun in several strong transition region lines, where we have found unusually bright, compact structures in the quiet Sun network, with extreme intensities up to 25 times greater than the average intensity across the image. The lifetimes of these structures can exceed 2.5 hours. We identify them as a transition region signature of coronal bright points and compare their areas and intensity enhancements. We also show the first above-limb measurements with SPICE above the polar limb in C III, O VI, and Ne VIII lines, and far off limb measurements in the equatorial plane in Mg IX, Ne VIII, and O VI lines. We discuss the potential to use abundance diagnostics methods to study the variability of the elemental composition that can be compared with in situ measurements to help confirm the magnetic connection between the spacecraft location and the Sun's surface, and locate the sources of the solar wind.
Conclusions: The SPICE instrument successfully performs measurements of EUV spectra and raster images that will make vital contributions to the scientific success of the Solar Orbiter mission. Title: An Analysis of Spikes in Atmospheric Imaging Assembly (AIA) Data Authors: Young, Peter R.; Viall, Nicholeen M.; Kirk, Michael S.; Mason, Emily I.; Chitta, Lakshmi Pradeep Bibcode: 2021SoPh..296..181Y Altcode: 2021arXiv210802624Y The Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) returns high-resolution images of the solar atmosphere in seven extreme ultraviolet (EUV) wavelength channels. The images are processed on the ground to remove intensity spikes arising from energetic particles hitting the instrument, and the despiked images are provided to the community. In this article, a three-hour series of images from the 171 Å channel obtained on 28 February 2017 was studied to investigate how often the despiking algorithm gave false positives caused by compact brightenings in the solar atmosphere. The latter were identified through spikes appearing in the same detector pixel for three consecutive frames. 1096 examples were found from the 900 image frames. These "three-spikes" were assigned to 126 dynamic solar features, and it is estimated that the three-spike method identifies 19% of the total number of features affected by despiking. For any ten-minute sequence of AIA 171 Å images there are around 37 solar features that have their intensity modified by despiking. The features are found in active regions, quiet Sun, and coronal holes and, in relation to solar surface area, there is a greater proportion within coronal holes. In 96% of the cases, the despiked structure is a compact brightening with a size of two arcsec or less, and the remaining 4% have narrow, elongated structures. By applying an EUV burst detection algorithm, we found that 96% of the events could be classified as EUV bursts. None of the spike events are rendered invisible by the AIA processing pipeline, but the total intensity over an event's lifetime can be reduced by up to 67%. Users are recommended to always restore the original intensities in AIA data when studying short-lived or rapidly evolving features that exhibit fine-scale structure. Title: Characterizing the Spectral Profiles of Mg II, C II and Si IV in Solar Flares Authors: Roy, Soumya; Tripathi, Durgesh; Young, Peter Bibcode: 2021AGUFMSH25E2128R Altcode: Solar flares are the most energetic phenomena in the solar atmosphere with consequences for space weather through the generation of solar energetic particles and/or CMEs. Despite tremendous advances in understanding their characteristics, the complete physics of their origin and response to plasma in various layers of the solar atmosphere is not fully developed. Here, we study the characteristics of the spectral line profiles during different stages of flares as a function of photospheric magnetic flux density and compare those with the characteristics observed in quiescent active regions and quiet sun. For this purpose, we use archival observations from the Interface Region Imaging Spectrograph (IRIS). For context purposes, we used full-disk observations from the Atmospheric Imaging Assembly (AIA). We use the line-of-sight (LOS) magnetograms obtained by the Helioseismic and Magnetic Imager (HMI). We characterize the self-absorption observed and optical depth from the line intensities as a function of the magnetic flux density, which shows a signature of precipitation. We also see the Mg II triplets going into emission co-spatially in the regions where flare ribbons appear later. We use the 2791.6 A line to localize the regions where the triplet lines are observed. These results are important for the physics of flares and can be useful in predicting the location of a flare kernel. Title: Calibrating Optical Distortions In The Solar Orbiter Spice Spectrograph Authors: Thompson, W.; Schühle, U.; Young, P. Bibcode: 2021AAS...23831302T Altcode: The Spectral Imaging of the Coronal Environment (SPICE) instrument on SolarOrbiter is a high-resolution imaging spectrometer operating at extremeultraviolet (EUV) wavelengths from 70.4-79.0 nm and 97.3-104.9 nm. Asingle-mirror off-axis paraboloid focuses the solar image onto the entranceslit of the spectrometer section. A Toroidal Variable Line Space (TVLS)grating images the entrance slit onto a pair of MCP-intensified APS detectors.Ray-tracing analysis prior to launch showed that the instrument was subject toa number of small image distortions which need to be corrected in the finaldata product. We compare the ray tracing results with measurements made inflight. Co-alignment with other telescopes on Solar Orbiter will also beexamined. Title: Future Prospects for Solar EUV and Soft X-ray Solar Spectroscopy Missions Authors: Young, Peter R. Bibcode: 2021FrASS...8...50Y Altcode: 2021arXiv210202943Y Future prospects for solar spectroscopy missions operating in the extreme ultraviolet (EUV) and soft X-ray (SXR) wavelength ranges, 1.2--1600~\AA, are discussed. NASA is the major funder of Solar Physics missions, and brief summaries of the opportunities for mission development under NASA are given. Upcoming major solar missions from other nations are also described. The methods of observing the Sun in the two wavelength ranges are summarized with a discussion of spectrometer types, imaging techniques and detector options. The major spectral features in the EUV and SXR regions are identified, and then the upcoming instruments and concepts are summarized. The instruments range from large spectrometers on dedicated missions, to tiny, low-cost CubeSats launched through rideshare opportunities. Title: The Phosphorus-Potassium Abundance Telescope Authors: Young, P.; Hartnett, H. E.; Hinkel, N. R.; Scowen, P. Bibcode: 2021BAAS...53c1234Y Altcode: Phosphorus and potassium are essential elements for understanding planetary habitability. Phosphorus is a key element in biological molecules involved in metabolism and RNA and DNA, but its low abundance in Earth's crust makes it a limiting nutrient in terrestrial ecosystems. The radioactive isotope 40K is the dominant heat source in planetary interiors for the first 1-2 gigayears and important thereafter. Interior heating is necessary for degassing, building an atmosphere, and maintaining a stable climate. Despite their importance, there are vey few stars with measured abundances of K and P due to difficulties in observing them from the ground. We propose a CubeSat with a moderately high resolution (R = 25,000) near-infrared (0.9-1.6 micron) spectrograph that will obtain precision abundances for P, K, and ancillary elements for 1000 bright, sun-like FGK main sequence stars. This represents an order of magnitude increase in the number of stars with P measurements and enables a robust statistical understanding of the habitability of the solar neighborhood from the perspective of these elements. Title: Heterogeneous R-Process Chromium and Titanium Ejecta from Core Collapse Supernova Ejecta Polluted Our Solar System Authors: Bose, M.; Schulte, J.; Vance, G.; Jansen, R. A.; Young, P. Bibcode: 2021LPI....52.1414B Altcode: Star explodes / Dust everywhere / Sprinkles metal. Title: CHIANTI—An Atomic Database for Emission Lines. XVI. Version 10, Further Extensions Authors: Del Zanna, G.; Dere, K. P.; Young, P. R.; Landi, E. Bibcode: 2021ApJ...909...38D Altcode: 2020arXiv201105211D We present version 10 of the CHIANTI package. In this release, we provide updated atomic models for several helium-like ions and for all the ions of the beryllium, carbon, and magnesium isoelectronic sequences that are abundant in astrophysical plasmas. We include rates from large-scale atomic structure and scattering calculations that are in many cases a significant improvement over the previous version, especially for the Be-like sequence, which has useful line diagnostics to measure the electron density and temperature. We have also added new ions and updated several of them with new atomic rates and line identifications. Also, we have added several improvements to the IDL software, to speed up the calculations and to estimate the suppression of dielectronic recombination. Title: The Coupled Role of Stellar Abundances, Exoplanet Radiogenic Heat Budgets and the Lifetime of Temperate Climates on Rocky Exoplanets Authors: Unterborn, C.; Foley, B.; Desch, S.; Young, P. Bibcode: 2021BAAS...53c1226U Altcode: A planet's heat budget is a combination of the retained heat of formation, the energy released due to the gravitational segregation of a Fe core and decay of the long-lived radionuclides U, Th and 40K. While secular cooling and the energy of core segregation are dependent on the formation history and magma ocean evolution, the amount of radiogenic heat a planet contains is solely a function of a planet's total amount of these elements. As refractory elements, U and Th are likely to exist in the same proportions relative to rock building elements in the planet as in the host-star. 40K is moderately volatile, and a planet's abundance is dependent on the degree of processing during planet formation. Recent observations of Solar twins show a range of stellar Th abundances between 60 and 250% of the Sun's (Unterborn et al., 2015), with similar ranges expected for U and bulk K. If this range of radionuclide compositions is indicative of the range of exoplanet radiogenic heat budgets, the thermal and chemical evolution of these planets may be quite different from the Earth.Here I present the results of recent coupled climate and convection models for 1-6 Earth mass stagnant lid planet with probabilistically determined radiogenic heat budgets constrained by observationally-determined abundances of U, Th and K. These models allow us to estimate the rates of surface volcanism, CO2 degassing from the interior and surface weathering processes. These models allow us to more realistically examine the short-, medium- and long-term climatic effects of varying radionuclide abundance given the different half-lives of the individual elements. An important output of our models is the lifetime of degassing across our parameter space. Using these degassing lifetimes, I will show that the habitable zone planets TRAPPIST-1 e, f and g are likely too old to be actively degassing today without additional tidal heating as an additional source of heat or the planets undergoing plate tectonics. Additionally, I will present a sample of observed rocky exoplanets both young and massive enough to be likely degassing today, making them prime targets in our search for planets with temperate climates. These results show the importance of estimating the age of a planetary system when assessing its likelihood to harbor Earth-like and habitable exoplanets. Title: Extreme-ultraviolet bursts and nanoflares in the quiet-Sun transition region and corona Authors: Chitta, L. P.; Peter, H.; Young, P. R. Bibcode: 2021A&A...647A.159C Altcode: 2021arXiv210200730C The quiet solar corona consists of myriads of loop-like features, with magnetic fields originating from network and internetwork regions on the solar surface. The continuous interaction between these different magnetic patches leads to transient brightenings or bursts that might contribute to the heating of the solar atmosphere. The literature on a variety of such burst phenomena in the solar atmosphere is rich. However, it remains unclear whether such transients, which are mostly observed in the extreme ultraviolet (EUV), play a significant role in atmospheric heating. We revisit the open question of these bursts as a prelude to the new high-resolution EUV imagery expected from the recently launched Solar Orbiter. We use EUV image sequences recorded by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) to investigate statistical properties of the bursts. We detect the bursts in the 171 Å filter images of AIA in an automated way through a pixel-wise analysis by imposing different intensity thresholds. By exploiting the high cadence (12 s) of the AIA observations, we find that the distribution of lifetimes of these events peaks at about 120 s. However, a significant number of events also have lifetimes shorter than 60 s. The sizes of the detected bursts are limited by the spatial resolution, which indicates that a larger number of events might be hidden in the AIA data. We estimate that about 100 new bursts appear per second on the whole Sun. The detected bursts have nanoflare-like energies of 1024 erg per event. Based on this, we estimate that at least 100 times more events of a similar nature would be required to account for the energy that is required to heat the corona. When AIA observations are considered alone, the EUV bursts discussed here therefore play no significant role in the coronal heating of the quiet Sun. If the coronal heating of the quiet Sun is mainly bursty, then the high-resolution EUV observations from Solar Orbiter may be able to reduce the deficit in the number of EUV bursts seen with SDO/AIA at least partly by detecting more such events. Title: Fe VII Emission Lines in the Wavelength Range 193-197 Å Authors: Young, Peter R.; Ryabtsev, Alexander N.; Landi, Enrico Bibcode: 2021ApJ...908..104Y Altcode: 2020arXiv201208027Y The identifications of Fe VII emission lines in the wavelength range 193-197 Å are discussed in the light of new measurements of laboratory spectra and atomic data calculations. This region is of importance to studies of solar spectra from the EUV Imaging Spectrometer (EIS) on board the Hinode spacecraft, which has its peak sensitivity at these wavelengths. Ten lines are measured, arising from seven fine structure levels in the 3p53d3 configuration. Two lines have not previously been reported and lead to new experimental energies for the ${({a}^{2}D)}^{3}{F}_{\mathrm{2,3}}$ levels. Updated experimental energies are obtained for the remaining levels. The new atomic model is used to compute theoretical values for the two density diagnostic ratios λ196.21/λ195.39 and λ196.21/λ196.06, and densities are derived from EIS spectra of coronal loop footpoints. Title: Shock Interaction/Breakout Explorer (SIBEX) Authors: Roming, P.; Bayless, A.; Brown, P.; Davis, M.; Echon, J.; Fryer, C.; Galeazzi, M.; Young, P.; Sibex Team Bibcode: 2021AAS...23731503R Altcode: We are performing a concept and feasibility study for a future mission that would perform wide-field X-ray imaging and localization, coupled with rapid far-UV follow-up, in order to probe the earliest manifestations of transient astrophysical events. Some of these transient sources include the shock breakout (SBO) of core-collapse supernovae, shock interaction of Type Ia SNe with a companion, electromagnetic counterparts to gravitational wave sources (e.g., kilonovae), tidal disruption events, cataclysmic variables, X-ray transients, and flaring from exoplanet host stars. We discuss the science objectives of the mission in the context of electromagnetic and multi-messenger astrophysics, as well as the overall mission concept and corresponding instrumentation. Title: New Online Undergraduate Degree in Astronomical and Planetary Sciences Authors: Knierman, K.; Groppi, C.; Ashcraft, T.; Coughlin, A.; Bahamonde, J.; Patience, J.; Butler, N.; Young, P.; Van Engelen, A.; Noble, A.; Monkiewicz, J.; Bowman, J.; Shkolnik, E.; Anbar, A.; Hunsley, D.; Sackey, S.; Bodin, M.; Miquirray, S.; Ray, K.; Loder, M. Bibcode: 2021AAS...23732301K Altcode: In Fall 2020, the School of Earth and Space Exploration at Arizona State University began its 100% online undergraduate degree in Astronomical and Planetary Sciences. This degree is one of the world's first online astronomy Bachelor of Science degrees. Offered through ASU Online, this innovative degree will prepare students for many careers including K-12 STEM teachers, technology and science journalism and writing, public outreach, science communication officer, science policy, statistical data analysis, and computer programming. The degree program includes groundwork in mathematics and physical sciences, topical courses focused on diverse fields within astronomy and planetary science, and exposure to the engineering and computational tools and techniques used to carry out research. Students who are interested in going to graduate school in Astrophysics would need additional advanced coursework not offered online beyond the degree including, but not limited to in-person research experience. We have developed new online courses and redesigned existing ones in support of this degree. By utilizing innovative learning techniques and technologies for the online realm, we are able to provide an interactive experience for online students. Our existing online introductory astronomy course, also taken by many non-majors, has been redesigned and features new online adaptive and interactive laboratory experiences created with the ASU Center of Education through eXploration (ETX). New project-based courses include the topics of Science Communication and Problem Solving and Programming using Python. Solving the problems of collaborative group work in online upper division courses has benefited from piloting new tools and technology in remotely taught in-person courses during the pandemic. In the 4 months since our launch in June 2020, over 100 students have been accepted into our degree program with numbers steadily increasing each week. Title: Relative coronal abundance diagnostics with Solar Orbiter/SPICE Authors: Zambrana Prado, N.; Buchlin, E.; Peter, H.; Young, P. R.; Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Aznar Cuadrado, R.; Caminade, S.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L.; Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.; Parenti, S.; Schmutz, W. K.; Schühle, U.; Sidher, S.; Teriaca, L.; Thompson, W. T.; Williams, D. Bibcode: 2020AGUFMSH038..09Z Altcode: Linking solar activity on the surface and in the corona to the inner heliosphere is one of Solar Orbiter's main goals. Its UV spectrometer SPICE (SPectral Imaging of the Coronal Environment) will provide relative abundance measurements which will be key in this quest as different structures on the Sun have different abundances as a consequence of the FIP (First Ionization Potential) effect. Solar Orbiter's unique combination of remote sensing and in-situ instruments coupled with observation from other missions such as Parker Solar Probe will allow us to compare in-situ and remote sensing composition data. With the addition of modeling, these new results will allow us to trace back the source of heliospheric plasma. As high telemetry will not always be available with SPICE, we have developed a method for measuring relative abundances that is both telemetry efficient and reliable. Unlike methods based on Differential Emission Measure (DEM) inversion, the Linear Combination Ratio (LCR) method does not require a large number of spectral lines. This new method is based on linear combinations of UV spectral lines. The coefficients of the combinations are optimized such that the ratio of two linear combinations of radiances would yield the relative abundance of two elements. We present some abundance diagnostics tested on different combinations of spectral lines observable by SPICE. Title: Dynamics and thermal structure in the quiet Sun seen by SPICE Authors: Peter, H.; Aznar Cuadrado, R.; Schühle, U.; Teriaca, L.; Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Buchlin, E.; Caminade, S.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L. K.; Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.; Parenti, S.; Schmutz, W. K.; Sidher, S.; Thompson, W. T.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH038..03P Altcode: We will present some of the early data of the Spectral Imaging of the Coronal Environment (SPICE) instrument on Solar Orbiter. One of the unique features of SPICE is its capability to record a wide range of wavelengths in the extreme UV with the possibility to record spectral lines giving access to a continuous plasma temperature range from 10.000 K to well above 1 MK. The data taken so far were for commissioning purposes and they can be used for a preliminary evaluation of the science performance of the instrument. Here we will concentrate on sample spectra covering the whole wavelength region and on the early raster maps acquired in bright lines in the quiet Sun close to disk center. Looking at different quiet Sun features we investigate the thermal structure of the atmosphere and flow structures. For this we apply fits to the spectral profiles and check the performance in terms of Doppler shifts and line widths to retrieve the structure of the network in terms of dynamics. While the amount of data available so far is limited, we will have a first look on how quiet Sun plasma responds to heating events. For this, we will compare spectral lines forming at different temperatures recorded at strictly the same time. Title: First Results From SPICE EUV Spectrometer on Solar Orbiter Authors: Fludra, A.; Caldwell, M.; Giunta, A. S.; Grundy, T.; Guest, S.; Sidher, S.; Auchere, F.; Carlsson, M.; Hassler, D.; Peter, H.; Aznar Cuadrado, R.; Buchlin, E.; Caminade, S.; DeForest, C.; Fredvik, T.; Harra, L. K.; Janvier, M.; Kucera, T. A.; Leeks, S.; Mueller, D.; Parenti, S.; Schmutz, W. K.; Schühle, U.; Teriaca, L.; Thompson, W. T.; Tustain, S.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH038..02F Altcode: SPICE (Spectral Imaging of Coronal Environment) is one of the remote sensing instruments onboard Solar Orbiter. It is an EUV imaging spectrometer observing the Sun in two wavelength bands: 69.6-79.4 nm and 96.6-105.1 nm. SPICE is capable of recording full spectra in these bands with exposures as short as 1s. SPICE is the only Solar Orbiter instrument that can measure EUV spectra from the disk and low corona of the Sun and record all spectral lines simultaneously. SPICE uses one of three narrow slits, 2"x11', 4''x11', 6''x11', or a wide slit 30''x14'. The primary mirror can be scanned in a direction perpendicular to the slit, allowing raster images of up to 16' in size.

We present an overview of the first SPICE data taken on several days during the instrument commissioning carried out by the RAL Space team between 2020 April 21 and 2020 June 14. We also include results from SPICE observations at the first Solar Orbiter perihelion at 0.52AU, taken between June 16-21st. We give examples of full spectra from the quiet Sun near disk centre and provide a list of key spectral lines emitted in a range of temperatures between 10,000 K and over 1 million K, from neutral hydrogen and ions of carbon, oxygen, nitrogen, neon, sulphur and magnesium. We show examples of first raster images in several strong lines, obtained with different slits and a range of exposure times between 5s and 180s. We describe the temperature coverage and density diagnostics, determination of plasma flows, and discuss possible applications to studies of the elemental abundances in the corona. We also show the first off-limb measurements with SPICE, as obtained when the spacecraft pointed at the limb. Title: Calibrating optical distortions in the Solar Orbiter SPICE spectrograph Authors: Thompson, W. T.; Schühle, U.; Young, P. R.; Auchere, F.; Carlsson, M.; Fludra, A.; Hassler, D.; Peter, H.; Aznar Cuadrado, R.; Buchlin, E.; Caldwell, M.; DeForest, C.; Fredvik, T.; Harra, L. K.; Janvier, M.; Kucera, T. A.; Giunta, A. S.; Grundy, T.; Müller, D.; Parenti, S.; Caminade, S.; Schmutz, W. K.; Teriaca, L.; Williams, D.; Sidher, S. Bibcode: 2020AGUFMSH0360029T Altcode: The Spectral Imaging of the Coronal Environment (SPICE) instrument on Solar Orbiter is a high-resolution imaging spectrometer operating at extreme ultraviolet (EUV) wavelengths from 70.4-79.0 nm and 97.3-104.9 nm. A single-mirror off-axis paraboloid focuses the solar image onto the entrance slit of the spectrometer section. A Toroidal Variable Line Space (TVLS) grating images the entrance slit onto a pair of MCP-intensified APS detectors. Ray-tracing analysis prior to launch showed that the instrument was subject to a number of small image distortions which need to be corrected in the final data product. We compare the ray tracing results with measurements made in flight. Co-alignment with other telescopes on Solar Orbiter will also be examined. Title: First results from the EUI and SPICE observations of Alpha Leo near Solar Orbiter first perihelion Authors: Buchlin, E.; Teriaca, L.; Giunta, A. S.; Grundy, T.; Andretta, V.; Auchere, F.; Peter, H.; Berghmans, D.; Carlsson, M.; Fludra, A.; Harra, L.; Hassler, D.; Long, D.; Rochus, P. L.; Schühle, U.; Aznar Cuadrado, R.; Caldwell, M.; Caminade, S.; DeForest, C.; Fredvik, T.; Gissot, S.; Heerlein, K.; Janvier, M.; Kraaikamp, E.; Kucera, T. A.; Müller, D.; Parenti, S.; Schmutz, W. K.; Sidher, S.; Smith, P.; Stegen, K.; Thompson, W. T.; Verbeeck, C.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH0360024B Altcode: On June 16th 2020 Solar Orbiter made a dedicated observing campaign where the spacecraft pointed to the solar limb to allow some of the high resolution instruments to observe the ingress (at the east limb) and later the egress (west limb) of the occultation of the star Alpha Leonis by the solar disk. The star was chosen because its luminosity and early spectral type ensure high and stable flux at wavelengths between 100 and 122 nanometers, a range observed by the High Resolution EUI Lyman alpha telescope (HRI-LYA) and by the long wavelength channel of the SPICE spectrograph. Star observations, when feasible, allow to gather a great deal of information on the instrument performances, such as the radiometric performance and the instrument optical point spread function (PSF).

We report here the first results from the above campaign for the two instruments. Title: Spectroscopic Constraints on the Dimension of Active Region Loops Along the Line of Sight Authors: Kucera, T. A.; Young, P. R.; Klimchuk, J. A.; DeForest, C. Bibcode: 2020AGUFMSH041..05K Altcode: Understanding the cross sections of coronal loops and how they vary along the loop is important both for understanding coronal heating and how the loops are shaped by the coronal magnetic field. To better address this question we have developed a new method to constrain the dimension of loops along the line of sight by utilizing spectroscopic observations. We apply this method to a cool (5.5<logT<6.2) loop using data from the Hinode/EUV Imaging Spectrometer (EIS) with supporting data from Solar Dynamic Observatory (SDO) and the Solar TErrestrial RElations Observatory (STEREO), and discuss the results and their limitations. Our results are consistent with circular loop cross sections, but could also be consistent with aspect ratios of 2 or 3. Title: First results from combined EUI and SPICE observations of Lyman lines of Hydrogen and He II Authors: Teriaca, L.; Aznar Cuadrado, R.; Giunta, A. S.; Grundy, T.; Parenti, S.; Auchere, F.; Vial, J. C.; Fludra, A.; Berghmans, D.; Carlsson, M.; Harra, L.; Hassler, D.; Long, D.; Peter, H.; Rochus, P. L.; Schühle, U.; Buchlin, E.; Caldwell, M.; Caminade, S.; DeForest, C.; Fredvik, T.; Gissot, S.; Heerlein, K.; Janvier, M.; Kraaikamp, E.; Kucera, T. A.; Mueller, D.; Schmutz, W. K.; Sidher, S.; Smith, P.; Stegen, K.; Thompson, W. T.; Verbeeck, C.; Williams, D.; Young, P. R. Bibcode: 2020AGUFMSH0360003T Altcode: The Solar Orbiter spacecraft carries a powerful set of remote sensing instruments that allow studying the solar atmosphere with unprecedented diagnostic capabilities. Many such diagnostics require the simultaneous usage of more than one instrument. One example of that is the capability, for the first time, to obtain (near) simultaneous spatially resolved observations of the emission from the first three lines of the Lyman series of hydrogen and of He II Lyman alpha. In fact, the SPectral Imaging of the Coronal Environment (SPICE) spectrometer can observe the Lyman beta and gamma lines in its long wavelength (SPICE-LW) channel, the High Resolution Lyman Alpha (HRI-LYA) telescope of the Extreme Ultraviolet Imager (EUI) acquires narrow band images in the Lyman alpha line while the Full Disk Imager (FSI) of EUI can take images dominated by the Lyman alpha line of ionized Helium at 30.4 nm (FSI-304). Being hydrogen and helium the main components of our star, these very bright transitions play an important role in the energy budget of the outer atmosphere via radiative losses and the measurement of their profiles and radiance ratios is a fundamental constraint to any comprehensive modelization effort of the upper solar chromosphere and transition region. Additionally, monitoring their average ratios can serve as a check out for the relative radiometric performance of the two instruments throughout the mission. Although the engineering data acquired so far are far from ideal in terms of time simultaneity (often only within about 1 h) and line coverage (often only Lyman beta was acquired by SPICE and not always near simultaneous images from all three telescopes are available) the analysis we present here still offers a great opportunity to have a first look at the potential of this diagnostic from the two instruments. In fact, we have identified a series of datasets obtained at disk center and at various positions at the solar limb that allow studying the Lyman alpha to beta radiance ratio and their relation to He II 30.4 as a function of the position on the Sun (disk center versus limb and quiet Sun versus coronal holes). Title: The Solar Orbiter Science Activity Plan. Translating solar and heliospheric physics questions into action Authors: Zouganelis, I.; De Groof, A.; Walsh, A. P.; Williams, D. R.; Müller, D.; St Cyr, O. C.; Auchère, F.; Berghmans, D.; Fludra, A.; Horbury, T. S.; Howard, R. A.; Krucker, S.; Maksimovic, M.; Owen, C. J.; Rodríguez-Pacheco, J.; Romoli, M.; Solanki, S. K.; Watson, C.; Sanchez, L.; Lefort, J.; Osuna, P.; Gilbert, H. R.; Nieves-Chinchilla, T.; Abbo, L.; Alexandrova, O.; Anastasiadis, A.; Andretta, V.; Antonucci, E.; Appourchaux, T.; Aran, A.; Arge, C. N.; Aulanier, G.; Baker, D.; Bale, S. D.; Battaglia, M.; Bellot Rubio, L.; Bemporad, A.; Berthomier, M.; Bocchialini, K.; Bonnin, X.; Brun, A. S.; Bruno, R.; Buchlin, E.; Büchner, J.; Bucik, R.; Carcaboso, F.; Carr, R.; Carrasco-Blázquez, I.; Cecconi, B.; Cernuda Cangas, I.; Chen, C. H. K.; Chitta, L. P.; Chust, T.; Dalmasse, K.; D'Amicis, R.; Da Deppo, V.; De Marco, R.; Dolei, S.; Dolla, L.; Dudok de Wit, T.; van Driel-Gesztelyi, L.; Eastwood, J. P.; Espinosa Lara, F.; Etesi, L.; Fedorov, A.; Félix-Redondo, F.; Fineschi, S.; Fleck, B.; Fontaine, D.; Fox, N. J.; Gandorfer, A.; Génot, V.; Georgoulis, M. K.; Gissot, S.; Giunta, A.; Gizon, L.; Gómez-Herrero, R.; Gontikakis, C.; Graham, G.; Green, L.; Grundy, T.; Haberreiter, M.; Harra, L. K.; Hassler, D. M.; Hirzberger, J.; Ho, G. C.; Hurford, G.; Innes, D.; Issautier, K.; James, A. W.; Janitzek, N.; Janvier, M.; Jeffrey, N.; Jenkins, J.; Khotyaintsev, Y.; Klein, K. -L.; Kontar, E. P.; Kontogiannis, I.; Krafft, C.; Krasnoselskikh, V.; Kretzschmar, M.; Labrosse, N.; Lagg, A.; Landini, F.; Lavraud, B.; Leon, I.; Lepri, S. T.; Lewis, G. R.; Liewer, P.; Linker, J.; Livi, S.; Long, D. M.; Louarn, P.; Malandraki, O.; Maloney, S.; Martinez-Pillet, V.; Martinovic, M.; Masson, A.; Matthews, S.; Matteini, L.; Meyer-Vernet, N.; Moraitis, K.; Morton, R. J.; Musset, S.; Nicolaou, G.; Nindos, A.; O'Brien, H.; Orozco Suarez, D.; Owens, M.; Pancrazzi, M.; Papaioannou, A.; Parenti, S.; Pariat, E.; Patsourakos, S.; Perrone, D.; Peter, H.; Pinto, R. F.; Plainaki, C.; Plettemeier, D.; Plunkett, S. P.; Raines, J. M.; Raouafi, N.; Reid, H.; Retino, A.; Rezeau, L.; Rochus, P.; Rodriguez, L.; Rodriguez-Garcia, L.; Roth, M.; Rouillard, A. P.; Sahraoui, F.; Sasso, C.; Schou, J.; Schühle, U.; Sorriso-Valvo, L.; Soucek, J.; Spadaro, D.; Stangalini, M.; Stansby, D.; Steller, M.; Strugarek, A.; Štverák, Š.; Susino, R.; Telloni, D.; Terasa, C.; Teriaca, L.; Toledo-Redondo, S.; del Toro Iniesta, J. C.; Tsiropoula, G.; Tsounis, A.; Tziotziou, K.; Valentini, F.; Vaivads, A.; Vecchio, A.; Velli, M.; Verbeeck, C.; Verdini, A.; Verscharen, D.; Vilmer, N.; Vourlidas, A.; Wicks, R.; Wimmer-Schweingruber, R. F.; Wiegelmann, T.; Young, P. R.; Zhukov, A. N. Bibcode: 2020A&A...642A...3Z Altcode: 2020arXiv200910772Z Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand how the Sun produces and controls the heliosphere, filling the Solar System and driving the planetary environments. With six remote-sensing and four in-situ instrument suites, the coordination and planning of the operations are essential to address the following four top-level science questions: (1) What drives the solar wind and where does the coronal magnetic field originate?; (2) How do solar transients drive heliospheric variability?; (3) How do solar eruptions produce energetic particle radiation that fills the heliosphere?; (4) How does the solar dynamo work and drive connections between the Sun and the heliosphere? Maximising the mission's science return requires considering the characteristics of each orbit, including the relative position of the spacecraft to Earth (affecting downlink rates), trajectory events (such as gravitational assist manoeuvres), and the phase of the solar activity cycle. Furthermore, since each orbit's science telemetry will be downloaded over the course of the following orbit, science operations must be planned at mission level, rather than at the level of individual orbits. It is important to explore the way in which those science questions are translated into an actual plan of observations that fits into the mission, thus ensuring that no opportunities are missed. First, the overarching goals are broken down into specific, answerable questions along with the required observations and the so-called Science Activity Plan (SAP) is developed to achieve this. The SAP groups objectives that require similar observations into Solar Orbiter Observing Plans, resulting in a strategic, top-level view of the optimal opportunities for science observations during the mission lifetime. This allows for all four mission goals to be addressed. In this paper, we introduce Solar Orbiter's SAP through a series of examples and the strategy being followed. Title: The Solar Orbiter SPICE instrument. An extreme UV imaging spectrometer Authors: SPICE Consortium; Anderson, M.; Appourchaux, T.; Auchère, F.; Aznar Cuadrado, R.; Barbay, J.; Baudin, F.; Beardsley, S.; Bocchialini, K.; Borgo, B.; Bruzzi, D.; Buchlin, E.; Burton, G.; Büchel, V.; Caldwell, M.; Caminade, S.; Carlsson, M.; Curdt, W.; Davenne, J.; Davila, J.; Deforest, C. E.; Del Zanna, G.; Drummond, D.; Dubau, J.; Dumesnil, C.; Dunn, G.; Eccleston, P.; Fludra, A.; Fredvik, T.; Gabriel, A.; Giunta, A.; Gottwald, A.; Griffin, D.; Grundy, T.; Guest, S.; Gyo, M.; Haberreiter, M.; Hansteen, V.; Harrison, R.; Hassler, D. M.; Haugan, S. V. H.; Howe, C.; Janvier, M.; Klein, R.; Koller, S.; Kucera, T. A.; Kouliche, D.; Marsch, E.; Marshall, A.; Marshall, G.; Matthews, S. A.; McQuirk, C.; Meining, S.; Mercier, C.; Morris, N.; Morse, T.; Munro, G.; Parenti, S.; Pastor-Santos, C.; Peter, H.; Pfiffner, D.; Phelan, P.; Philippon, A.; Richards, A.; Rogers, K.; Sawyer, C.; Schlatter, P.; Schmutz, W.; Schühle, U.; Shaughnessy, B.; Sidher, S.; Solanki, S. K.; Speight, R.; Spescha, M.; Szwec, N.; Tamiatto, C.; Teriaca, L.; Thompson, W.; Tosh, I.; Tustain, S.; Vial, J. -C.; Walls, B.; Waltham, N.; Wimmer-Schweingruber, R.; Woodward, S.; Young, P.; de Groof, A.; Pacros, A.; Williams, D.; Müller, D. Bibcode: 2020A&A...642A..14S Altcode: 2019arXiv190901183A; 2019arXiv190901183S
Aims: The Spectral Imaging of the Coronal Environment (SPICE) instrument is a high-resolution imaging spectrometer operating at extreme ultraviolet wavelengths. In this paper, we present the concept, design, and pre-launch performance of this facility instrument on the ESA/NASA Solar Orbiter mission.
Methods: The goal of this paper is to give prospective users a better understanding of the possible types of observations, the data acquisition, and the sources that contribute to the instrument's signal.
Results: The paper discusses the science objectives, with a focus on the SPICE-specific aspects, before presenting the instrument's design, including optical, mechanical, thermal, and electronics aspects. This is followed by a characterisation and calibration of the instrument's performance. The paper concludes with descriptions of the operations concept and data processing.
Conclusions: The performance measurements of the various instrument parameters meet the requirements derived from the mission's science objectives. The SPICE instrument is ready to perform measurements that will provide vital contributions to the scientific success of the Solar Orbiter mission. Title: The Supernova Origins of Rare Stardust Enriched with 13C and 15N Authors: Schulte, J.; Bose, M.; Young, P.; Vance, G. Bibcode: 2020LPI....51.1268S Altcode: New 15 solar mass 3D supernova models can successfully explain several isotope systems of many grains with enrichments in 13C and 15N. Title: Procedure for Observing Rocky Exoplanets to Maximize the Likelihood of Atmospheric Oxygen Biosignatures Authors: Lisse, C. M.; Desch, S. J.; Unterborn, C. T.; Kane, S. R.; Young, P. R.; Hartnett, H. E.; Hinkel, N. R.; Shim, S. -H.; Mamajek, E. E. Bibcode: 2020LPICo2195.3064L Altcode: We present a gated observational strategy to help prioritize exoplanet oxygen biosignature observations, in order to obtain the clearest, most interpretable O2 biosignature information possible. Title: Impact of small-scale emerging flux from the photosphere to the corona: a case study from IRIS Authors: Guglielmino, Salvo L.; Young, Peter R.; Zuccarello, Francesca; Romano, Paolo; Murabito, Mariarita Bibcode: 2020IAUS..354..439G Altcode: We report on multi-wavelength ultraviolet (UV) high-resolution observations taken with the IRIS satellite during the emergence phase of an emerging flux region embedded in the unipolar plage of active region NOAA 12529. These data are complemented by measurements taken with the spectropolarimeter aboard the Hinode satellite and by observations from SDO. Title: The Sun: Our own backyard plasma laboratory Authors: Young, Peter R. Bibcode: 2020IAUS..350..333Y Altcode: The Sun's atmosphere increases in temperature from 6000 degrees at the surface to over a million degrees at heights of a few thousand kilometers. This surprising temperature increase is still an active area of scientific study, but is generally thought to be driven by the dynamics of the Sun's magnetic field. The combination of a 2-to-3 order of magnitude temperature range and a low plasma density makes the solar atmosphere perhaps the best natural laboratory for the study of ionized atoms. Atomic transitions at ultraviolet (UV) and X-ray wavelength regions generally show no optical depth effects, and the lines are not subject to the interstellar absorption that affects astronomical sources. Here I highlight the importance of atomic data to modeling UV and X-ray solar spectra, with a particular focus on the CHIANTI atomic database. Atomic data needs and problems are discussed and future solar mission concepts presented. Title: The biogeosciences are a critical step on the path toward detecting life on exoplanets Authors: Hartnett, H. E.; Hinkel, N. R.; Anbar, A. D.; Desch, S. J.; Fisher, T.; Furukawa, H.; Glaser, D.; Okie, J. G.; Unterborn, C. T.; Vergeli, P.; Walker, S.; Young, P. Bibcode: 2019AGUFM.B13C..11H Altcode: Biogeosciences as a branch of the Earth and Life Sciences integrates theory from geology, chemistry, biology and physics to address questions across spatial and temporal scales including the very large and the very long. The biogeosciences evolved from studies of the modern Earth, but they are relevant for Earth's deep past and even for exoplanets. Thus, we can now also consider astrophysics to lie within the context of the biogeosciences. Exoplanets may provide the ultimate test of our understanding of biogeochemical cycles. Planets around other stars may be habitable, but our challenge for detecting life on these planets will be to distinguish the BIOgeochemical rates and fluxes of a living planet, from the strictly geochemical and physical processes of an abiotic planet. Ecosystem stoichiometry (e.g., Sterner and Elser, 2002) is a powerful theory based on the conservation of matter and energy that provides insight into interactions between organisms and environments at both the individual and the ecosystem scale. However, our knowledge of the ratios of biogeochemically relevant elements available on exoplanets is very limited, and hinders our ability to predict planetary-scale biogeochemical processes. Here we compare the ratios of bioessential and rock-forming elements (e.g., C, N, P, S, and Mg, Si, Ca, Fe) for living systems, for our Solar System, and for nearby stars (Table 1). For example, P is critical for life on Earth but its distribution in our solar system is quite variable. Molar C:P ratios for a Redfield approximation of plankton (e.g., C:P = 106) differ markedly from C:P ratios for Earth's crust (2) and for our Sun (~2200). The very limited available P data from the Hypatia Catalog of stellar elemental abundances reveals that nearby stars have C:P = ~800, suggesting our Sun might be comparatively P-depleted. This wide range in C:P and in other elemental ratios result from differences in stellar composition, planet formation and differentiation processes, and possibly the presence of life. Future work to detect life on exoplanets will require a coordinated effort over the next centennial, where the biogeosciences provide a crucial theoretical framework that informs data collection and modelling from astrophysics and planetary science. Title: Spectroscopic Constraints on the Cross-sectional Asymmetry and Expansion of Active Region Loops Authors: Kucera, T. A.; Young, P. R.; Klimchuk, J. A.; DeForest, C. E. Bibcode: 2019ApJ...885....7K Altcode: We explore the constraints that can be placed on the dimensions of coronal loops out of the plane of the sky by utilizing spectroscopic observations from the Hinode/EUV Imaging Spectrometer (EIS). The usual assumption is that loop cross sections are circular. Changes in intensity are assumed to be the result of changing density, filling factor, and/or point of view. In this work we instead focus on the possibility that the loop dimensions may be changing along the line of sight while the filling factor remains constant. We apply these ideas to two warm (5.5≲ {log}T({{K}})< 6.2) loops observed by EIS in Active Region 11150 on 2011 February 6 with supporting observations from Solar Dynamics Observatory's Atmospheric Imaging Assembly and the Solar TErrestrial RElations Observatory-A's Extreme Ultraviolet Imager. Our results are generally consistent with nonexpanding loops but could also allow linear expansions of up to a factor of 2.5 along a 40 Mm section of one loop and up to a factor of 3.9 in another loop, both under the assumption that the filling factor is constant along the loop. Expansions in the plane of the sky over the same sections of the loops are 1.5 or less. For a filling factor of 1, the results of the analysis are consistent with circular cross sections but also with aspect ratios of 2 or greater. Count rate statistics are an important part of the uncertainties, but the results are also significantly dependent on radiometric calibration of EIS and the selection of the loop backgrounds. Title: Achievements of Hinode in the first eleven years Authors: Hinode Review Team; Al-Janabi, Khalid; Antolin, Patrick; Baker, Deborah; Bellot Rubio, Luis R.; Bradley, Louisa; Brooks, David H.; Centeno, Rebecca; Culhane, J. Leonard; Del Zanna, Giulio; Doschek, George A.; Fletcher, Lyndsay; Hara, Hirohisa; Harra, Louise K.; Hillier, Andrew S.; Imada, Shinsuke; Klimchuk, James A.; Mariska, John T.; Pereira, Tiago M. D.; Reeves, Katharine K.; Sakao, Taro; Sakurai, Takashi; Shimizu, Toshifumi; Shimojo, Masumi; Shiota, Daikou; Solanki, Sami K.; Sterling, Alphonse C.; Su, Yingna; Suematsu, Yoshinori; Tarbell, Theodore D.; Tiwari, Sanjiv K.; Toriumi, Shin; Ugarte-Urra, Ignacio; Warren, Harry P.; Watanabe, Tetsuya; Young, Peter R. Bibcode: 2019PASJ...71R...1H Altcode: Hinode is Japan's third solar mission following Hinotori (1981-1982) and Yohkoh (1991-2001): it was launched on 2006 September 22 and is in operation currently. Hinode carries three instruments: the Solar Optical Telescope, the X-Ray Telescope, and the EUV Imaging Spectrometer. These instruments were built under international collaboration with the National Aeronautics and Space Administration and the UK Science and Technology Facilities Council, and its operation has been contributed to by the European Space Agency and the Norwegian Space Center. After describing the satellite operations and giving a performance evaluation of the three instruments, reviews are presented on major scientific discoveries by Hinode in the first eleven years (one solar cycle long) of its operation. This review article concludes with future prospects for solar physics research based on the achievements of Hinode. Title: Multi-component Decomposition of Astronomical Spectra by Compressed Sensing Authors: Cheung, Mark C. M.; De Pontieu, Bart; Martínez-Sykora, Juan; Testa, Paola; Winebarger, Amy R.; Daw, Adrian; Hansteen, Viggo; Antolin, Patrick; Tarbell, Theodore D.; Wuelser, Jean-Pierre; Young, Peter; MUSE Team Bibcode: 2019ApJ...882...13C Altcode: 2019arXiv190203890C The signal measured by an astronomical spectrometer may be due to radiation from a multi-component mixture of plasmas with a range of physical properties (e.g., temperature, Doppler velocity). Confusion between multiple components may be exacerbated if the spectrometer sensor is illuminated by overlapping spectra dispersed from different slits, with each slit being exposed to radiation from a different portion of an extended astrophysical object. We use a compressed sensing method to robustly retrieve the different components. This method can be adopted for a variety of spectrometer configurations, including single-slit, multi-slit (e.g., the proposed MUlti-slit Solar Explorer mission), and slot spectrometers (which produce overlappograms). Title: Plasmoid-mediated reconnection in solar UV bursts Authors: Peter, H.; Huang, Y. -M.; Chitta, L. P.; Young, P. R. Bibcode: 2019A&A...628A...8P Altcode: 2019arXiv190704335P Context. Ultraviolet bursts are transients in the solar atmosphere with an increased impulsive emission in the extreme UV lasting for one to several tens of minutes. They often show spectral profiles indicative of a bi-directional outflow in response to magnetic reconnection.
Aims: To understand UV bursts, we study how motions of magnetic elements at the surface can drive the self-consistent formation of a current sheet resulting in plasmoid-mediated reconnection. In particular, we want to study the role of the height of the reconnection in the atmosphere.
Methods: We conducted numerical experiments solving the 2D magnetohydrodynamic equations from the solar surface to the upper atmosphere. Motivated by observations, we drove a small magnetic patch embedded in a larger system of magnetic field of opposite polarity. This type of configuration creates an X-type neutral point in the initial potential field. The models are characterized by the (average) plasma-β at the height of this X point.
Results: The driving at the surface stretches the X-point into a thin current sheet, where plasmoids appear, accelerating the reconnection, and a bi-directional jet forms. This is consistent with what is expected for UV bursts or explosive events, and we provide a self-consistent model of the formation of the reconnection region in such events. The gravitational stratification gives a natural explanation for why explosive events are restricted to a temperature range around a few 0.1 MK, and the presence of plasmoids in the reconnection process provides an understanding of the observed variability during the transient events on a timescale of minutes.
Conclusions: Our numerical experiments provide a comprehensive understanding of UV bursts and explosive events, in particular of how the atmospheric response changes if the reconnection happens at different plasma-β, that is, at different heights in the atmosphere. This analysis also gives new insight into how UV bursts might be related to the photospheric Ellerman bombs.

Movie attached to Fig. 2 is available at https://www.aanda.org Title: Constraints from Hinode/EIS on the Expansion of Active Region Loops Along the Line of Sight Authors: Kucera, Therese A.; Young, Peter R.; Klimchuk, James A.; DeForest, Craig Bibcode: 2019AAS...23411706K Altcode: We explore the constraints that can be placed on the dimensions of coronal loops out of the plane of the sky by utilizing spectroscopic observations from the Hinode/EUV Imaging Spectrometer (EIS). The usual assumption is that loop cross sections are circular. Changes in intensity not constant with the measured width are assumed to be the result of changing density and/or filling factor. Here we instead focus on the possibility that the loop dimensions may be changing along the line of sight while the filling factor remains constant. We apply these ideas to two cool (5.5<logT<6.2) loops observed by EIS with supporting observations from Solar Dynamics Observatory's Atmospheric Imaging Assembly (SDO/AIA) and the Solar TErrestrial RElations Observatory-A's Extreme Ultraviolet Imager (STEREO-A/EUVI). Our results are generally consistent with non-expanding loops, but allow for line-of-sight expansion factors up to 3-4. The uncertainties are sizable and are driven by count rate statistics, radiometric calibration of EIS, and the selection of the loop backgrounds. Title: Magnetic reconnection in the low atmosphere: Ellerman bombs and UV bursts Authors: Young, Peter R. Bibcode: 2019AAS...23422606Y Altcode: Ellerman bombs (EBs) were first discovered over a hundred years ago and are widely interpreted as magnetic reconnection events occurring deep in the atmosphere. UV bursts have been actively studied since the launch of IRIS in 2013 and show many similarities to EBs, but significantly give a strong signature in the Si IV emission lines that indicate hotter temperatures. The interpretation is again magnetic reconnection, but in a higher layer of the atmosphere or with a different magnetic geometry.

The expected small spatial scales of magnetic reconnection, and the tantalizing hints from recent high resolution ground observations suggest that EBs and UV bursts will be an ideal demonstration of DKIST's capabilities. This talk summarizes recent results on EBs and UV bursts and identifies key observational capabilities of DKIST. Title: Multi-component Decomposition of Astronomical Spectra by Compressed Sensing Authors: Cheung, Mark; De Pontieu, Bart; Martinez-Sykora, Juan; Testa, Paola; Winebarger, Amy R.; Daw, Adrian N.; Hansteen, Viggo; Antolin, Patrick; Tarbell, Theodore D.; Wuelser, Jean-Pierre; Young, Peter R. Bibcode: 2019AAS...23411603C Altcode: The signal measured by an astronomical spectrometer may be due to radiation from a multi-component mixture of plasmas with a range of physical properties (e.g. temperature, Doppler velocity). Confusion between multiple components may be exacerbated if the spectrometer sensor is illuminated by overlapping spectra dispersed from different slits, with each slit being exposed to radiation from a different portion of an extended astrophysical object. We use a compressed sensing method to robustly retrieve the different components. This method can be adopted for a variety of spectrometer configurations, including single-slit, multi-slit (e.g., the proposed MUlti-slit Solar Explorer mission; MUSE) and slot spectrometers (which produce overlappograms). Title: Using Symmetric and Asymmetric Three-Dimensional Supernova Models to Constrain the Origins of Presolar SiC Grains Authors: Schulte, J.; Bose, M.; Young, P.; Vance, G. Bibcode: 2019LPI....50.1746S Altcode: Asymmetric 3-dimensional supernova models are a good fit to the presolar SiC X grain isotopic compositions. Title: SI IV Resonance Line Emission during Solar Flares: Non-LTE, Nonequilibrium, Radiation Transfer Simulations Authors: Kerr, Graham S.; Carlsson, Mats; Allred, Joel C.; Young, Peter R.; Daw, Adrian N. Bibcode: 2019ApJ...871...23K Altcode: 2018arXiv181111075K The Interface Region Imaging Spectrograph routinely observes the Si IV resonance lines. When analyzing quiescent observations of these lines, it has typically been assumed that they form under optically thin conditions. This is likely valid for the quiescent Sun, but this assumption has also been applied to the more extreme flaring scenario. We used 36 electron-beam-driven radiation hydrodynamic solar flare simulations, computed using the RADYN code, to probe the validity of this assumption. Using these simulated atmospheres, we solved the radiation transfer equations to obtain the non-LTE, nonequilibrium populations, line profiles, and opacities for a model silicon atom, including charge exchange processes. This was achieved using the “minority species” version of RADYN. The inclusion of charge exchange resulted in a substantial fraction of Si IV at cooler temperatures than those predicted by ionization equilibrium. All simulations with an injected energy flux F> 5× {10}10 erg cm-2 s-1 resulted in optical depth effects on the Si IV emission, with differences in both intensity and line shape compared to the optically thin calculation. Weaker flares (down to F ≈ 5 × 109 erg cm-2 s-1) also resulted in Si IV emission forming under optically thick conditions, depending on the other beam parameters. When opacity was significant, the atmospheres generally had column masses in excess of 5 × 10-6 g cm-2 over the temperature range 40-100 kK, and the Si IV formation temperatures were between 30 and 60 kK. We urge caution when analyzing Si IV flare observations, or when computing synthetic emission without performing a full radiation transfer calculation. Title: Satellite observations of reconnection between emerging and pre-existing small-scale magnetic fields Authors: Guglielmino, S. L.; Zuccarello, F.; Young, P. R.; Romano, P.; Murabito, M. Bibcode: 2019NCimC..42...33G Altcode: 2019arXiv190101056G We report multi-wavelength ultraviolet observations taken with the IRIS satellite, concerning the emergence phase in the upper chromosphere and transition region of an emerging flux region (EFR) embedded in the unipolar plage of active region NOAA 12529. The photospheric configuration of the EFR is analyzed in detail benefitting from measurements taken with the spectropolarimeter aboard the Hinode satellite, when the EFR was fully developed. In addition, these data are complemented by full-disk, simultaneous observations of the SDO satellite, relevant to the photosphere and the corona. In the photosphere, magnetic flux emergence signatures are recognized in the fuzzy granulation, with dark alignments between the emerging polarities, cospatial with highly inclined fields. In the upper atmospheric layers, we identify recurrent brightenings that resemble UV bursts, with counterparts in all coronal passbands. These occur at the edges of the EFR and in the region of the arch filament system (AFS) cospatial to the EFR. Jet activity is also found at chromospheric and coronal levels, near the AFS and the observed brightness enhancement sites. The analysis of the IRIS line profiles reveals the heating of dense plasma in the low solar atmosphere and the driving of bi-directional high-velocity flows with speeds up to 100 km/s at the same locations. Furthermore, we detect a correlation between the Doppler velocity and line width of the Si IV 1394 and 1402 Å line profiles in the UV burst pixels and their skewness. Comparing these findings with previous observations and numerical models, we suggest evidence of several long-lasting, small-scale magnetic reconnection episodes between the emerging bipole and the ambient field. This process leads to the cancellation of a pre-existing photospheric flux concentration of the plage with the opposite polarity flux patch of the EFR. The reconnection appears to occur higher in the atmosphere than usually observed. Title: IRIS Observations of Magnetic Interactions in the Solar Atmosphere between Preexisting and Emerging Magnetic Fields. II. UV Emission Properties Authors: Guglielmino, Salvo L.; Young, Peter R.; Zuccarello, Francesca Bibcode: 2019ApJ...871...82G Altcode: 2018arXiv181207285G Multiwavelength ultraviolet (UV) observations by the Interface Region Imaging Spectrograph satellite in active region NOAA 12529 have recently pointed out the presence of long-lasting brightenings, akin to UV bursts, and simultaneous plasma ejections occurring in the upper chromosphere and transition region during secondary flux emergence. These signatures have been interpreted as evidence of small-scale, recurrent magnetic reconnection episodes between the emerging flux region (EFR) and the preexisting plage field. Here we characterize the UV emission of these strong, intermittent brightenings and study the surge activity above the chromospheric arch filament system (AFS) overlying the EFR. We analyze the surges and the cospatial brightenings observed at different wavelengths. We find an asymmetry in the emission between the blue and red wings of the Si IV λ1402 Å and Mg II k λ2796.3 lines, which clearly outlines the dynamics of the structures above the AFS that form during the small-scale eruptive phenomena. We also detect a correlation between the Doppler velocity and skewness of the Si IV λλ1394 and 1402 line profiles in the UV burst pixels. Finally, we show that genuine emission in the Fe XII λ1349.4 line is cospatial to the Si IV brightenings. This definitely reveals a pure coronal counterpart to the reconnection event. Title: Solar Ultraviolet Bursts Authors: Young, Peter R.; Tian, Hui; Peter, Hardi; Rutten, Robert J.; Nelson, Chris J.; Huang, Zhenghua; Schmieder, Brigitte; Vissers, Gregal J. M.; Toriumi, Shin; Rouppe van der Voort, Luc H. M.; Madjarska, Maria S.; Danilovic, Sanja; Berlicki, Arkadiusz; Chitta, L. P.; Cheung, Mark C. M.; Madsen, Chad; Reardon, Kevin P.; Katsukawa, Yukio; Heinzel, Petr Bibcode: 2018SSRv..214..120Y Altcode: 2018arXiv180505850Y The term "ultraviolet (UV) burst" is introduced to describe small, intense, transient brightenings in ultraviolet images of solar active regions. We inventorize their properties and provide a definition based on image sequences in transition-region lines. Coronal signatures are rare, and most bursts are associated with small-scale, canceling opposite-polarity fields in the photosphere that occur in emerging flux regions, moving magnetic features in sunspot moats, and sunspot light bridges. We also compare UV bursts with similar transition-region phenomena found previously in solar ultraviolet spectrometry and with similar phenomena at optical wavelengths, in particular Ellerman bombs. Akin to the latter, UV bursts are probably small-scale magnetic reconnection events occurring in the low atmosphere, at photospheric and/or chromospheric heights. Their intense emission in lines with optically thin formation gives unique diagnostic opportunities for studying the physics of magnetic reconnection in the low solar atmosphere. This paper is a review report from an International Space Science Institute team that met in 2016-2017. Title: Extracting Solar Physics from 151 Million EUV Images Authors: Kirk, Michael S.; Thompson, Barbara; Attie, Raphael; Viall-Kepko, Nicki; Young, Peter Bibcode: 2018csc..confE..88K Altcode: Beginning in 2010, the Solar Dynamics Observatory's Atmospheric Imaging Assembly (SDO AIA) revolutionized solar imaging with its high temporal and spatial resolution and coverage. The archive of extreme ultraviolet (EUV) images is now over 150 million and continues to grow. Automated algorithms consistently clean these images to remove magnetospheric particle impacts on the CCD cameras, but it has been found that compact, intense solar brightenings are often removed as well. There are now over 3 trillion "spiked pixels" that have been removed from EUV images. We estimate that 0.001% of those are of solar origin and removed by mistake - an unexplored dataset of about 30 million events. We take a novel approach and survey the entire set of AIA "spike" data to identify and group compact brightenings across the entire SDO mission. We then use the spike database to form statistics on compact solar brightenings without having to process large volumes of full-disk AIA data. The qualities of the "spikes" with a solar origin represent the most complete archive of compact EUV bright points ever assembled. Title: Predictions of DKIST/DL-NIRSP Observations for an Off-limb Kink-unstable Coronal Loop Authors: Snow, B.; Botha, G. J. J.; Scullion, E.; McLaughlin, J. A.; Young, P. R.; Jaeggli, S. A. Bibcode: 2018ApJ...863..172S Altcode: 2018arXiv180704972S Synthetic intensity maps are generated from a 3D kink-unstable flux rope simulation using several DKIST/DL-NIRSP spectral lines to make a prediction of the observational signatures of energy transport and release. The reconstructed large field-of-view intensity mosaics and single tile sit-and-stare high-cadence image sequences show detailed, fine-scale structure and exhibit signatures of wave propagation, redistribution of heat, flows, and fine-scale bursts. These fine-scale bursts are present in the synthetic Doppler velocity maps and can be interpreted as evidence for small-scale magnetic reconnection at the loop boundary. The spectral lines reveal the different thermodynamic structures of the loop, with the hotter lines showing the loop interior and braiding and the cooler lines showing the radial edges of the loop. The synthetic observations of DL-NIRSP are found to preserve the radial expansion, and hence the loop radius can be measured accurately. The electron number density can be estimated using the intensity ratio of the Fe XIII lines at 10747 and 10798 Å. The estimated density from this ratio is correct to within ±10% during the later phases of the evolution; however, it is less accurate initially when line-of-sight density inhomogeneities contribute to the Fe XIII intensity, resulting in an overprediction of the density by ≈30%. The identified signatures are all above a conservative estimate for instrument noise and therefore will be detectable. In summary, we have used forward modeling to demonstrate that the coronal off-limb mode of DKIST/DL-NIRSP will be able to detect multiple independent signatures of a kink-unstable loop and observe small-scale transient features including loop braiding/twisting and small-scale reconnection events occurring at the radial edge of the loop. Title: A Study of 37 UV Bursts Observed by IRIS Authors: Young, Peter Bibcode: 2018tess.conf30599Y Altcode: Ultraviolet bursts are intense, transient, compact brightenings found in active regions that emit strongly in the transition region Si IV emission lines observed by IRIS. They are believed to be small-scale magnetic reconnection events that occur low in the solar atmosphere, and thus they provide an alternative means for investigating reconnection compared to coronal flares and nanoflares, with the advantage that the magnetic evolution is very clearly seen.

Thirty-seven UV bursts are identified in a four hour active region IRIS observation from 2013 October 22, and their properties compared. In particular, we find bursts associated with moving magnetic features, a sunspot light bridge and emerging flux. Statistics are provided in terms of: magnetic field strengths, Si IV line profile shape parameters, coronal and chromospheric signatures, electron density, sizes and durations.The events will also be placed in context with other bursts that have been reported in the literature. Title: IRIS Observations of Magnetic Interactions in the Solar Atmosphere between Preexisting and Emerging Magnetic Fields. I. Overall Evolution Authors: Guglielmino, Salvo L.; Zuccarello, Francesca; Young, Peter R.; Murabito, Mariarita; Romano, Paolo Bibcode: 2018ApJ...856..127G Altcode: 2018arXiv180205657G We report multiwavelength ultraviolet observations taken with the IRIS satellite, concerning the emergence phase in the upper chromosphere and transition region of an emerging flux region (EFR) embedded in the preexisting field of active region NOAA 12529 in the Sun. IRIS data are complemented by full-disk observations of the Solar Dynamics Observatory satellite, relevant to the photosphere and the corona. The photospheric configuration of the EFR is also analyzed by measurements taken with the spectropolarimeter on board the Hinode satellite, when the EFR was fully developed. Recurrent intense brightenings that resemble UV bursts, with counterparts in all coronal passbands, are identified at the edges of the EFR. Jet activity is also observed at chromospheric and coronal levels, near the observed brightenings. The analysis of the IRIS line profiles reveals the heating of dense plasma in the low solar atmosphere and the driving of bidirectional high-velocity flows with speed up to 100 km s-1 at the same locations. Compared with previous observations and numerical models, these signatures suggest evidence of several long-lasting, small-scale magnetic reconnection episodes between the emerging bipole and the ambient field. This process leads to the cancellation of a preexisting photospheric flux concentration and appears to occur higher in the atmosphere than usually found in UV bursts, explaining the observed coronal counterparts. Title: A Si IV/O IV Electron Density Diagnostic for the Analysis of IRIS Solar Spectra Authors: Young, P. R.; Keenan, F. P.; Milligan, R. O.; Peter, H. Bibcode: 2018ApJ...857....5Y Altcode: 2018arXiv180301721Y Solar spectra of ultraviolet bursts and flare ribbons from the Interface Region Imaging Spectrograph (IRIS) have suggested high electron densities of > {10}12 cm-3 at transition region temperatures of 0.1 MK, based on large intensity ratios of Si IV λ1402.77 to O IV λ1401.16. In this work, a rare observation of the weak O IV λ1343.51 line is reported from an X-class flare that peaked at 21:41 UT on 2014 October 24. This line is used to develop a theoretical prediction of the Si IV λ1402.77 to O IV λ1401.16 ratio as a function of density that is recommended to be used in the high-density regime. The method makes use of new pressure-dependent ionization fractions that take account of the suppression of dielectronic recombination at high densities. It is applied to two sequences of flare kernel observations from the October 24 flare. The first shows densities that vary between 3× {10}12 and 3× {10}13 cm-3 over a seven-minute period, while the second location shows stable density values of around 2× {10}12 cm-3 over a three-minute period. Title: Element Abundance Ratios in the Quiet Sun Transition Region Authors: Young, P. R. Bibcode: 2018ApJ...855...15Y Altcode: 2018arXiv180105886Y Element abundance ratios of magnesium to neon (Mg/Ne) and neon to oxygen (Ne/O) in the transition region of the quiet Sun have been derived by re-assessing previously published data from the Coronal Diagnostic Spectrometer on board the Solar and Heliospheric Observatory in the light of new atomic data. The quiet Sun Mg/Ne ratio is important for assessing the effect of magnetic activity on the mechanism of the first ionization potential (FIP) effect, while the Ne/O ratio can be used to infer the solar photospheric abundance of neon, which cannot be measured directly. The average Mg/Ne ratio is found to be 0.52 ± 0.11, which applies over the temperature region 0.2-0.7 MK, and is consistent with the earlier study. The Ne/O ratio is, however, about 40% larger, taking the value 0.24 ± 0.05 that applies to the temperature range 0.08-0.40 MK. The increase is mostly due to changes in ionization and recombination rates that affect the equilibrium ionization balance. If the Ne/O ratio is interpreted as reflecting the photospheric ratio, then the photospheric neon abundance is 8.08 ± 0.09 or 8.15 ± 0.10 (on a logarithmic scale for which hydrogen is 12), according to whether the oxygen abundances of M. Asplund et al. or E. Caffau et al. are used. The updated photospheric neon abundance implies a Mg/Ne FIP bias for the quiet Sun of 1.6 ± 0.6. Title: Frequently Occurring Reconnection Jets from Sunspot Light Bridges Authors: Tian, Hui; Yurchyshyn, Vasyl; Peter, Hardi; Solanki, Sami K.; Young, Peter R.; Ni, Lei; Cao, Wenda; Ji, Kaifan; Zhu, Yingjie; Zhang, Jingwen; Samanta, Tanmoy; Song, Yongliang; He, Jiansen; Wang, Linghua; Chen, Yajie Bibcode: 2018ApJ...854...92T Altcode: 2018arXiv180106802T Solid evidence of magnetic reconnection is rarely reported within sunspots, the darkest regions with the strongest magnetic fields and lowest temperatures in the solar atmosphere. Using the world’s largest solar telescope, the 1.6 m Goode Solar Telescope, we detect prevalent reconnection through frequently occurring fine-scale jets in the Hα line wings at light bridges, the bright lanes that may divide the dark sunspot core into multiple parts. Many jets have an inverted Y-shape, shown by models to be typical of reconnection in a unipolar field environment. Simultaneous spectral imaging data from the Interface Region Imaging Spectrograph show that the reconnection drives bidirectional flows up to 200 km s-1, and that the weakly ionized plasma is heated by at least an order of magnitude up to ∼80,000 K. Such highly dynamic reconnection jets and efficient heating should be properly accounted for in future modeling efforts of sunspots. Our observations also reveal that the surge-like activity previously reported above light bridges in some chromospheric passbands such as the Hα core has two components: the ever-present short surges likely to be related to the upward leakage of magnetoacoustic waves from the photosphere, and the occasionally occurring long and fast surges that are obviously caused by the intermittent reconnection jets. Title: Modeling Coronal Response in Decaying Active Regions with Magnetic Flux Transport and Steady Heating Authors: Ugarte-Urra, Ignacio; Warren, Harry P.; Upton, Lisa A.; Young, Peter R. Bibcode: 2017ApJ...846..165U Altcode: 2017arXiv170804324U We present new measurements of the dependence of the extreme ultraviolet (EUV) radiance on the total magnetic flux in active regions as obtained from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Using observations of nine active regions tracked along different stages of evolution, we extend the known radiance—magnetic flux power-law relationship (I\propto {{{Φ }}}α ) to the AIA 335 Å passband, and the Fe xviii 93.93 Å spectral line in the 94 Å passband. We find that the total unsigned magnetic flux divided by the polarity separation ({{Φ }}/D) is a better indicator of radiance for the Fe xviii line with a slope of α =3.22+/- 0.03. We then use these results to test our current understanding of magnetic flux evolution and coronal heating. We use magnetograms from the simulated decay of these active regions produced by the Advective Flux Transport model as boundary conditions for potential extrapolations of the magnetic field in the corona. We then model the hydrodynamics of each individual field line with the Enthalpy-based Thermal Evolution of Loops model with steady heating scaled as the ratio of the average field strength and the length (\bar{B}/L) and render the Fe xviii and 335 Å emission. We find that steady heating is able to partially reproduce the magnitudes and slopes of the EUV radiance—magnetic flux relationships and discuss how impulsive heating can help reconcile the discrepancies. This study demonstrates that combined models of magnetic flux transport, magnetic topology, and heating can yield realistic estimates for the decay of active region radiances with time. Title: Compact solar UV burst triggered in a magnetic field with a fan-spine topology Authors: Chitta, L. P.; Peter, H.; Young, P. R.; Huang, Y. -M. Bibcode: 2017A&A...605A..49C Altcode: 2017arXiv170608059C Context. Solar ultraviolet (UV) bursts are small-scale features that exhibit intermittent brightenings that are thought to be due to magnetic reconnection. They are observed abundantly in the chromosphere and transition region, in particular in active regions.
Aims: We investigate in detail a UV burst related to a magnetic feature that is advected by the moat flow from a sunspot towards a pore. The moving feature is parasitic in that its magnetic polarity is opposite to that of the spot and the pore. This comparably simple photospheric magnetic field distribution allows for an unambiguous interpretation of the magnetic geometry leading to the onset of the observed UV burst.
Methods: We used UV spectroscopic and slit-jaw observations from the Interface Region Imaging Spectrograph (IRIS) to identify and study chromospheric and transition region spectral signatures of said UV burst. To investigate the magnetic topology surrounding the UV burst, we used a two-hour-long time sequence of simultaneous line-of-sight magnetograms from the Helioseismic and Magnetic Imager (HMI) and performed data-driven 3D magnetic field extrapolations by means of a magnetofrictional relaxation technique. We can connect UV burst signatures to the overlying extreme UV (EUV) coronal loops observed by the Atmospheric Imaging Assembly (AIA).
Results: The UV burst shows a variety of extremely broad line profiles indicating plasma flows in excess of ±200 km s-1 at times. The whole structure is divided into two spatially distinct zones of predominantly up- and downflows. The magnetic field extrapolations show a persistent fan-spine magnetic topology at the UV burst. The associated 3D magnetic null point exists at a height of about 500 km above the photosphere and evolves co-spatially with the observed UV burst. The EUV emission at the footpoints of coronal loops is correlated with the evolution of the underlying UV burst.
Conclusions: The magnetic field around the null point is sheared by photospheric motions, triggering magnetic reconnection that ultimately powers the observed UV burst and energises the overlying coronal loops. The location of the null point suggests that the burst is triggered low in the solar chromosphere.

Movies associated to Figs. 2 and 4 are available at http://www.aanda.org Title: Nonequilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind (Invited Review) Authors: Dudík, Jaroslav; Dzifčáková, Elena; Meyer-Vernet, Nicole; Del Zanna, Giulio; Young, Peter R.; Giunta, Alessandra; Sylwester, Barbara; Sylwester, Janusz; Oka, Mitsuo; Mason, Helen E.; Vocks, Christian; Matteini, Lorenzo; Krucker, Säm; Williams, David R.; Mackovjak, Šimon Bibcode: 2017SoPh..292..100D Altcode: 2017arXiv170603396D We review the presence and signatures of the non-equilibrium processes, both non-Maxwellian distributions and non-equilibrium ionization, in the solar transition region, corona, solar wind, and flares. Basic properties of the non-Maxwellian distributions are described together with their influence on the heat flux as well as on the rates of individual collisional processes and the resulting optically thin synthetic spectra. Constraints on the presence of high-energy electrons from observations are reviewed, including positive detection of non-Maxwellian distributions in the solar corona, transition region, flares, and wind. Occurrence of non-equilibrium ionization is reviewed as well, especially in connection to hydrodynamic and generalized collisional-radiative modeling. Predicted spectroscopic signatures of non-equilibrium ionization depending on the assumed plasma conditions are summarized. Finally, we discuss the future remote-sensing instrumentation that can be used for the detection of these non-equilibrium phenomena in various spectral ranges. Title: Constraints on Nonuniform Expansion in Coronal Loops Authors: Kucera, Therese A.; DeForest, Craig; Klimchuk, James A.; Young, Peter R. Bibcode: 2017SPD....4810608K Altcode: We use measurements of coronal loop properties to constrain the hypothesis that coronal loops expand differently in different directions. A long standing problem in understanding coronal loops is that although the magnetic field is expected to expand with altitude and does indeed seem to do so on scales of active regions, individual loops seem to have fairly uniform diameters along the length of the loop. Malanushenko & Schrijver (2013) have suggested that loops may be expanding, but with a non-circular cross section. In this scenario a loop might have a constant width in the plane of the sky, but expand along the line of sight. Furthermore, such loops might be easier to see from the point of view that does not show expansion. We use Hinode/EIS and SDO/AIA data to measure loop intensities, electron densities, temperatures and dimensions in order to determine the extent to which loops may be expanding along the line of sight. Title: Modeling Active Region Evolution - at the Sun’s Surface and into the Corona Authors: Upton, Lisa; Ugarte-Urra, Ignacio; Warren, Harry; Young, Peter R. Bibcode: 2017SPD....4840502U Altcode: The STEREO mission provides the first opportunity to track the long-term evolution of Active Regions over multiple rotations. The Advective Flux Transport (AFT) model is a state of the art Surface Flux Transport model, which simulates the observed near-surface flows to model the transport of magnetic flux over the entire Sun. Combining STEREO observations with AFT has allowed us to characterize the flux-luminosity relationship for He 304 Å and to validate the far-side evolution of individual active regions produced with AFT. Here, we present recent results in which we extend this radiance - magnetic flux power-law relationship to the AIA 335 Å passband, and the Fe XVIII 93.93 Å spectral line in the 94 Å passband. We use these results to test our current understanding of magnetic flux evolution and coronal heating by modeling the hydrodynamics of individual field lines with the Enthalpy-based Thermal Evolution of Loops (EBTEL) model including steady heating scaled as the ratio of the average field strength and the length (B/L). We find that steady heating is able to partially reproduce the EUV radiance - magnetic flux relationships and their observed temporal evolution. We also discuss how time-dependent heating may be able to explain the remaining discrepancies. This study demonstrates that combined models of magnetic flux transport, magnetic topology and heating can yield realistic estimates for the decay of active region radiances with time. Title: Observational Signatures of a Kink-unstable Coronal Flux Rope Using Hinode/EIS Authors: Snow, B.; Botha, G. J. J.; Régnier, S.; Morton, R. J.; Verwichte, E.; Young, P. R. Bibcode: 2017ApJ...842...16S Altcode: 2017arXiv170505114S The signatures of energy release and energy transport for a kink-unstable coronal flux rope are investigated via forward modeling. Synthetic intensity and Doppler maps are generated from a 3D numerical simulation. The CHIANTI database is used to compute intensities for three Hinode/EIS emission lines that cover the thermal range of the loop. The intensities and Doppler velocities at simulation-resolution are spatially degraded to the Hinode/EIS pixel size (1″), convolved using a Gaussian point-spread function (3″), and exposed for a characteristic time of 50 s. The synthetic images generated for rasters (moving slit) and sit-and-stare (stationary slit) are analyzed to find the signatures of the twisted flux and the associated instability. We find that there are several qualities of a kink-unstable coronal flux rope that can be detected observationally using Hinode/EIS, namely the growth of the loop radius, the increase in intensity toward the radial edge of the loop, and the Doppler velocity following an internal twisted magnetic field line. However, EIS cannot resolve the small, transient features present in the simulation, such as sites of small-scale reconnection (e.g., nanoflares). Title: The Electron Density in Explosive Transition Region Events Observed by IRIS Authors: Doschek, G. A.; Warren, H. P.; Young, P. R. Bibcode: 2016ApJ...832...77D Altcode: We discuss the intensity ratio of the O IV line at 1401.16 Å to the Si IV line at 1402.77 Å in Interface Region Imaging Spectrograph (IRIS) spectra. This intensity ratio is important if it can be used to measure high electron densities that cannot be measured using line intensity ratios of two different O IV lines from the multiplet within the IRIS wavelength range. Our discussion is in terms of considerably earlier observations made from the Skylab manned space station and other spectrometers on orbiting spacecraft. The earlier data on the O IV and Si IV ratio and other intersystem line ratios not available to IRIS are complementary to IRIS data. In this paper, we adopt a simple interpretation based on electron density. We adopt a set of assumptions and calculate the electron density as a function of velocity in the Si IV line profiles of two explosive events. At zero velocity the densities are about 2-3 × 1011 cm-3, and near 200 km s-1 outflow speed the densities are about 1012 cm-3. The densities increase with outflow speed up to about 150 km s-1 after which they level off. Because of the difference in the temperature of formation of the two lines and other possible effects such as non-ionization equilibrium, these density measurements do not have the precision that would be available if there were some additional lines near the formation temperature of O IV. Title: Exploring Coronal Dynamics: A Next Generation Solar Physics Mission white paper Authors: Morton, R. J.; Scullion, E.; Bloomfield, D. S.; McLaughlin, J. A.; Regnier, S.; McIntosh, S. W.; Tomczyk, S.; Young, P. Bibcode: 2016arXiv161106149M Altcode: Determining the mechanisms responsible for the heating of the coronal plasma and maintaining and accelerating the solar wind are long standing goals in solar physics. There is a clear need to constrain the energy, mass and momentum flux through the solar corona and advance our knowledge of the physical process contributing to these fluxes. Furthermore, the accurate forecasting of Space Weather conditions at the near-Earth environment and, more generally, the plasma conditions of the solar wind throughout the heliosphere, require detailed knowledge of these fluxes in the near-Sun corona. Here we present a short case for a space-based imaging-spectrometer coronagraph, which will have the ability to provide synoptic information on the coronal environment and provide strict constraints on the mass, energy, and momentum flux through the corona. The instrument would ideally achieve cadences of $\sim10$~s, spatial resolution of 1" and observe the corona out to 2~$R_{\sun}$. Such an instrument will enable significant progress in our understanding of MHD waves throughout complex plasmas, as well as potentially providing routine data products to aid Space Weather forecasting. Title: Solar Coronal Jets: Observations, Theory, and Modeling Authors: Raouafi, N. E.; Patsourakos, S.; Pariat, E.; Young, P. R.; Sterling, A. C.; Savcheva, A.; Shimojo, M.; Moreno-Insertis, F.; DeVore, C. R.; Archontis, V.; Török, T.; Mason, H.; Curdt, W.; Meyer, K.; Dalmasse, K.; Matsui, Y. Bibcode: 2016SSRv..201....1R Altcode: 2016arXiv160702108R; 2016SSRv..tmp...31R Coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of significant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of "nominal" solar flares and coronal mass ejections (CMEs), jets share many common properties with these phenomena, in particular, the explosive magnetically driven dynamics. Studies of jets could, therefore, provide critical insight for understanding the larger, more complex drivers of the solar activity. On the other side of the size-spectrum, the study of jets could also supply important clues on the physics of transients close or at the limit of the current spatial resolution such as spicules. Furthermore, jet phenomena may hint to basic process for heating the corona and accelerating the solar wind; consequently their study gives us the opportunity to attack a broad range of solar-heliospheric problems. Title: VizieR Online Data Catalog: NuGrid stellar data set I. Yields from H to Bi (Pignatari+, 2016) Authors: Pignatari, M.; Herwig, F.; Hirschi, R.; Bennett, M.; Rockefeller, G.; Fryer, C.; Timmes, F. X.; Ritter, C.; Heger, A.; Jones, S.; Battino, U.; Dotter, A.; Trappitsch, R.; Diehl, S.; Frischknecht, U.; Hungerford, A.; Magkotsios, G.; Travaglio, C.; Young, P. Bibcode: 2016yCat..22250024P Altcode: We provide a set of stellar evolution and nucleosynthesis calculations that applies established physics assumptions simultaneously to low- and intermediate-mass and massive star models. Our goal is to provide an internally consistent and comprehensive nuclear production and yield database for applications in areas such as presolar grain studies. Our non-rotating models assume convective boundary mixing (CBM) where it has been adopted before. We include 8 (12) initial masses for Z=0.01 (0.02). Models are followed either until the end of the asymptotic giant branch phase or the end of Si burning, complemented by simple analytic core-collapse supernova (SN) models with two options for fallback and shock velocities. The explosions show which pre-SN yields will most strongly be effected by the explosive nucleosynthesis. We discuss how these two explosion parameters impact the light elements and the s and p process. For low- and intermediate-mass models, our stellar yields from H to Bi include the effect of CBM at the He-intershell boundaries and the stellar evolution feedback of the mixing process that produces the 13C pocket. All post-processing nucleosynthesis calculations use the same nuclear reaction rate network and nuclear physics input. We provide a discussion of the nuclear production across the entire mass range organized by element group. The entirety of our stellar nucleosynthesis profile and time evolution output are available electronically, and tools to explore the data on the NuGrid VOspace hosted by the Canadian Astronomical Data Centre are introduced.

(12 data files). Title: Correlation of Coronal Plasma Properties and Solar Magnetic Field in a Decaying Active Region Authors: Ko, Yuan-Kuen; Young, Peter R.; Muglach, Karin; Warren, Harry P.; Ugarte-Urra, Ignacio Bibcode: 2016ApJ...826..126K Altcode: We present the analysis of a decaying active region observed by the EUV Imaging Spectrometer on Hinode during 2009 December 7-11. We investigated the temporal evolution of its structure exhibited by plasma at temperatures from 300,000 to 2.8 million degrees, and derived the electron density, differential emission measure, effective electron temperature, and elemental abundance ratios of Si/S and Fe/S (as a measure of the First Ionization Potential (FIP) Effect). We compared these coronal properties to the temporal evolution of the photospheric magnetic field strength obtained from the Solar and Heliospheric Observatory Michelson Doppler Imager magnetograms. We find that, while these coronal properties all decreased with time during this decay phase, the largest change was at plasma above 1.5 million degrees. The photospheric magnetic field strength also decreased with time but mainly for field strengths lower than about 70 Gauss. The effective electron temperature and the FIP bias seem to reach a “basal” state (at 1.5 × 106 K and 1.5, respectively) into the quiet Sun when the mean photospheric magnetic field (excluding all areas <10 G) weakened to below 35 G, while the electron density continued to decrease with the weakening field. These physical properties are all positively correlated with each other and the correlation is the strongest in the high-temperature plasma. Such correlation properties should be considered in the quest for our understanding of how the corona is heated. The variations in the elemental abundance should especially be considered together with the electron temperature and density. Title: Global Sausage Oscillation of Solar Flare Loops Detected by the Interface Region Imaging Spectrograph Authors: Tian, Hui; Young, Peter R.; Reeves, Katharine K.; Wang, Tongjiang; Antolin, Patrick; Chen, Bin; He, Jiansen Bibcode: 2016ApJ...823L..16T Altcode: 2016arXiv160501963T An observation from the Interface Region Imaging Spectrograph reveals coherent oscillations in the loops of an M1.6 flare on 2015 March 12. Both the intensity and Doppler shift of Fe xxi 1354.08 Å show clear oscillations with a period of ∼25 s. Remarkably similar oscillations were also detected in the soft X-ray flux recorded by the Geostationary Operational Environmental Satellites (GOES). With an estimated phase speed of ∼2420 km s-1 and a derived electron density of at least 5.4 × 1010 cm-3, the observed short-period oscillation is most likely the global fast sausage mode of a hot flare loop. We find a phase shift of ∼π/2 (1/4 period) between the Doppler shift oscillation and the intensity/GOES oscillations, which is consistent with a recent forward modeling study of the sausage mode. The observed oscillation requires a density contrast between the flare loop and coronal background of a factor ≥42. The estimated phase speed of the global mode provides a lower limit of the Alfvén speed outside the flare loop. We also find an increase of the oscillation period, which might be caused by the separation of the loop footpoints with time. Title: The CHIANTI atomic database Authors: Young, P. R.; Dere, K. P.; Landi, E.; Del Zanna, G.; Mason, H. E. Bibcode: 2016JPhB...49g4009Y Altcode: 2015arXiv151205620Y The freely available CHIANTI atomic database was first released in 1996 and has had a huge impact on the analysis and modeling of emissions from astrophysical plasmas. It contains data and software for modeling optically thin atom and positive ion emission from low density (≲1013 cm-3) plasmas from x-ray to infrared wavelengths. A key feature is that the data are assessed and regularly updated, with version 8 released in 2015. Atomic data for modeling the emissivities of 246 ions and neutrals are contained in CHIANTI, together with data for deriving the ionization fractions of all elements up to zinc. The different types of atomic data are summarized here and their formats discussed. Statistics on the impact of CHIANTI to the astrophysical community are given and examples of the diverse range of applications are presented. Title: A closer look at a coronal loop rooted in a sunspot umbra Authors: Chitta, L. P.; Peter, H.; Young, P. R. Bibcode: 2016A&A...587A..20C Altcode: 2015arXiv151203831C Context. Extreme UV (EUV) and X-ray loops in the solar corona connect regions of enhanced magnetic activity, but they are not usually rooted in the dark umbrae of sunspots because the strong magnetic field found there suppresses convection. This means that the Poynting flux of magnetic energy into the upper atmosphere is not significant within the umbra as long as there are no light bridges or umbral dots.
Aims: Here we report a rare observation of a coronal loop rooted in the dark umbra of a sunspot without any traces of light bridges or umbral dots. This allows us to investigate the loop without much confusion from background or line-of-sight integration effects.
Methods: We used the slit-jaw images and spectroscopic data from the Interface Region Imaging Spectrograph (IRIS) and concentrate on the line profiles of O iv and Si iv that show persistent strong redshifted components in the loop rooted in the umbra. Using the ratios of O iv, we can estimate the density and thus investigate the mass flux. The coronal context and temperature diagnostics of these observations is provided through the EUV channels of the Atmospheric Imaging Assembly (AIA).
Results: The coronal loop, embedded within cooler downflows, hosts supersonic downflows. The speed of more than 100 km s-1 is on the same order of magnitude in the transition region lines of O iv and Si iv, and is even seen at comparable speed in the chromospheric Mg II lines. At a projected distance of within 1'' of the footpoint, we see a shock transition to smaller downflow speeds of about 15 km s-1 being consistent with mass conservation across a stationary isothermal shock.
Conclusions: We see no direct evidence for energy input into the loop because the loop is rooted in the dark uniform part of the umbra with no light bridges or umbral dots near by. Thus one might conclude that we are seeing a siphon flow driven from the footpoint at the other end of the loop. However, for a final result data of similar quality at the other footpoint are needed, but this is too far away to be covered by the IRIS field of view. Title: Temporal Evolution of Chromospheric Evaporation: Case Studies of the M1.1 Flare on 2014 September 6 and X1.6 Flare on 2014 September 10 Authors: Tian, Hui; Young, Peter R.; Reeves, Katharine K.; Chen, Bin; Liu, Wei; McKillop, Sean Bibcode: 2015ApJ...811..139T Altcode: 2015arXiv150502736T With observations from the Interface Region Imaging Spectrograph, we track the complete evolution of ∼11 MK evaporation flows in an M1.1 flare on 2014 September 6 and an X1.6 flare on 2014 September 10. These hot flows, as indicated by the blueshifted Fe xxi 1354.08 Å line, evolve smoothly with a velocity decreasing exponentially from ∼200 km s-1 to almost stationary within a few minutes. We find a good correlation between the flow velocity and energy deposition rate as represented by the hard X-ray flux observed with the Reuven Ramaty High Energy Solar Spectroscopic Imager, or time derivative of the soft X-ray flux observed with the Geostationary Operational Environmental Satellites and the HINODE X-ray Telescope, which is in general agreement with models of nonthermal electron heating. The maximum blueshift of Fe xxi appears approximately at the same time as or slightly after the impulsive enhancement of the ultraviolet continuum and the Mg ii 2798.8 Å line emission, demonstrating that the evaporation flow is closely related to heating of the lower chromosphere. Finally, while the hot Fe xxi 1354.08 Å line is entirely blueshifted with no obvious rest component, cool chromospheric and transition region lines like Si iv 1402.77 Å are often not entirely redshifted but just reveal an obvious red wing enhancement at the ribbons, suggesting that the speed of chromospheric condensation might be larger than previously thought. Title: CHIANTI - An atomic database for emission lines. Version 8 Authors: Del Zanna, G.; Dere, K. P.; Young, P. R.; Landi, E.; Mason, H. E. Bibcode: 2015A&A...582A..56D Altcode: 2015arXiv150807631D We present version 8 of the CHIANTI database. This version includes a large amount of new data and ions, which represent a significant improvement in the soft X-ray, extreme UV (EUV) and UV spectral regions, which several space missions currently cover. New data for neutrals and low charge states are also added. The data are assessed, but to improve the modelling of low-temperature plasma the effective collision strengths for most of the new datasets are not spline-fitted as previously, but are retained as calculated. This required a change of the format of the CHIANTI electron excitation files. The format of the energy files has also been changed. Excitation rates between all the levels are retained for most of the new datasets, so the data can in principle be used to model high-density plasma. In addition, the method for computing the differential emission measure used in the CHIANTI software has been changed. Title: Report on the O IV and S IV lines observed by IRIS Authors: Young, Peter R. Bibcode: 2015arXiv150905011Y Altcode: The O IV intercombination lines observed by the Interface Region Imaging Spectrograph (IRIS) between 1397 and 1407 A provide useful density diagnostics. This document presents data that address two issues related to these lines: (1) the contribution of S IV to the O IV 1404.8 line; and (2) the range of sensitivity of the O IV 1399.8/1401.2 ratio. Title: The Fast Filament Eruption Leading to the X-flare on 2014 March 29 Authors: Kleint, Lucia; Battaglia, Marina; Reardon, Kevin; Sainz Dalda, Alberto; Young, Peter R.; Krucker, Säm Bibcode: 2015ApJ...806....9K Altcode: 2015arXiv150400515K We investigate the sequence of events leading to the solar X1 flare SOL2014-03-29T17:48. Because of the unprecedented joint observations of an X-flare with the ground-based Dunn Solar Telescope and the spacecraft IRIS, Hinode, RHESSI, STEREO, and the Solar Dynamics Observatory, we can sample many solar layers from the photosphere to the corona. A filament eruption was observed above a region of previous flux emergence, which possibly led to a change in magnetic field configuration, causing the X-flare. This was concluded from the timing and location of the hard X-ray emission, which started to increase slightly less than a minute after the filament accelerated. The filament showed Doppler velocities of ∼2-5 km s-1 at chromospheric temperatures for at least one hour before the flare occurred, mostly blueshifts, but also redshifts near its footpoints. Fifteen minutes before the flare, its chromospheric Doppler shifts increased to ∼6-10 km s-1 and plasma heating could be observed before it lifted off with at least 600 km s-1 as seen in IRIS data. Compared to previous studies, this acceleration (∼3-5 km s-2) is very fast, while the velocities are in the common range for coronal mass ejections. An interesting feature was a low-lying twisted second filament near the erupting filament, which did not seem to participate in the eruption. After the flare ribbons started on each of the second filament’s sides, it seems to have untangled and vanished during the flare. These observations are some of the highest resolution data of an X-class flare to date and reveal some small-scale features yet to be explained. Title: Measuring Elemental Abundances in Impulsive Heating Events with EIS Authors: Warren, Harry; Doschek, George A.; Young, Peter Bibcode: 2015TESS....121306W Altcode: It is well established that elemental abundances vary in the solar atmosphere and that this variation is organized by first ionization potential (FIP). Previous studies have indicated that in the solar corona low FIP elements, such as Fe, Si, and Mg, are enriched relative to high FIP elements, such as H, He, C, N, and O. In this paper we report on measurements of plasma composition made during transient heating events observed at transition region temperatures with the Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode. During these events the intensities of O IV, V, and VI emission lines are enhanced relative to emission lines from Mg V, VI, and VII and indicate a composition close to that of the photosphere. Differential emission measure calculations show a broad distribution of temperatures in these events. Long-lived coronal structures, in contrast, show an enrichment of low FIP elements and relatively narrow temperature distributions. We conjecture that plasma composition is an important signature of the coronal heating process, with impulsive heating leading to the evaporation of unfractionated material from the lower layers of the solar atmosphere and higher frequency heating leading to the accumulation of low-FIP elements in the corona. Title: Dark Jets in Solar Coronal Holes Authors: Young, Peter R. Bibcode: 2015ApJ...801..124Y Altcode: 2015arXiv150102751Y A new solar feature termed a dark jet is identified from observations of an extended solar coronal hole that was continuously monitored for over 44 hr by the Extreme Ultraviolet Imaging Spectrometer on board the Hinode spacecraft in 2011 February 8-10 as part of Hinode Operation Plan No. 177 (HOP 177). Line of sight (LOS) velocity maps derived from the coronal Fe xii λ195.12 emission line, formed at 1.5 MK, revealed a number of large-scale, jet-like structures that showed significant blueshifts. The structures had either weak or no intensity signal in 193 Å filter images from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, suggesting that the jets are essentially invisible to imaging instruments. The dark jets are rooted in bright points and occur both within the coronal hole and at the quiet Sun-coronal hole boundary. They exhibit a wide range of shapes, from narrow columns to fan-shaped structures, and sometimes multiple jets are seen close together. A detailed study of one dark jet showed LOS speeds increasing along the jet axis from 52 to 107 km s-1 and a temperature of 1.2-1.3 MK. The low intensity of the jet was due either to a small filling factor of 2% or to a curtain-like morphology. From the HOP 177 sample, dark jets are as common as regular coronal hole jets, but their low intensity suggests a mass flux around two orders of magnitude lower. Title: Piezoelectric Dust Detector Design and Calibration for the Armadillo Program Authors: Odom, F.; Richter, G.; Brown, J.; Martinsen, B.; Cai, R.; Fellows, M.; Wolf, A.; Montag, C.; Young, P.; Carmona-Reyes, J. A.; Schmoke, J.; Cook, M.; Garner, B.; Gravagne, I.; Pin, K.; Shedd, L.; Groskreutz, T.; Hegle, T.; Mulenos, N.; Stone, J.; Wiley, C.; Yanga, V.; Eustice, D.; Flachsbart, K.; Steele, N.; Tilley, C.; Friudenberg, P.; Penshorn, D.; Henderson, L.; Cavazos, E.; Nabili, A.; Cox, E.; Cox, A.; Wood, J.; Devine, L.; Curran, J.; Mendiola, A.; Falkner, C.; Laufer, R.; Srama, R.; Schubert, K. E.; Matthews, L. S.; Lightsey, G.; Hyde, T. W. Bibcode: 2015LPI....46.2191O Altcode: 2015LPICo1832.2191O Design and calibration of piezoelectric dust detector for LEO. Title: The 2014 March 29 X-flare: Subarcsecond Resolution Observations of Fe XXI λ1354.1 Authors: Young, Peter R.; Tian, Hui; Jaeggli, Sarah Bibcode: 2015ApJ...799..218Y Altcode: 2014arXiv1409.8603Y The Interface Region Imaging Spectrometer (IRIS) is the first solar instrument to observe ~10 MK plasma at subarcsecond spatial resolution through imaging spectroscopy of the Fe XXI λ1354.1 forbidden line. IRIS observations of the X1 class flare that occurred on 2014 March 29 at 17:48 UT reveal Fe XXI emission from both the flare ribbons and the post-flare loop arcade. Fe XXI appears at all of the chromospheric ribbon sites, although typically with a delay of one raster (75 s) and sometimes offset by up to 1''. 100-200 km s-1 blue-shifts are found at the brightest ribbons, suggesting hot plasma upflow into the corona. The Fe XXI ribbon emission is compact with a spatial extent of <2'', and can extend beyond the chromospheric ribbon locations. Examples are found of both decreasing and increasing blue-shift in the direction away from the ribbon locations, and blue-shifts were present for at least six minutes after the flare peak. The post-flare loop arcade, seen in Atmospheric Imaging Assembly 131 Å filtergram images that are dominated by Fe XXI, exhibited bright loop-tops with an asymmetric intensity distribution. The sizes of the loop-tops are resolved by IRIS at >=1'', and line widths in the loop-tops are not broader than in the loop-legs suggesting the loop-tops are not sites of enhanced turbulence. Line-of-sight speeds in the loop arcade are typically <10 km s-1, and mean non-thermal motions fall from 43 km s-1 at the flare peak to 26 km s-1 six minutes later. If the average velocity in the loop arcade is assumed to be at rest, then it implies a new reference wavelength for the Fe XXI line of 1354.106 ± 0.023 Å. Title: A coronal hole jet observed with Hinode and the Solar Dynamics Observatory Authors: Young, Peter R.; Muglach, Karin Bibcode: 2014PASJ...66S..12Y Altcode: 2014PASJ..tmp..106Y; 2014arXiv1402.4389Y; 2014PASJ...66..S12Y A small blowout jet was observed at the boundary of the south polar coronal hole on 2011 February 8 at around 21:00 UT. Images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) revealed an expanding loop rising from one footpoint of a compact, bipolar bright point. Magnetograms from the Helioseismic Magnetic Imager (HMI) on board SDO showed that the jet was triggered by the cancelation of a parasitic positive polarity feature near the negative pole of the bright point. The jet emission was present for 25 min and it extended 30 Mm from the bright point. Spectra from the Extreme Ultraviolet Imaging Spectrometer on board Hinode yielded a temperature and density of 1.6 MK and 0.9-1.7 × 108 cm-3 for the ejected plasma. Line-of-sight velocities reached up to 250 km s-1 and were found to increase with height, suggesting plasma acceleration within the body of the jet. Evidence was found for twisting motions within the jet based on variations of the line-of-sight velocities across the jet width. The derived angular speed was in the range (9-12) × 10-3 rad s-1, consistent with previous measurements from jets. The density of the bright point was 7.6 × 108 cm-3, and the peak of the bright point's emission measure occurred at 1.3 MK, with no plasma above 3 MK. Title: The VAULT2.0 Observing Campaign: A Comprehensive Investigation of the Chromosphere-Corona Interface at Sub-arcsecond scales Authors: Vourlidas, A.; Korendyke, C.; Tun-Beltran, S. D.; Ugarte-Urra, I.; Morrill, J. S.; Warren, H. P.; Young, P.; De Pontieu, B.; Gauzzi, G.; Reardon, K. Bibcode: 2014AGUFMSH41C4155V Altcode: We report the first results from an observing campaign in support of the VAULT2.0 sounding rocket launch on September 30, 2014. VAULT2.0 is a Lya (1216Å) spectroheliograph capable of 0.3" (~250 km) spatial resolution. The objective of the VAULT2.0 project is the study of the chromosphere-corona interface. This interface has acquired renewed emphasis over the last few years, thanks to high-resolution observations from Hinode/SOT and EIS instruments and the Lya imaging from the two VAULT flights. The observations have shown that the upper chromosphere may play a more important role in heating the corona and in affecting EUV observations that previously thought: (1) by supplying the mass via Type-II spicules and, (2) by absorbing coronal emission. Many of the required clues for further progress are located in sub-arcsecond structures with temperatures between 10000 and 50000 K, a regime not accessible by Hinode or SDO. Lyman-alpha observations are, therefore, ideal, for filling in this gap. The observing campaign in support of the VAULT2.0 is closely coordinated with the Hinode and IRIS missions to study the mass/energy flow from the chromosphere to the corona with joint observations of type-II spicules, and the magnetic connectivity of coronal loops using the full imaging and spectral capabilities of IRIS, Hinode and SDO. Several ground-based observatories also provide important observations (IBIS, BBSO, SOLIS). The VAULT2.0 project is funded by the NASA LCAS program. Title: The 2014 March 29 X-Flare: Results from the Best-Ever Flare Observation Authors: Young, P. Bibcode: 2014AGUFMSH53D..01Y Altcode: An X1 class solar flare occurred on 2014 March 29, peaking at 17:48 UT, and producing a filament eruption and EUV wave. It was observed as part of a Sac Peak-IRIS-Hinode observing program, delivering unprecedented coverage at all layers of the solar atmosphere. This talk will summarize new results obtained for this flare, with a particular focus on spectroscopic results obtained from IRIS and Hinode/EIS. Topics include mass flows prior and during the filament eruption, dynamics of 10 MK plasma during the flare rise phase, and the evolution of the flare ribbons Title: Solar Dynamics Observatory and Hinode Observations of a Blowout Jet in a Coronal Hole Authors: Young, P. R.; Muglach, K. Bibcode: 2014SoPh..289.3313Y Altcode: 2013arXiv1309.7324Y; 2014SoPh..tmp...24Y A blowout jet occurred within the south coronal hole on 9 February 2011 at 09:00 UT and was observed by the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory, and by the EUV Imaging Spectrometer (EIS) and X-Ray Telescope (XRT) onboard the Hinode spacecraft during coronal-hole monitoring performed as part of Hinode Operations Program No. 177. Images from AIA show expanding hot and cold loops from a small bright point with plasma ejected in a curtain up to 30 Mm wide. The initial intensity front of the jet had a projected velocity of 200 km s−1, and the line-of-sight (LOS) velocities measured by EIS are between 100 and 250 km s−1. The LOS velocities increased along the jet, implying that an acceleration mechanism operates within the body of the jet. The jet plasma had a density of 2.7×108 cm−3 and a temperature of 1.4 MK. During the event a number of bright kernels were seen at the base of the bright point. The kernels have sizes of ≈ 1000 km, are variable in brightness, and have lifetimes of 1 - 15 minutes. An XRT filter ratio yields temperatures of 1.5 - 3.0 MK for the kernels. The bright point existed for at least ten hours, but disappeared within two hours after the jet, which lasted for 30 minutes. HMI data reveal converging photospheric flows at the location of the bright point, and the mixed-polarity magnetic flux canceled over a period of four hours on either side of the jet. Title: Intense active region brightenings observed by IRIS Authors: Young, Peter R. Bibcode: 2014AAS...22430202Y Altcode: Active region raster scans obtained with the Interface Region Imaging Spectrometer (IRIS) typically reveal a few extremely intense brightenings in the Si IV emission lines (formed around 80,000 K) that are not related to flares. The brightenings are around 0.5-1.0 arcsec (0.4-0.8 Mm) in size, and the line profiles can be very broad (up to 300 km/s), showing multiple emission components. Similar brightenings were reported from the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO) and were termed active region blinkers. The much higher spatial and spectral resolution of IRIS together with high cadence coronal and photospheric imaging from the Solar Dynamics Observatory allows the brightenings to be identified with magnetic field and coronal signatures. Example events will be shown and statistics given. Title: Temporal Evolution of Solar Wind Ion Composition and their Source Coronal Holes During the Declining Phase of Cycle 23 Authors: Ko, Yuan-Kuen; Muglach, Karin; Wang, Yi-Ming; Young, Peter R.; Lepri, Susan T. Bibcode: 2014AAS...22432366K Altcode: We present our analysis of the temporal trend in the solar wind (SW) ion charge states and the properties in the associated source coronal holes (CHs) during the declining phase of solar cycle 23. We find that the SW ions exhibit a trend of decreasing ionization state with time, consistent with previous studies. However the rate of decrease is different between the slow and fast SW. The photospheric magnetic field strength in both regions is found to exhibit similar trend of decrease with time. On the other hand, the temporal trend is different in the line emissions from different layers of the atmosphere (chromosphere, transit region and corona). Within each CH, the coronal emission generally increases toward the boundary of the CH as the underlying photospheric magnetic field strength increases, the net unbalanced field strength decreases and the magnetic field becomes less unipolar. But the coronal emission averaged over the entire CH area does not have appreciable change with time. We find that ions which freeze-in at lower altitude in the corona, such as C and O ions, have a stronger correlation between their ionization state and the average photospheric magnetic field strength in the slow SW, while Fe ions which freeze-in at higher altitude have a stronger correlation in the fast SW. Our analyses provide important clues for how the SW is formed, heated and accelerated in response to the long-term evolution of the solar magnetic field at its source coronal hole. Title: Temporal Evolution of Solar Wind Ion Composition and their Source Coronal Holes during the Declining Phase of Cycle 23. I. Low-latitude Extension of Polar Coronal Holes Authors: Ko, Yuan-Kuen; Muglach, Karin; Wang, Yi-Ming; Young, Peter R.; Lepri, Susan T. Bibcode: 2014ApJ...787..121K Altcode: We analyzed 27 solar wind (SW) intervals during the declining phase of cycle 23, whose source coronal holes (CHs) can be unambiguously identified and are associated with one of the polar CHs. We found that the SW ions have a temporal trend of decreasing ionization state, and such a trend is different between the slow and fast SW. The photospheric magnetic field, both inside and at the outside boundary of the CH, also exhibits a trend of decrease with time. However, EUV line emissions from different layers of the atmosphere exhibit different temporal trends. The coronal emission inside the CH generally increases toward the CH boundary as the underlying field increases in strength and becomes less unipolar. In contrast, this relationship is not seen in the coronal emission averaged over the entire CH. For C and O SW ions that freeze-in at lower altitude, stronger correlation between their ionization states and field strength (both signed and unsigned) appears in the slow SW, while for Fe ions that freeze-in at higher altitude, stronger correlation appears in the fast SW. Such correlations are seen both inside the CH and at its boundary region. On the other hand, the coronal electron temperature correlates well with the SW ion composition only in the boundary region. Our analyses, although not able to determine the likely footpoint locations of the SW of different speeds, raise many outstanding questions for how the SW is heated and accelerated in response to the long-term evolution of the solar magnetic field. Title: Photospheric Signatures of Coronal Hole Jets Authors: Muglach, Karin; Young, Peter R. Bibcode: 2014AAS...22432333M Altcode: Coronal jets are transient, collimated ejections of plasma that are a common feature of solar X-ray and EUV image sequences. Of special interest is the contribution that coronal hole jets make to the solar wind outflow. A new class of coronal hole jets, termed "dark jets", has been identified with the EUV Imaging Spectrometer (EIS) on board Hinode. The jets are identified in EUV spectral lines with line-of-sight velocities of 50-100 km/s and enhanced line widths, yet they show little or no intensity signature in image sequences from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO) or the X-Ray Telescope on board Hinode.In this contribution we will investigate the photosphere at the footpoint of these jets. White light images from the Helioseismic Magnetic Imager (HMI) on board SDO are used to derive the plane-of-sky flow field using local correlation tracking, and HMI magnetograms show the evolution of the magnetic flux. Both the evolution of the magnetic field and flows allow us to study the photospheric driver of these jets. Title: Assessing atomic data accuracy along isoelectronic sequences Authors: Young, Peter R.; Feldman, Uri Bibcode: 2014AAS...22410603Y Altcode: The CHIANTI atomic database provides radiative decay rates and electron excitation rates for modeling collisionally-excited emission lines from 242 ions. We present a new method for assessing atomic data accuracy whereby level populations for specific atomic levels are plotted along isoelectronic sequences. Results are presented for the helium through fluorine isoelectronic sequences. Generally a smooth variation of population with atomic number is found and so anomalies, often due to problems with atomic data, can be identified. One exception is for the iron ions, which can show level populations an order of magnitude larger than neighboring ions. These can be demonstrated to be due to the much larger atomic models that are typically run for iron ions. Title: Core and Wing Densities of Asymmetric Coronal Spectral Profiles: Implications for the Mass Supply of the Solar Corona Authors: Patsourakos, S.; Klimchuk, J. A.; Young, P. R. Bibcode: 2014ApJ...781...58P Altcode: 2013arXiv1312.4842P Recent solar spectroscopic observations have shown that coronal spectral lines can exhibit asymmetric profiles, with enhanced emissions at their blue wings. These asymmetries correspond to rapidly upflowing plasmas at speeds exceeding ≈50 km s-1. Here, we perform a study of the density of the rapidly upflowing material and compare it with that of the line core that corresponds to the bulk of the plasma. For this task, we use spectroscopic observations of several active regions taken by the Extreme Ultraviolet Imaging Spectrometer of the Hinode mission. The density sensitive ratio of the Fe XIV lines at 264.78 and 274.20 Å is used to determine wing and core densities. We compute the ratio of the blue wing density to the core density and find that most values are of order unity. This is consistent with the predictions for coronal nanoflares if most of the observed coronal mass is supplied by chromospheric evaporation driven by the nanoflares. However, much larger blue wing-to-core density ratios are predicted if most of the coronal mass is supplied by heated material ejected with type II spicules. Our measurements do not rule out a spicule origin for the blue wing emission, but they argue against spicules being a primary source of the hot plasma in the corona. We note that only about 40% of the pixels where line blends could be safely ignored have blue wing asymmetries in both Fe XIV lines. Anticipated sub-arcsecond spatial resolution spectroscopic observations in future missions could shed more light on the origin of blue, red, and mixed asymmetries. Title: Evidence for Two Separate Heliospheric Current Sheets of Cylindrical Shape During Mid-2012 Authors: Wang, Y. -M.; Young, P. R.; Muglach, K. Bibcode: 2014ApJ...780..103W Altcode: During the reversal of the Sun's polar fields at sunspot maximum, outward extrapolations of magnetograph measurements often predict the presence of two or more current sheets extending into the interplanetary medium, instead of the single heliospheric current sheet (HCS) that forms the basis of the standard "ballerina skirt" picture. By comparing potential-field source-surface models of the coronal streamer belt with white-light coronagraph observations, we deduce that the HCS was split into two distinct structures with circular cross sections during mid-2012. These cylindrical current sheets were centered near the heliographic equator and separated in longitude by roughly 180° a corresponding four-sector polarity pattern was observed at Earth. Each cylinder enclosed a negative-polarity coronal hole that was identifiable in extreme ultraviolet images and gave rise to a high-speed stream. The two current sheet systems are shown to be a result of the dominance of the Sun's nonaxisymmetric quadrupole component, as the axial dipole field was undergoing its reversal during solar cycle 24. Title: Major updates to the CHIANTI atomic database for the astronomy community Authors: Young, Peter Bibcode: 2014adap.prop...38Y Altcode: CHIANTI is a critically-assessed, freely-available atomic database and software package that is widely-used for the interpretation and analysis of astronomical data. A three-year project is proposed to modernize the CHIANTI infrastructure (software code and methods, and data formats), include new atomic data and processes, add new software capability and write new documentation. These improvements will provide more accurate atomic data and new capabilities specifically for the astrophysics community, enabling new and expanded analyzes of data from NASA-supported missions that will directly address some of the most important NASA science goals: exploring galaxy evolution, understanding the nature of black holes, and determining the origins of stars. High quality atomic data are fundamental to all aspects of astrophysics, and the accuracy of the assessed atomic data in CHIANTI is recognized by the makers of other astrophysics plasma codes, including CLOUDY, APED, XSTAR and MOCASSIN who incorporate the data into their models. The proposed CHIANTI updates therefore indirectly benefit many other astronomers. The specific enhancements that will be made are: 1. a new method for assessing and storing electron excitation that will give improved accuracy at low temperatures suitable for photoionized plasmas; 2. faster software calculations and data reading necessary to include larger (1000's of levels) atomic models; 3. modernize aging IDL code, aligning it with the newer Python code; 4. add new atomic data for the iron peak elements, forbidden lines, and key isoelectronic sequences; 5. perform and publish the first ever benchmark study of visible and ultraviolet forbidden line diagnostics; 6. greatly expand recombination line models for X-ray applications; 7. interface the database to a state-of-the-art emission line fitting package; and 8. create new technical documentation describing all aspects of the database. Title: Progress toward high resolution EUV spectroscopy Authors: Korendyke, C.; Doschek, G. A.; Warren, H.; Young, P. R.; Chua, D.; Hassler, D. M.; Landi, E.; Davila, J. M.; Klimchuck, J.; Tun, S.; DeForest, C.; Mariska, J. T.; Solar C Spectroscopy Working Group; LEMUR; EUVST Development Team Bibcode: 2013SPD....44..143K Altcode: HIgh resolution EUV spectroscopy is a critical instrumental technique to understand fundamental physical processes in the high temperature solar atmosphere. Spectroscopic observations are used to measure differential emission measure, line of sight and turbulent flows, plasma densities and emission measures. Spatially resolved, spectra of these emission lines with adequate cadence will provide the necessary clues linking small scale structures with large scale, energetic solar phenomena. The necessary observations to determine underlying physical processes and to provide comprehensive temperature coverage of the solar atmosphere above the chromosphere will be obtained by the proposed EUVST instrument for Solar C. This instrument and its design will be discussed in this paper. Progress on the VEry high Resolution Imaging Spectrograph (VERIS) sounding rocket instrument presently under development at the Naval Research Laboratory will also be discussed. Title: A Spectroscopic Survey of Coronal Hole Jets Authors: Young, Peter R.; Muglach, K. Bibcode: 2013SPD....44...19Y Altcode: Coronal hole jets have been suggested to make a significant contribution to the solar wind, but spectroscopic measurements - which provide the best means of measuring the mass flux - have been rare due to the difficulty of capturing jets with narrow slit spectrometers. A continuous two day coronal hole measurement made with the Hinode/EIS instrument is reported, which has revealed over 30 jets seen in the coronal Fe XII 195.12 (1.5 MK) emission line. More than half of the events have no clear signature in SDO/AIA or Hinode/XRT images and thus represent a separate class of jet events not previously reported. The jets show a wide range of morphologies, ranging from classic columnar features to mini-CME events. Statistics of the events will be presented: their relation to bright points and the coronal hole boundary; durations; and repeated occurrence. Velocity, density and temperature measurements derived from the EIS spectra will be presented, and mass flux estimated. The photospheric signatures of the jets, as determined from SDO/HMI, will be shown in a separate presentation (Muglach & Young). Title: Photospheric signatures of coronal hole jets Authors: Muglach, Karin; Young, P. R. Bibcode: 2013SPD....44...20M Altcode: Jets in EUV and X-ray images have been observed for several decades. Many of them originate in coronal holes which have received special interest as possible contributors to the solar wind. A new class of CH jets are observed with Hinode/EIS which show pronounced signatures in EUV spectral lines. Coronal velocities of up to 200 km/s and enhancements in line width are measured. On the other hand these jets are hardly visible in imaging data like SDO/AIA and Hinode/XRT (see contribution by Young and Muglach). In this contribution we will investigate the photospheric signatures at the footpoint of these jets. We use SDO/HMI magnetograms to show the evolution of the magnetic flux. From SDO white light images we derive the plane-of-sky flow field using local correlation tracking. Both the evolution of the magnetic field and the flows allow us to study the photospheric drivers of these jets. Title: Properties of a Solar Flare Kernel Observed by Hinode and SDO Authors: Young, P. R.; Doschek, G. A.; Warren, H. P.; Hara, H. Bibcode: 2013ApJ...766..127Y Altcode: 2012arXiv1212.4388Y Flare kernels are compact features located in the solar chromosphere that are the sites of rapid heating and plasma upflow during the rise phase of flares. An example is presented from a M1.1 class flare in active region AR 11158 observed on 2011 February 16 07:44 UT for which the location of the upflow region seen by EUV Imaging Spectrometer (EIS) can be precisely aligned to high spatial resolution images obtained by the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO). A string of bright flare kernels is found to be aligned with a ridge of strong magnetic field, and one kernel site is highlighted for which an upflow speed of ≈400 km s-1 is measured in lines formed at 10-30 MK. The line-of-sight magnetic field strength at this location is ≈1000 G. Emission over a continuous range of temperatures down to the chromosphere is found, and the kernels have a similar morphology at all temperatures and are spatially coincident with sizes at the resolution limit of the AIA instrument (lsim400 km). For temperatures of 0.3-3.0 MK the EIS emission lines show multiple velocity components, with the dominant component becoming more blueshifted with temperature from a redshift of 35 km s-1 at 0.3 MK to a blueshift of 60 km s-1 at 3.0 MK. Emission lines from 1.5-3.0 MK show a weak redshifted component at around 60-70 km s-1 implying multi-directional flows at the kernel site. Significant non-thermal broadening corresponding to velocities of ≈120 km s-1 is found at 10-30 MK, and the electron density in the kernel, measured at 2 MK, is 3.4 × 1010 cm-3. Finally, the Fe XXIV λ192.03/λ255.11 ratio suggests that the EIS calibration has changed since launch, with the long wavelength channel less sensitive than the short wavelength channel by around a factor two. Title: Chromospheric Evaporation in an M1.8 Flare Observed by the Extreme-ultraviolet Imaging Spectrometer on Hinode Authors: Doschek, G. A.; Warren, H. P.; Young, P. R. Bibcode: 2013ApJ...767...55D Altcode: 2012arXiv1212.4027D We discuss observations of chromospheric evaporation for a complex flare that occurred on 2012 March 9 near 03:30 UT obtained from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft. This was a multiple event with a strong energy input that reached the M1.8 class when observed by EIS. EIS was in raster mode and fortunately the slit was almost at the exact location of a significant energy input. Also, EIS obtained a full-CCD spectrum of the flare, i.e., the entire CCD was readout so that data were obtained for about the 500 lines identified in the EIS wavelength ranges. Chromospheric evaporation characterized by 150-200 km s-1 upflows was observed in multiple locations in multi-million degree spectral lines of flare ions such as Fe XXII, Fe XXIII, and Fe XXIV, with simultaneous 20-60 km s-1 upflows in million degree coronal lines from ions such as Fe XII-Fe XVI. The behavior of cooler, transition region ions such as O VI, Fe VIII, He II, and Fe X is more complex, but upflows were also observed in Fe VIII and Fe X lines. At a point close to strong energy input in space and time, the flare ions Fe XXII, Fe XXIII, and Fe XXIV reveal an isothermal source with a temperature close to 14 MK and no strong blueshifted components. At this location there is a strong downflow in cooler active region lines from ions such as Fe XIII and Fe XIV, on the order of 200 km s-1. We speculate that this downflow may be evidence of the downward shock produced by reconnection in the current sheet seen in MHD simulations. A sunquake also occurred near this location. Electron densities were obtained from density sensitive lines ratios from Fe XIII and Fe XIV. Atmospheric Imaging Assembly (AIA) observations from the Solar Dynamics Observatory are used with JHelioviewer to obtain a qualitative overview of the flare. However, AIA data are not presented in this paper. In summary, spectroscopic data from EIS are presented that can be used for predictive tests of models of chromospheric evaporation as envisaged in the Standard Flare Model. Title: Flare Footpoint Regions Observed by the Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode Authors: Doschek, G. A.; Warren, H. P.; Young, P. R.; Caspi, A. Bibcode: 2013enss.confE..74D Altcode: The Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode has observed flare footpoints using a variety of studies designed to observe various aspects of the solar flare Standard Model. Some of these observations are accompanied by imaging data from RHESSI. We present observations of upflows in flare footpoint regions obtained from picket-fence raster observations of two flares that occurred on 24 and 25 September 2011. The observations consist of upflow and non-thermal speeds at various temperatures (from about 1 MK to 15 MK) at footpoint regions as well as a limited differential emission measure. RHESSI observations provide constraints on the energetic electron precipitation into the footpoints. Electron densities are available from an Fe XIV ratio, and SDO AIA data are also investigated for context. The RHESSI energy input will be assessed in terms of 1D models of the footpoint regions. Title: CHIANTI 7.1: a new database release for SDO data analysis Authors: Young, P. R.; Landi, E.; Del Zanna, G.; Dere, K. P.; Mason, H. E. Bibcode: 2013enss.confE..58Y Altcode: Version 7.1 of the CHIANTI atomic database was released in October 2012 and contains a number of improvements to better model data returned by the AIA and EVE instruments on board SDO. Specifically the models for the important iron ions Fe VIII to Fe XIV have been greatly expanded, yielding many thousands of new transitions in the 50-170 angstrom range that enable the irradiance spectra obtained by EVE to be modeled more accurately. A lack of available atomic data meant that the AIA 94 angstrom channel was not well modeled at low temperatures in earlier versions of CHIANTI. New data for Fe VIII, Fe X and Fe XIV added to CHIANTI 7.1 give important contributions to the channel and greatly improve comparisons with theory. Title: SDO and Hinode observations of coronal heating at a flare kernel site Authors: Young, P. R.; Doschek, G. A.; Warren, H. P.; Hara, H. Bibcode: 2013enss.confE..36Y Altcode: Flare kernels are compact features located in the chromosphere that are the sites of rapid heating and plasma upflow during the rise phase of flares. They provide an excellent opportunity for testing models of energy transport and dissipation in the solar atmosphere as they are very bright and emit over a wide temperature range. A M1.1 class flare that peaked at 07:44 UT on 2011 February 16 was observed simultaneously by SDO and Hinode, and one flare kernel observed prior to the flare peak is highlighted. It is found to emit at all temperatures from the chromosphere through to 30 MK, with all AIA channels brightening simultaneously and rise times of only 1 minute. The kernel is located on a ridge of strong magnetic field close to a neutral line in the active region. The kernel is at the resolution limit of AIA, suggesting a size of < 0.6 arcsec. Hinode/EIS allows velocity patterns in the kernel to be tracked over a wide temperature range and reveals a dominant high speed upflow of 400 km/s at temperatures of 10-30 MK, with both down and upflows measured at cooler temperatures of 1.5-3.0 MK, suggesting unresolved structures. All emission lines show evidence of significant non-thermal broadening, and the electron density of the plasma is 3.4 x 10^10 cm-3. The observations are compared to models of chromospheric evaporation and similarities and differences are highlighted. Title: The velocity signature of coronal jets as observed with Hinode/EIS Authors: Muglach, K.; Young, P. R. Bibcode: 2013enss.confE..59M Altcode: In this contribution we show preliminary results of a study of jets in coronal holes. We use Hinode/EIS to investigate the spectroscopic signatures of the jets and SDO/AIA and HMI to derive additional information on the plasma and magnetic field evolution. EIS was scanning a low latitude coronal hole and tracking it for about 2 days as it rotated over the solar disk. The coronal jets are best revealed through Doppler and line width maps of Fe XII 195.1 A (formed at 1.5 MK), and have sizes of 10-100 arcsec. Higher spatial and time resolution is provided by SDO: coronal and chromospheric images from AIA show the time evolution of the jet and line-of-sight magnetograms show the evolution of the magnetic footpoints of the jet. We present several examples of these extended jets and describe their properties as derived from the diagnostics we have available. Title: CHIANTI—An Atomic Database for Emission Lines. XIII. Soft X-Ray Improvements and Other Changes Authors: Landi, E.; Young, P. R.; Dere, K. P.; Del Zanna, G.; Mason, H. E. Bibcode: 2013ApJ...763...86L Altcode: The CHIANTI spectral code consists of two parts: an atomic database and a suite of computer programs in Python and IDL. Together, they allow the calculation of the optically thin spectrum of astrophysical objects and provide spectroscopic plasma diagnostics for the analysis of astrophysical spectra. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, ionization, and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7.1 has been released, which includes improved data for several ions, recombination rates, and element abundances. In particular, it provides a large expansion of the CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the predicted emission in the 50-170 Å wavelength range. All data and programs are freely available at http://www.chiantidatabase.org and in SolarSoft, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net. Title: A Long-Lived Equatorial Coronal Hole and the Associated Solar Wind Authors: Ko, Y.; Young, P. R.; Muglach, K.; Wang, Y.; Lepri, S. T.; Laming, J. M.; Popecki, M. Bibcode: 2012AGUFMSH53A2261K Altcode: We study an equatorial coronal hole that came back rotation after rotation in a course of eight months from July 2007 to March 2008. This coronal hole was also one of the source regions of the solar wind measured by ACE during this period. The associated solar wind speed profiles for the 10 solar rotations are similar that start with a fast wind above 600 km/s and gradually lower down to below 400 km/s. The ion composition data indicate a decreasing trend in the ionization states of heavy ions, especially for the Fe ions. This recurring coronal hole presents a good opportunity for studying the relations between the solar wind at a range of speeds and the solar source that produces it. We present a detailed study of the solar wind from this coronal hole, concentrating on the ion charge and elemental composition properties, and the variation in the magnetic and spectroscopic properties in this source coronal hole. We discuss implications in the solar wind formation based on the relations between these properties of the source coronal hole and the associated solar wind. Title: LEMUR: Large European module for solar Ultraviolet Research. European contribution to JAXA's Solar-C mission Authors: Teriaca, Luca; Andretta, Vincenzo; Auchère, Frédéric; Brown, Charles M.; Buchlin, Eric; Cauzzi, Gianna; Culhane, J. Len; Curdt, Werner; Davila, Joseph M.; Del Zanna, Giulio; Doschek, George A.; Fineschi, Silvano; Fludra, Andrzej; Gallagher, Peter T.; Green, Lucie; Harra, Louise K.; Imada, Shinsuke; Innes, Davina; Kliem, Bernhard; Korendyke, Clarence; Mariska, John T.; Martínez-Pillet, Valentin; Parenti, Susanna; Patsourakos, Spiros; Peter, Hardi; Poletto, Luca; Rutten, Robert J.; Schühle, Udo; Siemer, Martin; Shimizu, Toshifumi; Socas-Navarro, Hector; Solanki, Sami K.; Spadaro, Daniele; Trujillo-Bueno, Javier; Tsuneta, Saku; Dominguez, Santiago Vargas; Vial, Jean-Claude; Walsh, Robert; Warren, Harry P.; Wiegelmann, Thomas; Winter, Berend; Young, Peter Bibcode: 2012ExA....34..273T Altcode: 2011ExA...tmp..135T; 2011arXiv1109.4301T The solar outer atmosphere is an extremely dynamic environment characterized by the continuous interplay between the plasma and the magnetic field that generates and permeates it. Such interactions play a fundamental role in hugely diverse astrophysical systems, but occur at scales that cannot be studied outside the solar system. Understanding this complex system requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1'' and 0.3''), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 170 Å and 1270 Å. The LEMUR slit covers 280'' on the Sun with 0.14'' per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km s - 1 or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission. Title: On VI Recombination Lines In Ultraviolet And Visible Spectra Of Rr Telescopii Authors: Young, Peter R. Bibcode: 2012AAS...22031901Y Altcode: Nineteen recombination lines of O VI are identified in ultraviolet and visible spectra of the symbiotic nova RR Telescopii at wavelengths between 1122 and 6203 A. Only three of the lines have previously been reported from astronomical spectra, and eight lines have never been reported from either astronomical or laboratory spectra. The lines represent transitions between levels with principal quantum numbers up to 13 and the strongest lines by flux occur at 1124.82, 2070.90 and 3434.66 A, corresponding to transitions 4-5, 5-6 and 6-7. As the lines are produced by recombination onto O VII they potentially allow O VII emitting regions in astrophysical plasmas to be probed at ultraviolet and visible wavelengths that otherwise can only be studied at X-ray wavelengths. Title: Radiogenic heating in exoplanet systems Authors: Carande, Bryce; Young, P.; McNamara, A. Bibcode: 2012AAS...22052503C Altcode: We study the effect of variations in the amount of radiogenic heating on the long-term thermal histories of exoplanets. The amount of radiogenic heating experienced by a planet is dependent on the abundance of long-lived radioisotopes (235U, 238U, 232Th, 40K) present in that stellar system. We explain a method to constrain the uranium abundance of stellar systems using more readily obtained measurements of europium absorption lines in the host star, and present results from a preliminary set of stars (including confirmed exoplanet hosts). We then use a parameterized convection model to simulate the thermal evolution of planetary mantles, given this variation in the abundance of radioisotopes between systems. Our parameterized convection model is based on the boundary layer theory, and includes a crustal heat flow parameter as well as the assumption of a critical Rayleigh number needed for convection. The simulated thermal evolution of a planet is found to depend more on the choice of heat-flow parameters, and less on the amount of radiogenic heating. Title: Hinode/EIS Flare Spectra During RHESSI Hard X-ray Bursts Authors: Young, Peter R.; Warren, H.; Doschek, G. Bibcode: 2012AAS...22020442Y Altcode: The standard flare model requires a beam of non-thermal electrons - generated at the coronal flare site - to hit the chromosphere and trigger heating and chromospheric evaporation. Ultraviolet spectrometers allow the heated, evaporating plasma to be observed and its properties measured. Observations of a M3 flare observed in 2011 September with Hinode/EIS, RHESSI and SDO/AIA will be presented, revealing the physical conditions in the flare ribbons at the time of the hard X-ray bursts. At the hottest temperatures (20 MK) upflowing plasma with speeds up to 500 km/s are found co-spatial with stationary plasma, while at cooler temperatures (0.5-2 MK) small downflows and large non-thermal broadening are found. These observations will be compared with predictions from multi-strand hydrodynamic simulations that take the RHESSI-derived electron beam spectrum as input. Title: O VI Recombination Lines in Ultraviolet and Visible Spectra of RR Telescopii Authors: Young, P. R. Bibcode: 2012ApJ...749....1Y Altcode: Nineteen recombination lines of O VI are identified in ultraviolet and visible spectra of the symbiotic nova RR Telescopii at wavelengths between 1122 and 6203 Å. Only three of the lines have previously been reported from astronomical spectra, and eight lines have never been reported from either astronomical or laboratory spectra. The lines represent transitions between levels with principal quantum numbers up to 13, and the strongest lines by flux occur at 1124.82, 2070.90, and 3434.66 Å, corresponding to transitions 4-5, 5-6, and 6-7. As the lines are produced by recombination onto O VII, they potentially allow O VII emitting regions in astrophysical plasmas to be probed at ultraviolet and visible wavelengths that otherwise can only be studied at X-ray wavelengths. Title: UV spectroscopy with IRIS - experience learned from Hinode/EIS Authors: Young, Peter Bibcode: 2012decs.confE.122Y Altcode: IRIS will be the fourth in a sequence of solar ultraviolet spectrometers, following on from CDS and SUMER on SOHO and Hinode/EIS. The experience gained from these missions will be valuable for ensuring that high quality science results emerge from IRIS right from the beginning of the mission. This presentation will summarize the experience gained from over five years of Hinode/EIS operations and science, and identify where that experience may benefit the IRIS team. Title: CHIANTI—An Atomic Database for Emission Lines. XII. Version 7 of the Database Authors: Landi, E.; Del Zanna, G.; Young, P. R.; Dere, K. P.; Mason, H. E. Bibcode: 2012ApJ...744...99L Altcode: The CHIANTI spectral code consists of an atomic database and a suite of computer programs to calculate the optically thin spectrum of astrophysical objects and carry out spectroscopic plasma diagnostics. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, and ionization and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7 has been released, which includes several new ions, significant updates to existing ions, as well as Chianti-Py, the implementation of CHIANTI software in the Python programming language. All data and programs are freely available at http://www.chiantidatabase.org, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net. Title: Velocity Measurements for a Solar Active Region Fan Loop from Hinode/EIS Observations Authors: Young, P. R.; O'Dwyer, B.; Mason, H. E. Bibcode: 2012ApJ...744...14Y Altcode: 2011arXiv1107.2362Y The velocity pattern of a fan loop structure within a solar active region over the temperature range 0.15-1.5 MK is derived using data from the EUV Imaging Spectrometer (EIS) on board the Hinode satellite. The loop is aligned toward the observer's line of sight and shows downflows (redshifts) of around 15 km s-1 up to a temperature of 0.8 MK, but for temperatures of 1.0 MK and above the measured velocity shifts are consistent with no net flow. This velocity result applies over a projected spatial distance of 9 Mm and demonstrates that the cooler, redshifted plasma is physically disconnected from the hotter, stationary plasma. A scenario in which the fan loops consist of at least two groups of "strands"—one cooler and downflowing, the other hotter and stationary—is suggested. The cooler strands may represent a later evolutionary stage of the hotter strands. A density diagnostic of Mg VII was used to show that the electron density at around 0.8 MK falls from 3.2 × 109 cm-3 at the loop base, to 5.0 × 108 cm-3 at a projected height of 15 Mm. A filling factor of 0.2 is found at temperatures close to the formation temperature of Mg VII (0.8 MK), confirming that the cooler, downflowing plasma occupies only a fraction of the apparent loop volume. The fan loop is rooted within a so-called outflow region that displays low intensity and blueshifts of up to 25 km s-1 in Fe XII λ195.12 (formed at 1.5 MK), in contrast to the loop's redshifts of 15 km s-1 at 0.8 MK. A new technique for obtaining an absolute wavelength calibration for the EIS instrument is presented and an instrumental effect, possibly related to a distorted point-spread function, that affects velocity measurements is identified. Title: Underflight Calibration of SOHO/CDS and Hinode/EIS with EUNIS-07 Authors: Wang, Tongjiang; Thomas, Roger J.; Brosius, Jeffrey W.; Young, Peter R.; Rabin, Douglas M.; Davila, Joseph M.; Del Zanna, Giulio Bibcode: 2011ApJS..197...32W Altcode: 2011arXiv1109.6598W Flights of Goddard Space Flight Center's Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rocket in 2006 and 2007 provided updated radiometric calibrations for Solar and Heliospheric Observatory/Coronal Diagnostic Spectrometer (SOHO/CDS) and Hinode/Extreme Ultraviolet Imaging Spectrometer (Hinode/EIS). EUNIS carried two independent imaging spectrographs covering wavebands of 300-370 Å in first order and 170-205 Å in second order. After each flight, end-to-end radiometric calibrations of the rocket payload were carried out in the same facility used for pre-launch calibrations of CDS and EIS. During the 2007 flight, EUNIS, SOHO/CDS, and Hinode/EIS observed the same solar locations, allowing the EUNIS calibrations to be directly applied to both CDS and EIS. The measured CDS NIS 1 line intensities calibrated with the standard (version 4) responsivities with the standard long-term corrections are found to be too low by a factor of 1.5 due to the decrease in responsivity. The EIS calibration update is performed in two ways. One uses the direct calibration transfer of the calibrated EUNIS-07 short wavelength (SW) channel. The other uses the insensitive line pairs, in which one member was observed by the EUNIS-07 long wavelength (LW) channel and the other by EIS in either the LW or SW waveband. Measurements from both methods are in good agreement, and confirm (within the measurement uncertainties) the EIS responsivity measured directly before the instrument's launch. The measurements also suggest that the EIS responsivity decreased by a factor of about 1.2 after the first year of operation (although the size of the measurement uncertainties is comparable to this decrease). The shape of the EIS SW response curve obtained by EUNIS-07 is consistent with the one measured in laboratory prior to launch. The absolute value of the quiet-Sun He II 304 Å intensity measured by EUNIS-07 is consistent with the radiance measured by CDS NIS in quiet regions near the disk center and the solar minimum irradiance recently obtained by CDS NIS and the Solar Dynamics Observatory/Extreme Ultraviolet Variability Experiment. Title: On the Solar Wind Ion Composition Properties With Source Regions from Low-Latitude and Polar Coronal Holes of Opposite Polarity Authors: Ko, Y.; Muglach, K.; Wang, Y.; Young, P. R.; Lepri, S. T.; Laming, J. M.; Popecki, M. Bibcode: 2011AGUFMSH43F..04K Altcode: During Years 2004-2007 there were frequent appearances of low-latitude coronal holes (CHs) and low-latitude extension of polar CHs. These CHs were the source regions of the solar wind measured in-situ at L1. We find that the ion composition has distinct properties between solar wind originating from CHs of opposite polarity. Specifically, the charge states measured by ACE/SWICS were systematically lower-ionized for solar wind ions from CHs of positive polarity (the 'south CH') than those of negative polarity (the 'north CH'), regardless of the solar wind speed. Such differentiation is apparent only in the low-latitude extension of polar CHs and those non-polar CHs with predicted footpoints at latitude higher than 15 degrees. Interestingly, earlier work based on Ulysses fast wind data during the declining/minimum phase of Cycle 22 found that it was the north polar CH that was associated with lower solar wind charge states, opposite to what we found in the following solar cycle. We present these results and search for solar properties that may be factors that govern this north-south difference. Title: Plasma Motions and Heating by Magnetic Reconnection in a 2007 May 19 Flare Authors: Hara, Hirohisa; Watanabe, Tetsuya; Harra, Louise K.; Culhane, J. Leonard; Young, Peter R. Bibcode: 2011ApJ...741..107H Altcode: Based on scanning spectroscopic observations with the Hinode EUV imaging spectrometer, we have found a loop-top hot source, a fast jet nearby, and an inflow structure flowing to the hot source that appeared in the impulsive phase of a long-duration flare at the disk center on 2007 May 19. The hot source observed in Fe XXIII and Fe XXIV emission lines has the electron temperature of 12 MK and density of 1 × 1010 cm-3. It shows excess line broadening, which exceeds the thermal Doppler width by ~100 km s-1, with a weak redshift of ~30 km s-1. We have also observed a blueshifted faint jet whose Doppler velocity exceeds 200 km s-1 with an electron temperature of 9 MK. Coronal plasmas with electron temperature of 1.2 MK and density of 2.5 × 109 cm-3 that flow into the loop-top region with a Doppler velocity of 20 km s-1 have been identified in the Fe XII observation. They disappeared near the hot source, possibly by being heated to the hotter faint jet temperature. From the geometrical relationships of these phenomena, we conclude that they provide evidence for magnetic reconnection that occurs near the loop-top region. The estimated reconnection rate is 0.05-0.1, which supports the Petschek-type magnetic reconnection. Further supporting evidence for the presence of the slow-mode and fast-mode MHD shocks in the reconnection geometry is given based on the observed quantities. Title: Forbidden and Intercombination Lines of RR Telescopii: Wavelength Measurements and Energy Levels Authors: Young, P. R.; Feldman, U.; Lobel, A. Bibcode: 2011ApJS..196...23Y Altcode: 2011arXiv1102.3101Y Ultraviolet and visible spectra of the symbiotic nova RR Telescopii are used to derive reference wavelengths for many forbidden and intercombination transitions of ions +1 to +6 of elements C, N, O, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, and Ca. The wavelengths are then used to determine new energy values for the levels within the ions' ground configurations or first excited configuration. The spectra were recorded by the Space Telescope Imaging Spectrograph of the Hubble Space Telescope and the Ultraviolet Echelle Spectrograph of the European Southern Observatory in 2000 and 1999, respectively, and cover 1140-6915 Å. Particular care was taken to assess the accuracy of the wavelength scale between the two instruments. An investigation of the profiles of the emission lines reveals that the nebula consists of at least two plasma components at different velocities. The components have different densities, and a simple model of the lines' emissions demonstrates that most of the lines principally arise from the high density component. Only these lines were used for the wavelength study. Title: On the ion composition properties in the solar wind from the north and south polar coronal holes Authors: Ko, Yuan-Kuen; Muglach, Karin; Wang, Yi-Ming; Young, Peter R.; Lepri, Susan T.; Laming, J. Martin; Popecki, Mark A. Bibcode: 2011shin.confE.158K Altcode: During Years 2005-2007 in the declining phase of Cycle 23 there were frequent appearances of equatorial coronal holes (CHs) and low-latitude extension of polar CHs that were the source regions of the solar wind measured in-situ at L1 a few days after these CHs past the central meridian. We find that the solar wind heavy ions emanating from the south and north polar CHs have distinct composition properties. Specifically, the charge states measured by ACE/SWICS were systematically lower for solar wind ions from the south polar CHs than those from the north polar CHs, regardless of the solar wind speed. Interestingly, earlier work based on Ulysses data during the declining/minimum phase of Cycle 22 found that it was the north polar CH that was associated with lower solar wind charge states, opposite to what we found in the following solar cycle. We present these results and search for solar properties that may be factors that govern this north-south difference. Implications in solar wind formation are discussed. Title: Flares Observed By Hinode During 14-18 February 2011 Authors: Young, Peter R.; Doschek, G. A.; Warren, H. P. Bibcode: 2011SPD....42.2213Y Altcode: 2011BAAS..43S.2213Y Active region AR 11158 produced an X1 flare and several M flares during 2011 February 14-18, and yielded the best set of flare observations captured by the Hinode satellite in four years. Finding the mechanisms responsible for flares was one of the major science goals of the Hinode mission, and data from AR 11158 will be presented to demonstrate how this goal is being achieved with Hinode data. A particular focus will be on relating plasma flows and temperature and density changes measured with the EIS instrument to the magnetic field evolution observed by SOT, and the coronal evolution observed with SDO/AIA. Title: EUV Spectral Line Formation and the Temperature Structure of Active Region Fan Loops: Observations with Hinode/EIS and SDO/AIA Authors: Brooks, David H.; Warren, Harry P.; Young, Peter R. Bibcode: 2011ApJ...730...85B Altcode: 2011arXiv1101.5240B With the aim of studying active region fan loops using observations from the Hinode EUV Imaging Spectrometer (EIS) and Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA), we investigate a number of inconsistencies in modeling the absolute intensities of Fe VIII and Si VII lines, and address why spectroheliograms formed from these lines look very similar despite the fact that ionization equilibrium calculations suggest that they have significantly different formation temperatures: log(Te /K) = 5.6 and 5.8, respectively. It is important to resolve these issues because confidence has been undermined in their use for differential emission measure (DEM) analysis, and Fe VIII is the main contributor to the AIA 131 Å channel at low temperatures. Furthermore, the strong Fe VIII 185.213 Å and Si VII 275.368 Å lines are the best EIS lines to use for velocity studies in the transition region, and for assigning the correct temperature to velocity measurements in the fans. We find that the Fe VIII 185.213 Å line is particularly sensitive to the slope of the DEM, leading to disproportionate changes in its effective formation temperature. If the DEM has a steep gradient in the log(Te /K) = 5.6-5.8 temperature range, or is strongly peaked, Fe VIII 185.213 Å and Si VII 275.368 Å will be formed at the same temperature. We show that this effect explains the similarity of these images in the fans. Furthermore, we show that the most recent ionization balance compilations resolve the discrepancies in absolute intensities. With these difficulties overcome, we combine EIS and AIA data to determine the temperature structure of a number of fan loops and find that they have peak temperatures of 0.8-1.2 MK. The EIS data indicate that the temperature distribution has a finite (but narrow) width < log (σ_{T_e}/K) = 5.5 which, in one detailed case, is found to broaden substantially toward the loop base. AIA and EIS yield similar results on the temperature, emission measure magnitude, and thermal distribution in the fans, though sometimes the AIA data suggest a relatively larger thermal width. The result is that both the Fe VIII 185.213 Å and Si VII 275.368 Å lines are formed at log(Te /K)~ 5.9 in the fans, and the AIA 131 Å response also shifts to this temperature. Title: Solar plasma spectroscopy: achievements and future challenges Authors: Del Zanna, Giulio; Tripathi, Durgesh; Young, Peter Bibcode: 2011A&G....52b..17D Altcode: MEETING REPORT Giulio Del Zanna, Durgesh Tripathi and Peter Young report on a meeting to celebrate the career of Helen Mason - and the development of an important field in solar physics. Title: Nurturing The STEM Pipeline: Graduate Student Leadership In NIRCam's Ongoing E/PO Mission For JWST Authors: Schlingman, Wayne M.; Stock, N.; Teske, J.; Tyler, K.; Biller, B.; Donley, J.; Hedden, A.; Knierman, K.; Young, P. Bibcode: 2011AAS...21743101S Altcode: 2011BAAS...4343101S The Astronomy Camp for Girl Scout Leaders is an education and public outreach (E/PO) program offered by the science team of the Near-InfraRed Camera (NIRCam) for NASA's 6.5-meter James Webb Space Telescope (JWST). Since 2003, astronomy graduate students have helped design and lead biannual "Train the Trainer” workshops for adults from the Girl Scouts of the USA (GSUSA), engaging these trainers in the process of scientific inquiry and equipping them to host astronomy-related activities at the troop level. These workshops have helped revise the national GSUSA badge curriculum and directly benefitted thousands of young girls of all ages, not only in general science and math education but also in specific astronomical and technological concepts relating to JWST. To date, nine graduate students have become members of NIRCam's E/PO team. They have developed curriculum and activities used to teach concepts in stellar nucleosynthesis, lookback time, galaxy classification, etc. They have also contributed to the overall strategic approach and helped lead more general activities in basic astronomy (night sky, phases of the Moon, the scale of the Solar System and beyond, stars, galaxies, telescopes, etc.) as well as JWST-specific research areas in extrasolar planetary systems and cosmology, to pave the way for girls and women to understand the first images from JWST. The resulting experience has empowered these students to propose and to develop their own E/PO programs after graduation as postdocs and young faculty. They also continue as part of NIRCam's growing worldwide network of 160 trainers teaching young women essential STEM-related concepts using astronomy, the night sky environment, applied math, engineering, and critical thinking. NIRCam and its E/PO program are funded by NASA under contract NAS5-02105. Title: The Temperature Dependence of Solar Active Region Outflows Authors: Warren, Harry P.; Ugarte-Urra, Ignacio; Young, Peter R.; Stenborg, Guillermo Bibcode: 2011ApJ...727...58W Altcode: 2010arXiv1008.2696W Spectroscopic observations with the EUV Imaging Spectrometer (EIS) on Hinode have revealed large areas of high-speed outflows at the periphery of many solar active regions. These outflows are of interest because they may connect to the heliosphere and contribute to the solar wind. In this paper, we use slit rasters from EIS in combination with narrowband slot imaging to study the temperature dependence and morphology of an outflow region and show that it is more complicated than previously thought. Outflows are observed primarily in emission lines from Fe XI to Fe XV. Observations at lower temperatures (Si VII), in contrast, show bright fan-like structures that are dominated by inflows. These data also indicate that the morphology of the outflows and the fans is different, outflows are observed in regions where there is no emission in Si VII. This suggests that the fans, which are often associated with outflows in studies involving imaging data, are not directly related to the active region outflows. Title: Expanding our Knowledge of the Chemical Composition of Nearby Stars Authors: Pagano, Michael D.; Young, P.; Butler, P. Bibcode: 2011AAS...21715302P Altcode: 2011BAAS...4315302P I will be presenting abundances of X elements and physical properties for a selection of nearby radial velocity planet search candidates. The abundances are derived from high resolution spectra from MIKE on Magellan. These are the first results of an attempt to create a uniform high resolution chemical abundance database that can be used to understand the chemical evolution of nearby stars, in particular those with potentially habitable worlds. These high resolution spectra are the first from a group of 600 nearby stars, obtained by Paul Butler(Carnigie Institute of Washington). Title: Hinode extreme-ultraviolet imaging spectrometer observations of a limb active region Authors: O'Dwyer, B.; Del Zanna, G.; Mason, H. E.; Sterling, A. C.; Tripathi, D.; Young, P. R. Bibcode: 2011A&A...525A.137O Altcode:
Aims: We investigate the electron density and temperature structure of a limb active region.
Methods: We have carried out a study of an active region close to the solar limb using observations from the Extreme-ultraviolet Imaging Spectrometer (EIS) and the X-ray telescope (XRT) on board Hinode. The electron density and temperature distributions of the coronal emission have been determined using emission line intensity ratios. Differential emission measure (DEM) analysis and the emission measure (EM) loci technique were used to examine the thermal structure of the emitting plasma as a function of distance from the limb.
Results: The highest temperature and electron density values are found to be located in the core of the active region, with a peak electron number density value of 1.9 × 1010 cm-3 measured using the Fe XII 186.887 Å to 192.394 Å line intensity ratio. The plasma along the line of sight in the active region was found to be multi-thermal at different distances from the limb. The EIS and XRT DEM analyses appear to be in agreement in the temperature interval from log T = 6.5-6.7.
Conclusions: Our results provide new constraints for models of coronal heating in active regions. Title: Science Objectives for an X-Ray Microcalorimeter Observing the Sun Authors: Laming, J. Martin; Adams, J.; Alexander, D.; Aschwanden, M; Bailey, C.; Bandler, S.; Bookbinder, J.; Bradshaw, S.; Brickhouse, N.; Chervenak, J.; Christe, S.; Cirtain, J.; Cranmer, S.; Deiker, S.; DeLuca, E.; Del Zanna, G.; Dennis, B.; Doschek, G.; Eckart, M.; Fludra, A.; Finkbeiner, F.; Grigis, P.; Harrison, R.; Ji, L.; Kankelborg, C.; Kashyap, V.; Kelly, D.; Kelley, R.; Kilbourne, C.; Klimchuk, J.; Ko, Y. -K.; Landi, E.; Linton, M.; Longcope, D.; Lukin, V.; Mariska, J.; Martinez-Galarce, D.; Mason, H.; McKenzie, D.; Osten, R.; Peres, G.; Pevtsov, A.; Porter, K. Phillips F. S.; Rabin, D.; Rakowski, C.; Raymond, J.; Reale, F.; Reeves, K.; Sadleir, J.; Savin, D.; Schmelz, J.; Smith, R. K.; Smith, S.; Stern, R.; Sylwester, J.; Tripathi, D.; Ugarte-Urra, I.; Young, P.; Warren, H.; Wood, B. Bibcode: 2010arXiv1011.4052L Altcode: We present the science case for a broadband X-ray imager with high-resolution spectroscopy, including simulations of X-ray spectral diagnostics of both active regions and solar flares. This is part of a trilogy of white papers discussing science, instrument (Bandler et al. 2010), and missions (Bookbinder et al. 2010) to exploit major advances recently made in transition-edge sensor (TES) detector technology that enable resolution better than 2 eV in an array that can handle high count rates. Combined with a modest X-ray mirror, this instrument would combine arcsecondscale imaging with high-resolution spectra over a field of view sufficiently large for the study of active regions and flares, enabling a wide range of studies such as the detection of microheating in active regions, ion-resolved velocity flows, and the presence of non-thermal electrons in hot plasmas. It would also enable more direct comparisons between solar and stellar soft X-ray spectra, a waveband in which (unusually) we currently have much better stellar data than we do of the Sun. Title: Evidence for magnetic flux cancelation leading to an ejective solar eruption observed by Hinode, TRACE, STEREO, and SoHO/MDI Authors: Sterling, A. C.; Chifor, C.; Mason, H. E.; Moore, R. L.; Young, P. R. Bibcode: 2010A&A...521A..49S Altcode:
Aims: We study the onset of a solar eruption involving a filament ejection on 2007 May 20.
Methods: We observe the filament in Hα images from Hinode/SOT and in EUV with TRACE and STEREO/SECCHI/EUVI. Hinode/XRT images are used to study the eruption in soft X-rays. From spectroscopic data taken with Hinode/EIS we obtain bulk-flow velocities, line profiles, and plasma densities in the onset region. The magnetic field evolution was observed in SoHO/MDI magnetograms.
Results: We observed a converging motion between two opposite polarity sunspots that form the primary magnetic polarity inversion line (PIL), along which resides filament material before eruption. Positive-flux magnetic elements, perhaps moving magnetic features (MMFs) flowing from the spot region, appear north of the spots, and the eruption onset occurs where these features cancel repeatedly in a negative-polarity region north of the sunspots. An ejection of material observed in Hα and EUV marks the start of the filament eruption (its “fast-rise”). The start of the ejection is accompanied by a sudden brightening across the PIL at the jet's base, observed in both broad-band images and in EIS. Small-scale transient brightenings covering a wide temperature range (Log Te = 4.8-6.3) are also observed in the onset region prior to eruption. The preflare transient brightenings are characterized by sudden, localized density enhancements (to above Log ne [ cm-3] = 9.75, in Fe XIII) that appear along the PIL during a time when pre-flare brightenings were occurring. The measured densities in the eruption onset region outside the times of those enhancements decrease with temperature. Persistent downflows (red-shifts) and line-broadening (Fe XII) are present along the PIL.
Conclusions: The array of observations is consistent with the pre-eruption sheared-core magnetic field being gradually destabilized by evolutionary tether-cutting flux cancelation that was driven by converging photospheric flows, and the main filament ejection being triggered by flux cancelation between the positive flux elements and the surrounding negative field. A definitive statement however on the eruption's ultimate cause would require comparison with simulations, or additional detailed observations of other eruptions occurring in similar magnetic circumstances.

The video that accompanies Fig. 3 is only available in electronic form at http://www.aanda.org Title: Active region moss. Basic physical parameters and their temporal variation Authors: Tripathi, D.; Mason, H. E.; Del Zanna, G.; Young, P. R. Bibcode: 2010A&A...518A..42T Altcode: 2010arXiv1005.2220T Context. Active region moss are transition region phenomena, first noted in the images recorded by the Transition Region and Coronal Explorer (TRACE) in λ171. Moss regions are thought to be the footpoints of hot loops (3-5 MK) seen in the core of active regions. These hot loops appear “fuzzy” (unresolved). Therefore, it is difficult to study the physical plasma parameters in individual hot core loops and hence their heating mechanisms. Moss regions provide an excellent opportunity to study the physics of hot loops. In addition, they allow us to study the transition region dynamics in the footpoint regions.
Aims: To derive the physical plasma parameters such as temperature, electron density, and filling factors in moss regions and to study their variation over a short (an hour) and a long time period (5 consecutive days).
Methods: Primarily, we have analyzed spectroscopic observations recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode. In addition we have used supplementary observations taken from TRACE and the X-Ray Telescope (XRT) aboard Hinode.
Results: The moss emission is strongest in the Fe XII and Fe XIII lines. Based on analyses using line ratios and emission measure we found that moss regions have a characteristic temperature of log T[K] = 6.2. The temperature structure in moss region remains almost identical from one region to another and it does not change with time. The electron densities measured at different locations in the moss regions using Fe XII ratios are about 1-3 × 1010 cm-3 and about 2-4 × 109 cm-3 using Fe XIII and Fe XIV. The densities in the moss regions are similar in different places and show very little variation over short and long time scales. The derived electron density substantially increased (by a factor of about 3-4 or even more in some cases) when a background subtraction was performed. The filling factor of the moss plasma can vary between 0.1-1 and the path length along which the emission originates is from a few 100 to a few 1000 kms long. By combining the observations recorded by TRACE, EIS and XRT, we find that the moss regions correspond to the footpoints of both hot and warm loops. Title: Multiple Component Outflows in an Active Region Observed with the EUV Imaging Spectrometer on Hinode Authors: Bryans, P.; Young, P. R.; Doschek, G. A. Bibcode: 2010ApJ...715.1012B Altcode: 2010arXiv1004.5085B We have used the Extreme Ultraviolet Imaging Spectrometer on the Hinode spacecraft to observe large areas of outflow near an active region. These outflows are seen to persist for at least 6 days. The emission line profiles suggest that the outflow region is composed of multiple outflowing components, Doppler-shifted with respect to each other. We have modeled this scenario by imposing a double-Gaussian fit to the line profiles. These fits represent the profile markedly better than a single-Gaussian fit for Fe XII and XIII emission lines. For the fastest outflowing components, we find velocities as high as 200 km s-1. However, there remains a correlation between the fitted line velocities and widths, suggesting that the outflows are not fully resolved by the double-Gaussian fit and that the outflow may be comprised of further components. Title: The Relative Intensity Calibration of Hinode/EIS and SOHO/SUMER Authors: Landi, E.; Young, P. R. Bibcode: 2010ApJ...714..636L Altcode: In this work, we have used simultaneous observations of the quiet Sun above the solar west limb obtained with the Hinode/Extreme ultraviolet Imaging Spectrograph and SOHO/SUMER instruments to determine their relative intensity calibration. We used two different methods: intensity ratios of lines emitted by the same upper level and observed in the spectral ranges of the two spectrometers, and the determination of the differential emission measure and total emission measure of the plasma. We review the uncertainties in our analysis and conclude that the relative calibration of the two instruments, as it can be determined from the standard data reduction software of each of them, is correct within uncertainties. Title: Absolute Radiometric Calibration Of EUNIS, And Calibration Updates For Hinode/EIS And SOHO/CDS Authors: Wang, Tongjiang; Thomas, R. J.; Brosius, J. W.; Young, P. R.; Rabin, D. M.; Davila, J. M. Bibcode: 2010AAS...21640704W Altcode: 2010BAAS...41..860W The Extreme-Ultraviolet Normal-Incidence Spectrograph sounding rocket payload was flown in 2006 (EUNIS-06) and 2007 (EUNIS-07), each time carrying two independent imaging spectrographs covering wave bands of 300-370 Angstrom in first order and 170-205 Angstrom in second order. For each flight, the absolute radiometric response of the EUNIS long-wavelength (LW) channel was directly measured in the same facility used for pre-flight calibrations of SOHO/CDS and Hinode/EIS. The wavelength range of the EUNIS LW channel overlaps that of CDS/NIS-1, and so can provide a direct calibration update for it. The EUNIS-06 observation shows that the efficiency of CDS/NIS-1 has decreased by a factor about 1.7 compared to that of the previously implemented calibration. Here we present an update to the absolute calibration for Hinode/EIS derived with a technique that combines a direct comparison of line intensities observed in cospatial EUNIS-07 and EIS spectra, along with density- and temperature-insensitive line intensity ratios. Title: Plasma Flows in Coronal Loops Authors: Young, Peter R.; Dwyer, B. O.; Mason, H. E. Bibcode: 2010AAS...21630004Y Altcode: A survey of plasma flows in coronal loops is underway using data from the Hinode/EIS instrument. The principal target is a study of flows in 1 MK (so-called 'warm' loops). Using emission lines formed between logT=5.6 and 6.2 it is possible to study the temperature dependence of the flows, and also the density of the emitting material. The results will be critical to making a definitive statement about whether apparent motions seen in TRACE 171 movies are due to actual mass motion or wave propagation. In addition we will also comment on the relation between the flows in warm loops and those in the newly-discovered active region outflow regions found by Hinode. Title: Elemental Abundance Variations in a Decaying EUV-Bright Region Authors: Ko, Yuan-Kuen; Landi, E.; Feldman, U.; Young, P. Bibcode: 2010AAS...21640515K Altcode: 2010BAAS...41..891K The EIS instrument on Hinode observed an EUV-bright region at N15 as it evolved during a course of four days on December 7-11, 2009. Although containing no sunspots, this region was associated with a weak magnetic concentration and exhibited large variations in loop and footpoint brightening. It was in a decay phase with dispersing magnetic field and weakening high-temperature emission. We present the variations of elemental abundances in this region among different spatial structures and with time. Implications in factors that can be associated with the First Ionization Potential (FIP) effect will be discussed. Title: New Fe VIII Line Identifications using Observations of the Quiet Sun Authors: Landi, E.; Young, P. R. Bibcode: 2010ApJ...713..205L Altcode: In this work, we study Fe VIII lines emitted in the 1000-1200 Å wavelength range that originate from levels that also emit transitions observed in the 190-200 Å wavelength range. The intensity ratios between such lines depend on atomic physics parameters only and not on the physical parameters of the emitting plasma: they are excellent tools to verify the relative intensity calibration of instruments operating in those wavelength ranges. We first carry out extensive atomic physics calculations to improve the accuracy of the predicted intensity ratios of those lines. We then compare the results with simultaneous Hinode/Extreme Ultraviolet Imaging Spectrometer and SOHO/SUMER observations of an off-disk quiet-Sun region, identify four new lines in the 1000-1200 Å range, and discuss their use for instrument calibration purposes. Title: The Composition of Dwarfs in the Solar Neighborhood Authors: Pagano, Michael D.; Young, P.; Timmes, F.; Bond, J. Bibcode: 2010AAS...21560503P Altcode: 2010BAAS...36.1129P We analyze published elemental abundances derived from high-resolution spectroscopy from radial velocity planet searches. We find that the sun has anomalous abundances compared to 130 nearby dwarfs. We use a uniform sample of low mass main sequence stars to reflect differences in initial composition rather than self-enrichment. We examine individual [element/Fe] ratios as a function of [Fe/H] for 13 elements. Scenarios for enrichment of outliers are discussed. Title: Delivery of Supernova Material to the ISM through Ejecta Knots Authors: Ellinger, C.; Young, P.; Rockefeller, G.; Fryer, C. Bibcode: 2010nuco.confE..29E Altcode: 2010PoS...100E..29E No abstract at ADS Title: New Flow Diagnostics with EIS Authors: Young, Peter Bibcode: 2010cosp...38.2923Y Altcode: 2010cosp.meet.2923Y The EUV Imaging Spectrometer (EIS) on board Hinode obtains high resolution spectra in the wavelength ranges 170-212 and 246-292 angstroms, giving access to a large number of emission lines from the solar transition region and corona. Line of sight velocities from individual spatial pixels (1 arcsec2 )canbemeasuredthroughDopplershif tstoaprecisionof upto1km/sandanaccuracyof upto5k Title: The effect of 12C + 12C rate uncertainties on s-process yields Authors: Bennett, M. E.; Hirschi, R.; Pignatari, M.; Diehl, S.; Fryer, C.; Herwig, F.; Hungerford, A.; Magkotsios, G.; Rockefeller, G.; Timmes, F.; Wiescher, M.; Young, P. Bibcode: 2010JPhCS.202a2023B Altcode: 2010arXiv1002.2788B The slow neutron capture process in massive stars (the weak s-process) produces most of the s-only isotopes in the mass region 60 < A < 90. The nuclear reaction rates used in simulations of this process have a profound effect on the final s-process yields. We generated 1D stellar models of a 25Modot star varying the 12C + 12C rate by a factor of 10 and calculated full nucleosynthesis using the post-processing code PPN. Increasing or decreasing the rate by a factor of 10 affects the convective history and nucleosynthesis, and consequently the final yields. Title: Characteristics of the Nonthermal Velocity Signature Observed in the Impulsive Phase of the 2007 May 19 Flare Authors: Hara, H.; Watanabe, T.; Bone, L. A.; Culhane, J. L.; van Driel-Gesztelyi, L.; Young, P. R. Bibcode: 2009ASPC..415..459H Altcode: The Hinode EUV Imaging Spectrometer (EIS) observed a long duration flare with a weak impulsive phase that appears to conform to the standard two-ribbon flare reconnection model. EIS scanned the flare site during the impulsive phase and observed Fe XXIII and Fe XXIV line emission that closely followed the flare hard X-ray emission while the line profiles showed significant non-thermal broadening. We suggest that a shock originating at the reconnection site which sweeps up and heats the coronal plasma can account for our observations. Title: New Fe IX Line Identifications Using Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation and Hinode/EIS Joint Observations of the Quiet Sun Authors: Landi, E.; Young, P. R. Bibcode: 2009ApJ...707.1191L Altcode: In this work, we study joint observations of Hinode/EUV Imaging Spectrometer (EIS) and Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation of Fe IX lines emitted by the same level of the high energy configuration 3s 23p 54p. The intensity ratios of these lines are dependent on atomic physics parameters only and not on the physical parameters of the emitting plasma, so that they are excellent tools to verify the relative intensity calibration of high-resolution spectrometers that work in the 170-200 Å and 700-850 Å wavelength ranges. We carry out extensive atomic physics calculations to improve the accuracy of the predicted intensity ratio, and compare the results with simultaneous EIS-SUMER observations of an off-disk quiet Sun region. We were able to identify two ultraviolet lines in the SUMER spectrum that are emitted by the same level that emits one bright line in the EIS wavelength range. Comparison between predicted and measured intensity ratios, wavelengths and energy separation of Fe IX levels confirms the identifications we make. Blending and calibration uncertainties are discussed. The results of this work are important for cross-calibrating EIS and SUMER, as well as future instrumentation. Title: Chianti—An Atomic Database for Emission Lines. XI. Extreme-Ultraviolet Emission Lines of Fe VII, Fe VIII, and Fe IX Observed by Hinode/EIS Authors: Young, P. R.; Landi, E. Bibcode: 2009ApJ...707..173Y Altcode: 2009arXiv0907.3488Y A detailed study of emission lines from Fe VII, Fe VIII, and Fe IX observed by the EUV Imaging Spectrometer on board the Hinode satellite is presented. Spectra in the ranges 170-212 Å and 246-292 Å show strongly enhanced lines from the upper solar transition region (temperatures 5.4 <= log T <= 5.9) allowing a number of new line identifications to be made. Comparisons of Fe VII lines with predictions from a new atomic model reveal new plasma diagnostics, however there are a number of disagreements between theory and observation for emission line ratios insensitive to density and temperature, suggesting improved atomic data are required. Line ratios for Fe VIII also show discrepancies with theory, with the strong λ185.21 and λ186.60 lines underestimated by 60%-80% compared to lines between 192 and 198 Å. A newly identified multiplet between 253.9 and 255.8 Å offers excellent temperature diagnostic opportunities relative to the lines between 185 and 198 Å, however the atomic model underestimates the strength of these lines by factors of 3-6. Two new line identifications are made for Fe IX at wavelengths 176.959 Å and 177.594 Å, while seven other lines between 186 and 200 Å are suggested to be due to Fe IX but for which transition identifications cannot be made. The new atomic data for Fe VII and Fe IX are demonstrated to significantly modify models for the response function of the Transition Region And Coronal Explorer 195 Å imaging channel, affecting temperature determinations from this channel. The data will also affect the response functions for other solar EUV imaging instruments such as SOHO/EIT, STEREO/EUVI, and the upcoming AIA instrument on the Solar Dynamics Observatory. Title: CHIANTI—An Atomic Database for Emission Lines. X. Spectral Atlas of a Cold Feature Observed with Hinode/EUV Imaging Spectrometer Authors: Landi, E.; Young, P. R. Bibcode: 2009ApJ...706....1L Altcode: 2009arXiv0907.3490L In this work, we report on a cold, bright portion of an active region observed by the Hinode/EUV Imaging Spectrometer. The emitting plasma was very bright at transition region temperatures, and the intensities of lines of ions formed between 105 and 106 K were enhanced over normal values. The data set constitutes an excellent laboratory where the emission of transition region ions can be tested. We first determine the thermal structure of the observed plasma, and then we use it (1) to develop a spectral atlas, and (2) to assess the quality of CHIANTI atomic data by comparing predicted emissivities with observed intensities. We identify several lines never observed before in solar spectra, and find an overall very good agreement between CHIANTI-predicted emissivities and observations. Title: Hot Plasma in Nonflaring Active Regions Observed by the Extreme-Ultraviolet Imaging Spectrometer on Hinode Authors: Ko, Yuan-Kuen; Doschek, George A.; Warren, Harry P.; Young, Peter R. Bibcode: 2009ApJ...697.1956K Altcode: 2009arXiv0903.3029K The Extreme-Ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft obtains high-resolution spectra of the solar atmosphere in two wavelength ranges: 170-210 and 250-290 Å. These wavelength regions contain a wealth of emission lines covering temperature regions from the chromosphere/transition region (e.g., He II, Si VII) up to flare temperatures (Fe XXIII, Fe XXIV). Of particular interest for understanding coronal heating is a line of Ca XVII at 192.858 Å, formed near a temperature of 6 × 106 K. However, this line is blended with two Fe XI and six O V lines. In this paper we discuss a specific procedure to extract the Ca XVII line from the blend. We have performed this procedure on the raster data of five active regions (ARs) and a limb flare, and demonstrated that the Ca XVII line can be satisfactorily extracted from the blend if the Ca XVII flux contributes to at least ~10% of the blend. We show examples of the high-temperature corona depicted by the Ca XVII emission and find that the Ca XVII emission has three morphological features in these ARs: (1) "fat" medium-sized loops confined in a smaller space than the 1 million degree corona, (2) weaker, diffuse emission surrounding these loops that spread over the core of the AR, and (3) the locations of the strong Ca XVII loops are often weak in line emission formed from the 1 million degree plasma. We find that the emission measure ratio of the 6 million degree plasma relative to the cooler 1 million degree plasma in the core of the ARs, using the Ca XVII to Fe XI line intensity ratio as a proxy, can be as high as 10. Outside of the AR core where the 1 million degree loops are abundant, the ratio has an upper limit of about 0.5. Title: Temperature Tomography of a Coronal Sigmoid Supporting the Gradual Formation of a Flux Rope Authors: Tripathi, Durgesh; Kliem, Bernhard; Mason, Helen E.; Young, Peter R.; Green, Lucie M. Bibcode: 2009ApJ...698L..27T Altcode: 2009arXiv0904.4782T Multiwavelength observations of a sigmoidal (S-shaped) solar coronal source by the EUV Imaging Spectrometer and the X-Ray Telescope aboard the Hinode spacecraft and by the EUV Imager aboard STEREO are reported. The data reveal the coexistence of a pair of J-shaped hot arcs at temperatures T>2 MK with an S-shaped structure at somewhat lower temperatures (T ≈ 1-1.3 MK). The middle section of the S-shaped structure runs along the polarity inversion line of the photospheric field, bridging the gap between the arcs. Flux cancellation occurs at the same location in the photosphere. The sigmoid forms in the gradual decay phase of the active region, which does not experience an eruption. These findings correspond to the expected signatures of a flux rope forming, or being augmented, gradually by a topology transformation inside a magnetic arcade. In such a transformation, the plasma on newly formed helical field lines in the outer flux shell of the rope (S-shaped in projection) is expected to enter a cooling phase once the reconnection of their parent field line pairs (double-J shaped in projection) is complete. Thus, the data support the conjecture that flux ropes can exist in the corona prior to eruptive activity. Title: Physical Properties In An Equatorial Coronal Hole And Its Connection To The Solar Wind Properties Authors: Ko, Yuan-Kuen; Young, P. R.; Lepri, S.; Popecki, M.; Muglach, K.; Wang, Y.; Laming, J. M. Bibcode: 2009SPD....40.1405K Altcode: We analyze the physical properties in an equatorial coronal hole that was observed by Hinode/EIS in two consecutive solar rotations in February and March of 2009. This coronal hole is the obvious source region for the solar wind measured in-situ by ACE and STEREO that exhibits the typical fast-to-slow characteristics in proton speed. We determine the electron density and temperature structures at several locations in the coronal hole that may correspond to the footpoints of the solar wind measured in-situ. We discuss the variations of such properties between locations as well as between the two rotations. We compare and discuss such variations in the coronal hole with the properties in the solar wind, in particular, the ion charge composition. Title: CHIANTI - an atomic database for emission lines. IX. Ionization rates, recombination rates, ionization equilibria for the elements hydrogen through zinc and updated atomic data Authors: Dere, K. P.; Landi, E.; Young, P. R.; Del Zanna, G.; Landini, M.; Mason, H. E. Bibcode: 2009A&A...498..915D Altcode: Aims: The goal of the CHIANTI atomic database is to provide a set of atomic data for the interpretation of astrophysical spectra emitted by collisionally dominated, high temperature, optically thin sources.
Methods: A complete set of ground level ionization and recombination rate coefficients has been assembled for all atoms and ions of the elements of H through Zn and inserted into the latest version of the CHIANTI database, CHIANTI 6. Ionization rate coefficients are taken from the recent work of Dere (2007, A&A, 466, 771) and recombination rates from a variety of sources in the literature. These new rate coefficients have allowed the calculation of a new set of ionization equilibria and radiative loss rate coefficients. For some ions, such as Fe VIII and Fe IX, there are significant differences from previous calculations. In addition, existing atomic parameters have been revised and new atomic parameters inserted into the database.
Results: For each ion in the CHIANTI database, elemental abundances, ionization potentials, atomic energy levels, radiative rates, electron and proton collisional rate coefficients, ionization and recombination rate coefficients, and collisional ionization equilibrium populations are provided. In addition, parameters for the calculation of the continuum due to bremsstrahlung, radiative recombination and two-photon decay are provided. A suite of programs written in the Interactive Data Language (IDL) are available to calculate line and continuum emissivities and other properties. All data and programs are freely available at http://wwwsolar.nrl.navy.mil/chianti Title: Multiple Component Outflows in Active Regions observed by EIS Authors: Bryans, Paul; Doschek, G. A.; Young, P. R. Bibcode: 2009SPD....40.1221B Altcode: We have used the Extreme Ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft to observe large areas of outflow near an active region. These outflows are seen to persist for a number of days. The emission line profiles suggest that the outflow region is composed of multiple outflowing components, Doppler-shifted with respect to each other. We have modelled this scenario by imposing a double-Gaussian fit to the line profiles; these fits represent the profile markedly better than a single Gaussian fit. For the fastest outflowing components, we find velocities as high as 200 km/s. However, there remains a correlation between the fitted line velocities and widths, suggesting that the outflows are not fully resolved by the double-Gaussian fit and that the outflow may be comprised of further components. Title: CHIANTI Version 6.0 - Inclusion of Ionization and Recombination Rates Authors: Dere, Kenneth P.; Landi, E.; Young, P.; Del Zanna, G.; Mason, H.; Landini, M. Bibcode: 2009SPD....40.1504D Altcode: A new version of the CHIANTI atomic database for astrophysical spectroscopy is being prepared for imminent release. This will constitute Version 6.0. The main focus of this release is the inclusion of ionization cross-sections and rate coefficients from Dere (2007) and recombination rate coefficients from the literature, in particular, the calculations of Badnell and colleagues. A new set of ionization equilibria have been calculated from these rate coefficients. These show some significant differences from previous calculations. Atomic data for many ions have been revised and new calculations are included that enable the calculation of spectra of ions new to the CHIANTI database. The radiative loss function has been calculated based on the CHIANTI Version 6 database for both coronal and photospheric abundances.

A paper describing CHIANTI Version 6.0 in detail has been accepted for publication in Astronomy and Astrophysics. Title: Improved Atomic Models for EUV Imaging Instruments Authors: Young, Peter R.; Landi, E. Bibcode: 2009SPD....40.1506Y Altcode: A combination of new atomic data and new line identifications made from Hinode/EIS spectra have expanded and improved atomic models for Fe VII and Fe IX emission lines in the extreme ultraviolet wavelength range. These have a significant effect on the response functions of EUV imaging instruments, particularly the 195 angstrom filters used by SOHO/EIT, TRACE, STEREO/EUVI and SDO/AIA, and will be discussed. Title: Active Region Loops: Hinode/Extreme-Ultraviolet Imaging Spectrometer Observations Authors: Tripathi, Durgesh; Mason, Helen E.; Dwivedi, Bhola N.; del Zanna, Giulio; Young, Peter R. Bibcode: 2009ApJ...694.1256T Altcode: 2009arXiv0901.0095T We have carried out a study of active region loops using observations from the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode using 1'' raster data for an active region observed on 2007 May 19. We find that active region structures which are clearly discernible in cooler lines (≈1 MK) become "fuzzy" at higher temperatures (≈2 MK). The active region was comprised of redshifted emissions (downflows) in the core and blueshifted emissions (upflows) at the boundary. The flow velocities estimated in the two regions located near the footpoints of coronal loop showed redshifted emission at transition region temperature and blueshifted emission at coronal temperature. The upflow speed in these regions increased with temperature. For more detailed study we selected one particular well-defined loop. Downward flows are detected along the coronal loop, being stronger in lower-temperature lines (rising up to 60 km s-1 near the footpoint). The downflow was localized toward the footpoint in transition region lines (Si VII) and toward the loop top in high-temperature line (Fe XV). By carefully accounting for the background emission we found that the loop structure was close to isothermal for each position along the loop, with the temperature rising from around 0.8 MK to 1.5 MK from the close to the base to higher up toward the apex (≈75 Mm). We derived electron density using well-established line ratio diagnostic techniques. Electron densities along the active region loop were found to vary from 1010 cm-3 close to the footpoint to 108.5 cm-3 higher up. A lower electron density, varying from 109 cm-3 close to the footpoint to 108.5 cm-3 higher up, was found for the lower temperature density diagnostic. Using these densities we derived filling factors in along the coronal loop which can be as low as 0.02 near the base of the loop. The filling factor increased with projected height of the loop. These results provide important constraints on coronal loop modeling. Title: Fe XIII Density Diagnostics in the EIS Observing Wavelengths Authors: Watanabe, T.; Hara, H.; Yamamoto, N.; Kato, D.; Sakaue, H. A.; Murakami, I.; Kato, T.; Nakamura, N.; Young, P. R. Bibcode: 2009ApJ...692.1294W Altcode: The diagnostic capability of Fe XIII line features seen in the 170-210 Å waveband of the EUV Imaging Spectrometer (EIS) on Hinode is investigated, with emphasis on density diagnostics applied to solar active regions. Four diagnostic line pairs are found to yield consistent densities ranging from 108.5 to 109.5 cm-3 across an active region using a new theoretical model of the ion. In separate EIS observations of a small flare, the widely used line pair, Fe XIII λ203.8/λ202.0, is found to reach the high density limit predicted by a new theoretical model of the iron ion. Title: High-precision density measurements in the solar corona. I. Analysis methods and results for Fe XII and Fe XIII Authors: Young, P. R.; Watanabe, T.; Hara, H.; Mariska, J. T. Bibcode: 2009A&A...495..587Y Altcode: 2008arXiv0805.0958Y Aims: The EUV Imaging Spectrometer (EIS) instrument on board the Hinode satellite has access to some of the best coronal density diagnostics, and the high sensitivity of the instrument now allows electron number density, N_e, measurements to an unprecedented precision of up to ±5% in active regions. This paper gives a thorough overview of data analysis issues for the best diagnostics of Fe XII and Fe XIII and assesses the accuracy of the measurements.
Methods: Two density diagnostics each from Fe XII (λ186.88/λ195.12 and λ196.64/λ195.12) and Fe XIII (λ196.54/λ202.04 and λ203.82/λ202.04) are analysed in two active region datasets from 2007 May 3 and 6 that yield densities in the range 8.5≤ log (N_e/cm-3)≤ 11.0. The densities are derived using v5.2 of the CHIANTI atomic database. Blending, line fitting, and instrumental issues are discussed, and line fit parameters presented.
Results: The Fe XII and Fe XIII diagnostics show broadly the same trend in density across the active region, consistent with their similar temperatures of formation. However, the high precision of the EIS measurements demonstrates significant discrepancies of up to 0.5 dex in derived log Ne values, with Fe XII always giving higher densities than Fe XIII. The discrepancies may partly be due to real physical differences between the emitting regions of the two plasmas, but the dominant factor lies in the atomic models of the two ions. Two specific problems are identified for Fe XII λ196.64 and Fe XIII λ203.82: the former is found to be underestimated in strength by the CHIANTI atomic model, while the high-density limit of the λ203.82/λ202.04 ratio appears to be inaccurate in the CHIANTI atomic model. The small grating tilt of the EIS instrument is found to be very significant when deriving densities from emission lines separated by more than a few angstroms. Revised wavelengths of 196.518± 0.003 Å and 196.647± 0.003 Å are suggested for the Fe XIII λ196.54 and Fe XII λ196.64 lines, respectively. Title: New EUV Fe IX Emission Line Identifications from Hinode/EIS Authors: Young, P. R. Bibcode: 2009ApJ...691L..77Y Altcode: 2008arXiv0810.5028Y Four Fe IX transitions in the wavelength range 188-198 Å are identified for the first time in spectra from the EUV Imaging Spectrometer on board the Hinode satellite. In particular the emission line at 197.86 Å is unblended and close to the peak of the EIS sensitivity curve, making it a valuable diagnostic of plasma at around 800,000 K — a critical temperature for studying the interface between the corona and transition region. Theoretical ratios among the four lines predicted from the CHIANTI database reveal weak sensitivity to density and temperature with observed values consistent with theory. The ratio of λ197.86 relative to the λ171.07 resonance line of Fe IX is found to be an excellent temperature diagnostic, independent of density, and the derived temperature in the analyzed data set is log T = 5.95, close to the predicted temperature of maximum ionization of Fe IX. Title: On the ultraviolet signatures of small scale heating in coronal loops Authors: Parenti, S.; Young, P. R. Bibcode: 2008A&A...492..857P Altcode: 2010arXiv1009.4112P Aims: Studying the statistical properties of solar ultraviolet emission lines could provide information about the nature of small scale coronal heating. We expand on previous work to investigate these properties. We study whether the predicted statistical distribution of ion emission line intensities produced by a specified heating function is affected by the isoelectronic sequence to which the ion belongs, as well as the characteristic temperature at which it was formed (as found previously). Particular emphasis is placed on the strong resonance lines belonging to the lithium isoelectronic sequence. Predictions for emission lines observed by existing space-based UV spectrometers are given. The effects on the statistics of a line when observed with a wide-band imaging instrument rather than a spectrometer are also investigated.
Methods: We use a hydrodynamic model to simulate the UV emission of a loop system heated by nanoflares on small, spatially unresolved scales. We select lines emitted at similar temperatures but belonging to different isoelectronic groups: Fe IX and Ne VIII, Fe XII and Mg X, Fe XVIII, Fe XIX and Fe XXIV.
Results: Our simulations confirm previous results that almost all lines have an intensity distribution that follows a power-law, in a similar way to the heating function. However, only the high temperature lines best preserve the heating function's power law index (Fe XIX being the best ion in the case presented here). The Li isoelectronic lines have different statistical properties with respect to the lines from other sequences, due to the extended high temperature tail of their contribution functions. However, this is not the case for Fe XXIV which may be used as a diagnostic of the coronal heating function. We also show that the power-law index of the heating function is effectively preserved when a line is observed by a wide-band imaging instrument rather than a spectromenter. Title: X-ray energy flow and radiography measurements of evolving density perturbations Authors: Moore, A. S.; Graham, P.; Taylor, M. J.; Foster, J. M.; Sorce, C.; Reighard, A.; MacLaren, S.; Young, P.; Glendinning, G.; Blue, B. E.; Back, C. A.; Hund, J. Bibcode: 2008APS..DPPPP6113M Altcode: X-radiation transport through plasma density gradients, such as N-waves, form a closely coupled system that is challenging to simulate. Such situations are a key component of the physics of laser-heated hohlraums occurring in the laser-heated cavity and also in the laser-entry and any diagnostic holes. In addition the similarity to some astrophysical conditions may mean that such experiments can be used as a laboratory-scale analogue for their investigation. To better understand these phenomena, we present results from a series of experiments performed at the Omega laser facility. Using a laser-heated hohlraum drive, a tantalum aerogel with an initial seed perturbation is heated, and x-rays initially free-stream through the perturbation before they fill with plasma and radiation transport becomes diffuse. We present energy flux measurements diagnosed using two different methods, and complementary radiography results that achieve sufficient contrast, despite the high background of the hohlraum, to enable the complex shock interactions and stagnation to be directly observed. These results are compared with simulations performed using a 2-D Eulerian hydrocode, which are able to reproduce the overall energetics, and much of the details of the deceleration shock and axial stagnation region at the centre of the slit. Title: Magnetic flux cancellation associated with a recurring solar jet observed with Hinode, RHESSI, and STEREO/EUVI Authors: Chifor, C.; Isobe, H.; Mason, H. E.; Hannah, I. G.; Young, P. R.; Del Zanna, G.; Krucker, S.; Ichimoto, K.; Katsukawa, Y.; Yokoyama, T. Bibcode: 2008A&A...491..279C Altcode: Aims: We study the physical properties of a recurring solar active region jet observed in X-rays and extreme-ultraviolet (EUV).
Methods: Multi-wavelength data from all three instruments on board Hinode were analysed. X-ray imaging and spectroscopy of the microflaring emission associated with the jets was performed with the Reuven Ramaty High Energy Spectroscopic Imager (RHESSI). Associated EUV jets were observed with the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)/Extreme Ultraviolet Imager (EUVI) on board STEREO.
Results: We found a correlation between recurring magnetic flux cancellation close to a pore, the X-ray jet emission, and associated Ca II H ribbon brightenings. We estimated the lower limit for the decrease in magnetic energy associated with the X-ray jet emission at 3 × 1029 erg. The recurring plasma ejection was observed simultaneously at EUV and X-ray temperatures, associated with type III radio bursts and microflaring activity at the jet footpoint.
Conclusions: The recurring jet (EUV and X-ray) emissions can be attributed to chromospheric evaporation flows due to recurring coronal magnetic reconnection. In this process, the estimated minimum loss in the magnetic energy is sufficient to account for the total energy required to launch the jet.

Movie of Fig. 3 is only available in electronic form via http://www.aanda.org Title: Active Region Microflares From Hinode and RHESSI Authors: Chifor, C.; Hannah, I. G.; Mason, H. E.; Isobe, H.; Yokoyama, T.; Young, P. R.; Tripathi, D. Bibcode: 2008ASPC..397..164C Altcode: We are studying microflares (A, B-C class flares) in active regions using coordinated observations from Hinode and RHESSI. Hinode/EIS has unprecedented diagnostic power for small, transient activity in the solar corona, providing temperature, density, and velocity information. For this purpose, we designed and ran an EIS observing sequence to provide high-cadence data at both transition region and coronal temperatures. A preliminary analysis of these observations is reported, with one data set given as an example. Title: Detection of Waves in the Solar Corona: Kink or Alfvén? Authors: van Doorsselaere, T.; Nakariakov, V. M.; Verwichte, E.; Young, P. R. Bibcode: 2008ESPM...12.2.81V Altcode: Last year, Tomczyk et al. (2007) have conclusively proven that low amplitude (1km/s) waves are ubiquitously present in the corona. A few months later, this was followed up with the discovery that chromospheric spicules carry tremendous wave power (De Pontieu et al., 2007). These new developments form a basis for coronal seismological magnetic field mapping of the corona and chromosphere. However, this must be based upon a confident identification of the observed wave mode.

Using basic MHD wave theory, we demonstrate that the only way to interpret the observed wave motions is in terms of fast magnetoacoustic kink waves. We prove that the interpretation in terms of Alfven waves, as was put forward in the original articles, does not explain the observed phenomenology, while the fast magnetoacoustic kink waves reproduce the required observational constraints.

To underline the potential of magnetic field mapping, we discuss a recent observation of coronal loop kink oscillations observed with Hinode/EIS. Because of its spectroscopic and imaging capabilities, we are able to measure the loop density, simultaneously with the loop length. This allows us to determine the magnetic field with unprecedented accuracy. Title: Density Structure in Active Regions from Hinode/EIS Authors: Tripathi, D.; Mason, H. E.; Young, P. R.; Chifor, C.; Del Zanna, G. Bibcode: 2008ASPC..397...45T Altcode: The Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode provides an excellent opportunity to study the physical plasma parameters in spatially resolved coronal features. In this paper we present the density structure in an active region at many different temperatures. The active region was rastered on May 01, 2007 with the 2^{''} slit. We find that the electron density is highest in the core of the active region where it exceeds log_{10} N_e = 10.5. Title: Hinode EIS and XRT Observations of Hot Jets in Coronal Holes - Does the Plasma Escape? Authors: Baker, D.; van Driel-Gesztelyi, L.; Kamio, S.; Culhane, J. L.; Harra, L. K.; Sun, J.; Young, P. R.; Matthews, S. A. Bibcode: 2008ASPC..397...23B Altcode: X-ray jets have been detected in the extreme ultraviolet (EUV) and soft X-ray observations of Hinode's EIS and XRT instruments. Both instruments were used to observe the jets in polar and on-disk coronal holes (CHs). Here, we present a multi-wavelength study of an X-ray jet and its associated bright point found in an equatorial CH on 19 June 2007. Light curves (LCs) in 22 different emission lines were compared to that of Hinode/XRT. As we found in a previous study of two polar X-ray jets, this jet shows a post-jet increase in its EUV LCs. The post-jet enhancement appears cooler than the jet. We suggest this feature arises because the hot plasma of the jet, having failed to reach escape speeds, cools and falls back along the near vertical paths expected to be created by reconnection with open field lines of CHs. In addition to the increase in post-jet EUV intensity, we found tentative evidence of impact heating possibly caused by the fall-back of plasma. Title: Coronal magnetic field measurement using loop oscillations observed by Hinode/EIS Authors: Van Doorsselaere, T.; Nakariakov, V. M.; Young, P. R.; Verwichte, E. Bibcode: 2008A&A...487L..17V Altcode: We report the first spectroscopic detection of a kink MHD oscillation of a solar coronal structure by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on the Japanese Hinode satellite. The detected oscillation has an amplitude of 1 km s-1 in the Doppler shift of the FeXII 195 Å spectral line (1.3~MK), and a period of 296~s. The unique combination of EIS's spectroscopic and imaging abilities enables us to measure simultaneously the mass density and length of the oscillating loop. This enables us to measure directly the magnitude of the local magnetic field, the fundamental coronal plasma parameter, as 39 ± 8~G, with unprecedented accuracy. This proof of concept makes EIS an exclusive instrument for the full scale implementation of the MHD coronal seismological technique. Title: Coronal Plasma Motions near Footpoints of Active Region Loops Revealed from Spectroscopic Observations with Hinode EIS Authors: Hara, Hirohisa; Watanabe, Tetsuya; Harra, Louise K.; Culhane, J. Leonard; Young, Peter R.; Mariska, John T.; Doschek, George A. Bibcode: 2008ApJ...678L..67H Altcode: The solar active region 10938 has been observed from the disk center to the west limb with the Hinode EUV Imaging Spectrometer. In the disk-center observation, subsonic upflow motions of tens of km s-1 and enhanced nonthermal velocities have been found near the footpoints of the active region loops assuming a single Gaussian approximation for the emission-line profiles. When the same part of the active region is observed near the limb, both upflows and enhanced nonthermal velocities essentially decrease. There is a strong correlation between Doppler velocity and nonthermal velocity. Significant deviations from a single Gaussian profile are found in the blue wing of the line profiles for the upflows. These suggest that there are unresolved high-speed upflows. We discuss the implications for coronal heating mechanisms. Title: Outflows at the Edges of Active Regions: Contribution to Solar Wind Formation? Authors: Harra, L. K.; Sakao, T.; Mandrini, C. H.; Hara, H.; Imada, S.; Young, P. R.; van Driel-Gesztelyi, L.; Baker, D. Bibcode: 2008ApJ...676L.147H Altcode: The formation of the slow solar wind has been debated for many years. In this Letter we show evidence of persistent outflow at the edges of an active region as measured by the EUV Imaging Spectrometer on board Hinode. The Doppler velocity ranged between 20 and 50 km s-1 and was consistent with a steady flow seen in the X-Ray Telescope. The latter showed steady, pulsing outflowing material and some transverse motions of the loops. We analyze the magnetic field around the active region and produce a coronal magnetic field model. We determine from the latter that the outflow speeds adjusted for line-of-sight effects can reach over 100 km s-1. We can interpret this outflow as expansion of loops that lie over the active region, which may either reconnect with neighboring large-scale loops or are likely to open to the interplanetary space. This material constitutes at least part of the slow solar wind. Title: Density structure of an active region and associated moss using Hinode/EIS Authors: Tripathi, D.; Mason, H. E.; Young, P. R.; Del Zanna, G. Bibcode: 2008A&A...481L..53T Altcode: 2008arXiv0802.3311T Context: Studying the problem of active region heating requires precise measurements of physical plasma parameters such as electron density, temperature, etc. It is also important to understand the relationship of coronal structures with the magnetic field. The Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode provides a rare opportunity to derive electron density simultaneously at different temperatures.
Aims: We study the density structure and characterise plasma in active regions and associated moss regions. In addition, we study its relationship to the photospheric magnetic field.
Methods: We used data recorded by the EIS, together with magnetic field measurements from the Michelson Doppler Imager (MDI) aboard SoHO and images recorded with the Transition Region And Coronal Explorer (TRACE) and X-Ray Telescope (XRT/Hinode).
Results: We find that the hot core of the active region is densest with values as high as 1010.5 cm-3. The electron density estimated in specific regions in the active region moss decreases with increasing temperature. The moss areas were located primarily on one side of the active region, and they map the positive polarity regions almost exactly. The density within the moss region was highest at log T=5.8{-}6.1, with a value around 1010.0{-10.5} cm-3. The moss densities were highest in the strong positive magnetic field region. However, there was no such correlation for the negative polarity areas, where there was a large sunspot. Title: X-Ray Enabled MOCASSIN: A Three-dimensional Code for Photoionized Media Authors: Ercolano, Barbara; Young, Peter R.; Drake, Jeremy J.; Raymond, John C. Bibcode: 2008ApJS..175..534E Altcode: 2007arXiv0710.2103E We present a new version of the fully three-dimensional photoionization and dust radiative transfer code, MOCASSIN, that uses a Monte Carlo approach for the transfer of radiation. The X-ray enabled MOCASSIN allows a fully geometry-independent description of low-density gaseous environments strongly photoionized by a radiation field extending from radio to gamma rays. The code has been thoroughly benchmarked against other established codes routinely used in the literature, using simple plane-parallel models designed to test performance under standard conditions. We show the results of our benchmarking exercise and discuss the applicability and limitations of the new code, which should be of guidance for future astrophysical studies with MOCASSIN. Title: Erratum: "Outflows at the Edges of Active Regions: Contribution to Solar Wind Formation?" (ApJ, 676, L147 [2008]) Authors: Harra, L. K.; Sakao, T.; Mandrini, C. H.; Hara, H.; Imada, S.; Young, P. R.; van Driel-Gesztelyi, L.; Baker, D. Bibcode: 2008ApJ...677L.159H Altcode: No abstract at ADS Title: An active region jet observed with Hinode Authors: Chifor, C.; Young, P. R.; Isobe, H.; Mason, H. E.; Tripathi, D.; Hara, H.; Yokoyama, T. Bibcode: 2008A&A...481L..57C Altcode: Aims:We study the physical properties of an active region (AR) jet in order to probe the mechanisms responsible for it.
Methods: We report 2007 January 15/16 observations of a recurring jet situated on the west side of NOAA AR 10938. Multi-wavelength data from all three instruments onboard Hinode were analysed. This paper focuses on one instance of a jet observed with the Hinode/EUV Imaging Spectrometer (EIS). Using EIS raster data we measured the temperatures, Doppler shifts, density, and filling factor.
Results: A strong blue-shifted component and an indication of a weak red-shifted component at the base of the jet was observed around Log Te = 6.2. The up-flow velocities exceeded 150 km s-1. The jet component was seen over a range of temperatures between 5.4 and 6.4 in Log T_e. Using Fe XII λ186 and λ195 line ratios, we measured densities above Log Ne = 11 for the high-velocity up-flow component. We found that the density of the high-velocity up-flow increases with velocity. We estimate the filling factor in the jet up-flow to be <0.03. With the Hinode/Solar Optical Telescope (SOT), we observed recurrent (quasi periodic) magnetic flux cancelations just before the recurrent jet emission was seen in images taken with the X-ray Telescope (XRT).
Conclusions: The high-velocity up-flows, together with the density dependence on velocity, support an evaporation scenario for the acceleration of this jet. The high density and small filling factor, coupled with the high Doppler velocities are strongly suggestive of multiple small-scale magnetic reconnection events being responsible for the production of both EUV and X-ray jets. Title: Spatial Distribution of Nucleosynthesis Products in Cassiopeia A: Comparison Between Observations and 3D Explosion Models Authors: Young, P.; Ellinger, C.; Arnett, D.; Fryer, C.; Rockefeller, G. Bibcode: 2008nuco.confE..20Y Altcode: 2008PoS....53E..20Y; 2008arXiv0811.4655Y We examine observed heavy element abundances in the Cassiopeia A supernova remnant as a constraint on the nature of the Cas A supernova. We compare bulk abundances from 1D and 3D explosion models and spatial distribution of elements in 3D models with those derived from X-ray observations. We also examine the cospatial production of 26Al with other species. We find that the most reliable indicator of the presence of 26Al in unmixed ejecta is a very low S/Si ratio (~0.05). Production of N in O/S/Si-rich regions is also indicative. The biologically important element P is produced at its highest abundance in the same regions. Proxies should be detectable in supernova ejecta with high spatial resolution multiwavelength observations. Title: Complete nucleosynthesis calculations for low-mass stars from NuGrid Authors: Pignatari, M.; Herwig, F.; Bennet, M. E.; Diehl, S.; Fryer, C. L.; Hirschi, R.; Hungerford, A.; Magkotsios, G.; Rockefeller, G.; Timmes, F. X.; Young, P. Bibcode: 2008nuco.confE..75P Altcode: 2008PoS....53E..75P; 2008arXiv0811.4658P Many nucleosynthesis and mixing processes of low-mass stars as they evolve from the Main Sequence to the thermal-pulse Asymptotic Giant Branch phase (TP-AGB) are well understood (although of course important physics components, e.g. rotation, magnetic fields, gravity wave mixing, remain poorly known). Nevertheless, in the last years presolar grain measurements with high resolution have presented new puzzling problems and strong constraints on nucleosynthesis processes in stars. The goal of the NuGrid collaboration is to present uniform yields for a large range of masses and metallicities, including low$-$mass stars and massive stars and their explosions. Here we present the first calculations of stellar evolution and high-resolution, post-processing simulations of an AGB star with an initial mass of 2 M_sun and solar-like metallicity (Z=0.01), based on the post-processing code PPN. In particular, we analyze the formation and evolution of the radiative 13C-pocket between the 17th TP and the 18th TP. The s-process nucleosynthesis profile of a sample of heavy isotopes is also discussed, before the next convective TP occurrence. Title: Nucleosynthesis simulations for a wide range of nuclear production sites from NuGrid Authors: Herwig, F.; Diehl, S.; Fryer, C. L.; Hirschi, R.; Hungerford, A.; Magkotsios, G.; Pignatari, M.; Rockefeller, G.; Timmes, F. X.; Young, P.; Bennet, M. E. Bibcode: 2008nuco.confE..23H Altcode: 2008PoS....53E..23H; 2008arXiv0811.4653H Simulations of nucleosynthesis in astrophysical environments are at the intersection of nuclear physics reaction rate research and astrophysical applications, for example in the area of galactic chemical evolution or near-field cosmology. Unfortunately, at present the available yields for such applications are based on heterogeneous assumptions between the various contributing nuclear production sites, both in terms of modeling the thermodynamic environment itself as well as the choice of specifc nuclear reaction rates and compilations. On the other side, new nuclear reaction rate determinations are often taking a long time to be included in astrophysical applications. The NuGrid project addresses these issues by providing a set of codes and a framework in which these codes interact. In this contribution we describe the motivation, goals and first results of the NuGrid project. At the core is a new and evolving post-processing nuclesoynthesis code (PPN) that can follow quiescent and explosive nucleosynthesis following multi-zone 1D-stellar evolution as well as multi-zone hydrodynamic input, including explosions. First results are available in the areas of AGB and massive stars. Title: NuGrid: s process in massive stars Authors: Hirschi, R.; Frischknecht, U.; Pignatari, M.; Thielemann, F. K.; Bennet, M. E.; Diehl, S.; Fryer, C. L.; Herwig, F.; Hungerford, A.; Magkotsios, G.; Rockefeller, G.; Timmes, F. X.; Young, P. Bibcode: 2008nuco.confE..83H Altcode: 2008arXiv0811.4654H; 2008PoS....53E..83H The s-process production in massive stars at very low metallicities is expected to be negligible due to the low abundance of the neutron source 22Ne, to primary neutron poisons and decreasing iron seed abundances. However, recent models of massive stars including the effects of rotation show that a strong production of 22Ne is possible in the helium core, as a consequence of the primary nitrogen production (observed in halo metal poor stars). Using the PPN post-processing code, we studied the impact of this primary 22Ne on the s process. We find a large production of s elements between strontium and barium, starting with the amount of primary 22Ne predicted by stellar models. There are several key reaction rate uncertainties influencing the s-process efficiency. Among them, 17O(alpha,gamma) may play a crucial role strongly influencing the s process efficiency, or it may play a negligible role, according to the rate used in the calculations. We also report on the development of a new parallel (MPI) post-processing code (MPPNP) designed to follow the complete nucleosynthesis in stars on highly resolved grids. We present here the first post-processing run from the ZAMS up to the end of helium burning for a 15 solar mass model. Title: Ti44 and Ni56 in core-collapse supernovae Authors: Magkotsios, G.; Timmes, F. X.; Wiescher, M.; Fryer, C. L.; Hungerford, A.; Young, P.; Bennet, M. E.; Diehl, S.; Herwig, F.; Hirschi, R.; Pignatari, M.; Rockefeller, G. Bibcode: 2008nuco.confE.112M Altcode: 2008arXiv0811.4651M; 2008PoS....53E.112M We investigate the physical conditions where 44Ti and 56Ni are created in core-collapse supernovae. In this preliminary work we use a series of post-processing network calculations with parametrized expansion profiles that are representative of the wide range of temperatures, densities and electron-to-baryon ratios found in 3D supernova simulations. Critical flows that affect the final yields of 44Ti and 56Ni are assessed. Title: NuGrid: Nuclear Burning in 3-D Double Degenerate Merger Simulations Authors: Diehl, S.; Fryer, C.; Hungerford, A.; Rockefeller, G.; Bennet, M. E.; Herwig, F.; Hirschi, R.; Pignatari, M.; Magkotsios, G.; Timmes, F. X.; Young, P.; Clayton, G. C.; Motl, P.; Tohline, J. E. Bibcode: 2008nuco.confE.155D Altcode: 2008PoS....53E.155D No abstract at ADS Title: Nucleosynthetic Constraints on the Progenitor of Cassiopeia A Authors: Ellinger, C.; Young, P.; Fryer, C. L. Bibcode: 2008nuco.confE.206E Altcode: 2008PoS....53E.206E No abstract at ADS Title: Nucleosynthetic Yields from Gamma-Ray Bursts Authors: Rockefeller, G.; Fryer, C. L.; Young, P.; Bennet, M. E.; Diehl, S.; Herwig, F.; Hirschi, R.; Hungerford, A.; Pignatari, M.; Magkotsios, G.; Timmes, F. X. Bibcode: 2008nuco.confE.119R Altcode: 2008PoS....53E.119R No abstract at ADS Title: Trends in 56Ni and 44Ti Synthesis in Core-Collapse Supernovae from NuGrid Authors: Hungerford, A.; Fryer, C. L.; Timmes, F. X.; Young, P.; Bennet, M. E.; Diehl, S.; Herwig, F.; Hirschi, R.; Pignatari, M.; Magkotsios, G.; Rockefeller, G. Bibcode: 2008nuco.confE.106H Altcode: 2008PoS....53E.106H No abstract at ADS Title: FeXIII density diagnostics for solar coronal and flare plasmas Authors: Watanabe, Tetsuya; Hara, Hirohisa; Yamamoto, Norimasa; Kato, Takako; Young, Peter R. Bibcode: 2008cosp...37.3434W Altcode: 2008cosp.meet.3434W Density sensitive FeXIII line ratios were obtained by EUV Imaging Spectrometer (EUV) on Hinode for quiet-sun, active region, and flare plasmas. Consistency of density estimates derived from various density-sensitive line pairs appearing in the EIS observing wavelengths will be discussed in comparison with theoretical models. The intensity ratios of FeXIIIλ203.8A/202.0A in flaring active region show its high-density limit, suggesting that densities at the foot points of flaring looops exceed 1012 cm-3 , though the value itself is not exactly consistent with the laboratory data. Title: Coronal Plasma Motions near Footpoints of Active Region Loops Revealed from Spectroscopic Observations with {it Hinode} EIS Authors: Hara, Hirohisa; Watanabe, Tetsuya; Harra, Louise K.; Culhane, J. Leonard; Young, Peter R.; Doschek, G. A.; Mariska, John Bibcode: 2008cosp...37.1175H Altcode: 2008cosp.meet.1175H We have observed the solar active region 10938 from the disk center to the west limb with the Hinode EUV Imaging Spectrometer. In the disk center observation subsonic upflow motions of tens of km s-1 and enhanced nonthermal velocities have been found near the footpoints of the active-region loops assuming a single Gaussian approximation for the emission-line profiles. When the same part of the active region is observed near the limb, both upflows and enhanced nonthermal velocities essentially decrease, clearly showing that the enhanced nonthermal velocities in the disk center observation are mainly due to line-of-sight motions, which are likely parallel to magnetic field lines of the coronal loops. There is a strong correlation between Doppler velocity and nonthermal velocity in the upflow regions. The enhancement in the blue wing of the line profiles is found for the upflows as a significant deviation from a single Gaussian profile. These suggest that there are unresolved high-speed upflows near the footpoints of active region loops. We discuss the implications for coronal heating mechanisms. Title: Nucleosynthesis from Supernovae as a Function of Explosion Energy from NuGrid Authors: Fryer, C.; Young, P.; Bennet, M. E.; Diehl, S.; Herwig, F.; Hirschi, R.; Hungerford, A.; Pignatari, M.; Magkotsios, G.; Rockefeller, G.; Timmes, F. X. Bibcode: 2008nuco.confE.101F Altcode: 2008PoS....53E.101F No abstract at ADS Title: Solar Transition Region Features Observed with Hinode/EIS Authors: Young, Peter R.; Del Zanna, Giulio; Mason, Helen E.; Doschek, George A.; Culhane, Len; Hara, Hirohisa Bibcode: 2007PASJ...59S.727Y Altcode: 2007arXiv0706.1856Y Two types of solar active region feature prominent at transition region temperatures are identified in Hinode/EIS data of AR 10938 taken on 2007 January 20. The footpoints of 1 MK TRACE loops are shown to emit strongly in emission lines formed at log T = 5.4-5.8, allowing the temperature increase along the footpoints to be clearly seen. A density diagnostic of Mg VII yields the density in the footpoints, with one loop showing a decrease from 3 × 109 cm-3 at the base to 1.5 × 109 cm-3 at a projected height of 20 Mm. The second feature is a compact active region transition region brightening which is particularly intense in O V emission (log T = 5.4) but also has a signature at temperatures up to log T = 6.3. The Mg VII diagnostic gives a density of 4 × 1010 cm-3, and emission lines of Mg VI and Mg VII show line profiles broadened by 50kms-1 and wings extending beyond ± 200kms-1. Continuum emission in the short wavelength band is also found to be enhanced, and is suggested to be free-bound emission from recombination onto He+. Title: Hinode EUV Study of Jets in the Sun's South Polar Corona Authors: Culhane, Len; Harra, Louise K.; Baker, Deborah; van Driel-Gesztelyi, Lidia; Sun, Jian; Doschek, George A.; Brooks, David H.; Lundquist, Loraine L.; Kamio, Suguru; Young, Peter R.; Hansteen, Viggo H. Bibcode: 2007PASJ...59S.751C Altcode: A number of coronal bright points and associated plasma jet features were seen in an observation of the South polar coronal hole during 2007 January. The 40" wide slot was used at the focus of the Hinode EUV Imaging Spectrometer to provide spectral images for two of these events. Light curves are plotted for a number of emission lines that include He II 256Å (0.079MK) and cover the temperature interval from 0.4MK to 5.0MK. Jet speed measurements indicate values less than the escape velocity. The light curves show a post-jet enhancement in a number of the cooler coronal lines indicating that after a few minutes cooling, the plasma fell back to its original acceleration site. This behavior has not been previously observed by e.g., the Yohkoh Soft X-ray Telescope due to the comparatively high temperature cut-off in its response. The observations are consistent with the existing models that involve magnetic reconnection between emerging flux and the ambient open field lines in the polar coronal hole. However we do not have sufficient coverage of lines from lower temperature ion species to register the Hα-emitting surge material that is associated with some of these models. Title: Temperature and Density Structures of Solar Corona, A Test of Iron Line Diagnostic Capability of EIS Instrument on Board Hinode Authors: Watanabe, Tetsuya; Hara, Hirohisa; Culhane, Len; Harra, Louise K.; Doschek, George A.; Mariska, John T.; Young, Peter R. Bibcode: 2007PASJ...59S.669W Altcode: Increased diagnostic capability of the EUV Imaging Spectrometer (EIS) aboard Hinode (former Solar-B) has been demonstrated with a set of iron emission lines emerging in the two EIS observing wavelength bands (170-210Å and 250-290Å) and their line-intensity ratios. ``Abundance-uncertainty'' free relative emission measure distributions as a function of temperature were deduced using only iron emission lines of various ionization stages. First-light spectra of a small active region show iron lines ranging from FeVIII (185.2Å and 186.6Å) through FeXVII (204.7Å, 254.9Å, and 269.4Å). Spectra of a C-class flare confirms the presence of one of these higher temperature lines (FeXVII at 254.9Å) more clearly, as well showing FeXXIV (192.0Å and 255.1Å) and FeXXIII (263.8Å), which are normally only seen at flare temperatures. Title: On-axis Hohlraum Radiography associated with N-Waves in Stellar Atmospheres. Authors: Moore, A. S.; Foster, J.; Graham, P.; Taylor, M.; MacLaren, S.; Young, P.; Glendinning, G.; Reighard, A.; Sorce, C.; Back, C.; Hund, J.; Blue, B. Bibcode: 2007APS..DPPYO5012M Altcode: The propagation of weak shocks in a stellar atmosphere, in conjunction with the high x-ray flux cannot be well-described using weak-shock theory. Experiments performed at the LLE OMEGA laser attempt to study shock dynamics similar radiation conditions. Point-projection radiography was performed along the axis of a 160eV hohlraum, illuminating the structures formed by the ablation of a 0.2mm annular slot in a solid Ta disc. Diagnosed whilst laser-driven, the platform also enables quantitative measurements of x-ray flow through high-Z foam slot. Backlit images of the radiatively-driven slot show complex `bubble-like' features at the intersection of ablation fronts. Despite the 3D aspects of the experiment, 2D simulations, using the radiation-hydrodynamics code are an excellent qualitative match to the data, demonstrating that structures result from a high pressure spike that forms from the colliding ablation fronts driving a blast wave-like expansion into the dense stagnation region. Title: The Temperature and Density Structure of an Active Region Observed with the Extreme-Ultraviolet Imaging Spectrometer on Hinode Authors: Doschek, George A.; Mariska, John T.; Warren, Harry P.; Culhane, Len; Watanabe, Tetsuya; Young, Peter R.; Mason, Helen E.; Dere, Kenneth P. Bibcode: 2007PASJ...59S.707D Altcode: The Extreme-Ultraviolet Imaging Spectrometer (EIS) on Hinode produces high resolution spectra that can be combined via rasters into monochromatic images of solar structures, such as active regions. Electron temperature and density maps of the structures can be obtained by imaging the structures in different spectral lines with ratios sensitive to either temperature or density. Doppler maps and ion temperature maps can be made from spectral line wavelengths and profiles, respectively. In this paper we discuss coronal temperature and density distributions within an active region, illustrating the power of EIS for solar plasma diagnostics. Title: EUV Emission Lines and Diagnostics Observed with Hinode/EIS Authors: Young, Peter R.; Del Zanna, Giulio; Mason, Helen E.; Dere, Ken P.; Landi, Enrico; Landini, Massimo; Doschek, George A.; Brown, Charles M.; Culhane, Len; Harra, Louise K.; Watanabe, Tetsuya; Hara, Hirohisa Bibcode: 2007PASJ...59S.857Y Altcode: 2007arXiv0706.1857Y Quiet Sun and active region spectra from the Hinode/EIS instrument are presented, and the strongest lines from different temperature regions discussed. A list of emission lines recommended to be included in EIS observation studies is presented based on analysis of blending and diagnostic potential using the CHIANTI atomic database. In addition we identify the most useful density diagnostics from the ions covered by EIS. Title: Measurements of X-ray energy flow through evolving density gradients to validate the modeling of stellar atmospheres Authors: Graham, P.; Foster, J.; Moore, A.; Taylor, M.; MacLaren, S.; Young, P.; Glendinning, G.; Reighard, A.; Sorce, C.; Back, C.; Hund, J.; Blue, B. Bibcode: 2007APS..DPPYO5011G Altcode: Density perturbations, such as N-waves, in stellar atmospheres are coupled to the X-ray radiation field and so their evolution is challenging to simulate [1]. To assess current modeling capabilities an analogous problem was generated on the LLE OMEGA laser using a hohlraum to drive X-rays through tantalum aerogel with an initial seed perturbation. X-rays diffuse preferentially through the lower density material and the flow changes over time as the heated mass evolves. The energy flow was diagnosed using two methods, direct flux and hohlraum calorimetry, which are compared to assess the best technique. In both cases multiple flux diagnostics on different lines of sight were used, including photodiode and photoconductive detectors, to crosscheck results. In addition, 2D framing images of X-ray emission were taken to correlate with the flux measurements. The suite of data will be presented and compared against modeling. [1] Mihalas & Mihalas, `Foundations of Radiation Hydrodynamics', Dover (1999). Title: Coronal Dimming Observed with Hinode: Outflows Related to a Coronal Mass Ejection Authors: Harra, Louise K.; Hara, Hirohisa; Imada, Shinsuke; Young, Peter R.; Williams, David R.; Sterling, Alphonse C.; Korendyke, Clarence; Attrill, Gemma D. R. Bibcode: 2007PASJ...59S.801H Altcode: Coronal dimming has been a signature used to determine the source of plasma that forms part of a coronal mass ejection (CME) for many years. Generally dimming is detected through imaging instruments such as SOHO EIT by taking difference images. Hinode tracked active region 10930 from which there were a series of flares. We combined dimming observations from EIT with Hinode data to show the impact of flares and coronal mass ejections on the region surrounding the flaring active region, and we discuss evidence that the eruption resulted in a prolonged steady outflow of material from the corona. The dimming region shows clear structure with extended loops whose footpoints are the source of the strongest outflow (≈ 40 kms-1). This confirms that the loops that are disrupted during the event do lose plasma and hence are likely to form part of the CME. This is the first time the velocity of the coronal plasma has been measured in an extended dimming region away from the flare core. In addition there was a weaker steady outflow from extended, faint loops outside the active region before the eruption, which is also long lasting. These were disturbed and the velocity increased following the flare. Such outflows could be the source of the slow solar wind. Title: Application of CHIANTI to Solar-B Authors: Dere, K.; Landi, E.; Del Zanna, G.; Young, P.; Mason, H.; Landini, M. Bibcode: 2007ASPC..369...35D Altcode: CHIANTI (http://wwwsolar.nrl.navy.mil/chianti.html) has been developed to support the interpretation of solar and astrophysical spectroscopic measurements. The most recent release, version 5.0 (Landi et al. 2005) presents an improvement over previous versions by including new large scale datasets for Fe ions from Fe XVII to Fe XXIV for X-ray emission and improved atomic data for EUV line emission. We will demonstrate how this can be applied to the analysis of XRT and EIS data, in particular. For example, new excitation rates for Fe XII have resolved a long standing problem in the use of Fe XII line ratios as accurate density diagnostics. Current work involves improvements to ionization and recombination rates which will also be useful in the interpretation of Solar-B data Title: Studying Transition Region Phenomena with Solar-B/EIS Authors: Young, P. Bibcode: 2007ASPC..369..307Y Altcode: 2007arXiv0708.1672Y Transition region lines in active regions can become strongly enhanced in coronal footpoints and active region blinkers. The weak transition region lines found in the Solar-B/EIS wavebands will thus become useful for diagnostic studies of these events. EIS count rates predicted from SOHO/CDS spectra are presented, and a Mg VII density diagnostic is highlighted. Title: Nonthermal Velocities in Solar Active Regions Observed with the Extreme-Ultraviolet Imaging Spectrometer on Hinode Authors: Doschek, G. A.; Mariska, J. T.; Warren, H. P.; Brown, C. M.; Culhane, J. L.; Hara, H.; Watanabe, T.; Young, P. R.; Mason, H. E. Bibcode: 2007ApJ...667L.109D Altcode: We discuss nonthermal velocities in an active region as revealed by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. The velocities are derived from spectral line profiles in the extreme-ultraviolet (EUV) from a strong line of Fe XII at 195.12 Å by fitting each line profile to a Gaussian function. We compare maps of the full width at half-maximum values, the Fe XII spectral line intensity, the Fe XII Doppler shift, the electron temperature, and electron density. We find that the largest widths in the active region do not occur in the most intense regions, but seem to concentrate in less intense regions, some of which are directly adjacent to coronal loops, and some of which concentrate in regions which also exhibit relative Doppler outflows. The increased widths can also occur over extended parts of the active region. Title: The EUV Imaging Spectrometer for Hinode Authors: Culhane, J. L.; Harra, L. K.; James, A. M.; Al-Janabi, K.; Bradley, L. J.; Chaudry, R. A.; Rees, K.; Tandy, J. A.; Thomas, P.; Whillock, M. C. R.; Winter, B.; Doschek, G. A.; Korendyke, C. M.; Brown, C. M.; Myers, S.; Mariska, J.; Seely, J.; Lang, J.; Kent, B. J.; Shaughnessy, B. M.; Young, P. R.; Simnett, G. M.; Castelli, C. M.; Mahmoud, S.; Mapson-Menard, H.; Probyn, B. J.; Thomas, R. J.; Davila, J.; Dere, K.; Windt, D.; Shea, J.; Hagood, R.; Moye, R.; Hara, H.; Watanabe, T.; Matsuzaki, K.; Kosugi, T.; Hansteen, V.; Wikstol, Ø. Bibcode: 2007SoPh..243...19C Altcode: The EUV Imaging Spectrometer (EIS) on Hinode will observe solar corona and upper transition region emission lines in the wavelength ranges 170 - 210 Å and 250 - 290 Å. The line centroid positions and profile widths will allow plasma velocities and turbulent or non-thermal line broadenings to be measured. We will derive local plasma temperatures and densities from the line intensities. The spectra will allow accurate determination of differential emission measure and element abundances within a variety of corona and transition region structures. These powerful spectroscopic diagnostics will allow identification and characterization of magnetic reconnection and wave propagation processes in the upper solar atmosphere. We will also directly study the detailed evolution and heating of coronal loops. The EIS instrument incorporates a unique two element, normal incidence design. The optics are coated with optimized multilayer coatings. We have selected highly efficient, backside-illuminated, thinned CCDs. These design features result in an instrument that has significantly greater effective area than previous orbiting EUV spectrographs with typical active region 2 - 5 s exposure times in the brightest lines. EIS can scan a field of 6×8.5 arc min with spatial and velocity scales of 1 arc sec and 25 km s−1 per pixel. The instrument design, its absolute calibration, and performance are described in detail in this paper. EIS will be used along with the Solar Optical Telescope (SOT) and the X-ray Telescope (XRT) for a wide range of studies of the solar atmosphere. Title: Coronal dimming observed with Hinode Authors: Harra, Louise; Hara, H.; Young, P.; Williams, D.; Sterling, A.; Attrill, G. Bibcode: 2007AAS...210.6305H Altcode: 2007BAAS...39..172H Coronal dimming has been a technique used to determine the source of plasma that forms part of a coronal mass ejection. Generally dimming is detected through imaging instruments such as SOHO EIT by taking difference images. In a few cases the SOHO-CDS has been used to determine outflowing material, and a decrease in density. Hinode tracked active region 10930 from which there were a series of flares. We combine dimming observations from EIT with Hinode data to show the impact of flares and coronal mass ejections on the region surrounding the flaring active region, and we discuss evidence that the eruption resulted in a prolonged steady outflow of material from the corona. Title: Hinode EIS Observations of Solar Active Regions Authors: Mariska, John T.; Doschek, G. A.; Warren, H. P.; Brooks, D. H.; Young, P. R.; Watanabe, T.; Culhane, J. L. Bibcode: 2007AAS...210.7202M Altcode: 2007BAAS...39R.178M The EUV Imaging Spectrometer (EIS) on the Hinode satellite provides high spatial and spectral resolution data along a 512 arcsec slit in two wavelength ranges, 170--210 Angstroms and 250--290 Angstroms. These wavelengths mostly contain emission lines from upper transition region and coronal plasmas. Emission from these wavelengths is routinely imaged using instruments such as the EIT on SOHO and TRACE, but there are few high-resolution spectra to aid in more deeply understanding the physical conditions and dynamics associated with the intensity variations seen in the images. In this presentation, we show some initial results from EIS active region studies aimed at mapping the density, temperature, nonthermal broadening, and Doppler shifts in active regions. This presentation focusses on spectroheliograms of active regions in diagnostically interesting spectral lines. These show the overall active region morphology and the behavior of Doppler shifts, nonthermal velocities, and densities as a function of position, but at the expense of high time resolution. Other presentations will focus on how the observed physical parameters vary with time. Title: Multi-wavelength Analysis of a Quiet Solar Region Authors: Tsiropoula, G.; Tziotziou, K.; Giannikakis, J.; Young, P.; Schühle, U.; Heinzel, P. Bibcode: 2007ASPC..368..171T Altcode: 2007arXiv0704.1592T We present observations of a solar quiet region obtained by the ground-based Dutch Open Telescope (DOT), and by instruments on the spacecraft SOHO and TRACE. The observations were obtained during a coordinated observing campaign on October 2005. The aim of this work is to present the rich diversity of fine-scale structures that are found at the network boundaries and their appearance in different instruments and different spectral lines that span the photosphere to the corona. Detailed studies of these structures are crucial to understanding their dynamics in different solar layers, as well as the role such structures play in the mass balance and heating of the solar atmosphere. Title: Iron Line Ratio Analysis in an Active Region Authors: Watanabe, Tetsuya; Hara, H.; Culhane, J. L.; Harra, L. K.; Doschek, G. A.; Mariska, J. T.; Young, P. R.; Hinode EIS Team Bibcode: 2007AAS...210.7204W Altcode: 2007BAAS...39..179W Increased diagnostic capability of the EIS instrument on board Hinode (Solar-B) is demonstrated with a set of iron emission lines appearing in the two EIS observing wavelengths (170 - 210 A & 250 - 290 A) and their line intensity ratios. First-light spectra of a small active region show iron lines at the ionization stages of FeVIII (185.2 A & 186.6 A) through FeXVII (204.7 A, 254.9 A, & 269.4 A). Decay phase spectra of a C-class flare confirms the presence of this higher temperature line; FeXVII at 254.9 A more clearly, as well as those lines of flare temperatures; FeXXIV (192.0 A & 255.1 A) and FeXXIII (263.8 A). Title: Initial Results On Active Region Loop Morphology From Hinode EIS And XRT. Authors: Brooks, David; Warren, H.; Young, P.; Matsuzaki, K.; Williams, D. Bibcode: 2007AAS...210.6307B Altcode: 2007BAAS...39Q.172B Theoretically, magnetic fields are expected to expand as they rise above the photosphere and into the corona, so the apparent uniform cross-sections of active region coronal loops are difficult to understand. There has been some debate in the community as to whether coronal loops really have constant cross-sections (as suggested by TRACE and SXT), or are actually unresolved and composed of expanding threads within the constant cross-section envelopes. Furthermore, loop expansion is critical to the success or failure of hydrostatic models in reproducing the observed intensities and morphology in active region loops, bright points, and the full Sun. Hinode EIS and XRT provide unprecedented spatial resolution at high temperatures that can be used to reexamine the morphology of active region loops and provide new insights. Here we present initial results from our study of active region loop widths with EIS and XRT. Title: Science With The Extreme Ultraviolet Spectrometer For Solar Orbiter Authors: Young, P. R.; EUS Science Working Group Bibcode: 2007ESASP.641E..21Y Altcode: The CCLRC Rutherford Appleton Laboratory (UK) is leading a consortium that proposes to build an ultraviolet spectrometer for Solar Orbiter provisionally called the Extreme Ultraviolet Spectrometer (EUS). The selection of wavelength bands for EUS has been re-assessed by the EUS Science Working Group in recent months and the final decision calls for three wavelength bands covering 700-800 Å, 970-1040 Å, and 1163-1265 Å. The key features of these bands are summarised here, and particular science topics that can be addressed by EUS are discussed. Title: Optical Design Of The Extreme Ultraviolet Spectrometer (EUS) On Board Solar Orbiter Authors: Middleton, K.; Da Deppo, V.; Poletto, L.; Schühle, U.; Thomas, R. J.; Young, P. R. Bibcode: 2007ESASP.641E..48M Altcode: We present optical designs for the Extreme Ultraviolet Imaging Spectrometer (EUS) proposed for Solar Orbiter. We summarise the scientific requirements for EUS and show how they translate into an instrument specification and optical design. Two design options are presented: one utilising a normal incidence telescope and one utilising a grazing incidence telescope. Both options use the same design of spectrometer, which incorporates a Toroidal Varied Line-Space (TVLS) grating, allowing high quality imaging at relatively large spectrometer magnifications. This results in a very compact yet high performance design. We give estimates of the instrument's optical performance and throughput and discuss briefly some heat management strategies. Title: MARS Valley Networks Project: Martian Valley Network Analysis Run-off or Sapping? - A WebGIS approach Authors: Luo, W.; Kitts, K. B.; Young, P.; Schwantes, F. W.; Hung, W. Bibcode: 2006AGUFMED42A..07L Altcode: We report the progress made in a two-year NASA funded EPO project, which takes advantage of the latest WebGIS technology to bring real NASA data to high school classrooms. The only requirement for the WebGIS is an Internet connection and a standard web browser allowing the widest possible accessibility. The overall goal of the project is to enhance the students' interest in science and to directly engage them in the actual process of conducting scientific research with a real scientific research question and real scientific datasets. The students will be exposed to the full process of conducting real scientific investigation: collecting evidence, analyzing data, formulating alternative hypotheses, and communicating and debating with their peers about their findings. Such opportunities are rarely available in the middle through high school level. We have set up the WebGIS (http://marsproject.niu.edu) and have completed the student and teacher tutorials. The standard-based student modules are being finalized and tested by two Master teachers this semester. A training workshop for teachers will be held Spring 2007. Approximately twenty classrooms will be participating fully by the 2007-08 school year. Title: Solar And Cosmic Ray Physics And The Space Environment: Studies For And With LISA Authors: Shaul, D. N. A.; Aplin, K. L.; Araújo, H.; Bingham, R.; Blake, J. B.; Branduardi-Raymont, G.; Buchman, S.; Fazakerley, A.; Finn, L. S.; Fletcher, L.; Glover, A.; Grimani, C.; Hapgood, M.; Kellet, B.; Matthews, S.; Mulligan, T.; Ni, W. -T.; Nieminen, P.; Posner, A.; Quenby, J. J.; Roming, P.; Spence, H.; Sumner, T.; Vocca, H.; Wass, P.; Young, P. Bibcode: 2006AIPC..873..172S Altcode: With data analysis preparations for LISA underway, there has been renewed interest in studying solar, cosmic ray and environmental physics for, and using LISA. The motivation for these studies is two fold. The primary incentive is to predict and consequently minimize the impact of disturbances associated with these factors, to maximize LISA's gravitational wave scientific yield. The second stimulus is the unique opportunity that is afforded by LISA's long-baseline 3-spacecraft configuration for studies of solar, cosmic ray and environmental physics. Here we present an overview of recent progress in these studies. Title: High-Ionization Forbidden Lines in the UV Spectrum of AG Draconis Authors: Young, P. R.; Dupree, A. K.; Espey, B. R.; Kenyon, S. J. Bibcode: 2006ApJ...650.1091Y Altcode: High-ionization forbidden lines from Ca VII, Fe VII, Mg V, Mg VI, Mg VII, and Si VII are found in recent Hubble Space Telescope STIS ultraviolet spectra of the symbiotic star AG Draconis. These species have ionization potentials between 99 and 205 eV, which are unexpected due to the high density (~1010 cm-3) of the AG Dra nebula. The identification of the Mg VII λλ2510, 2629 lines is the first in astrophysical or laboratory spectra, and revised rest wavelengths are suggested from the STIS spectra. Plasma diagnostics from Mg V-VII are applied, but do not provide a consistent constraint on temperature or density. A density >=108 cm-3 is confirmed, however. The lines show double-peaked profiles with widths ~100-160 km s-1, suggestive of an origin in an accretion disk. However, the line widths, if identified with motion in a Keplerian disk, indicate radii much smaller than sizes inferred from the line fluxes themselves. The source of these high-ionization forbidden lines remains unidentified. Title: Multi-Wavelength Investigation of a Sigmoidal Active Region Authors: Tripathi, D.; Mason, H. E.; Young, P. R. Bibcode: 2006ESASP.617E.148T Altcode: 2006soho...17E.148T No abstract at ADS Title: Java Message Service (JMS) use in the Telescope Automation and Remote Observing System (TAROS) Authors: Czezowski, A.; Green, A.; Hovey, G.; Jarnyk, M.; Nielsen, J.; Roberts, B.; Sebo, K.; Smith, D.; Vaccarella, A.; Wilson, G.; Young, P. Bibcode: 2006ASPC..351..208C Altcode: 2006adass..15..208C JMS is an enterprise messaging system, part of the Java 2 Platform, Enterprise Edition (J2EE). It provides distributed applications a method for asynchronously sending and receiveing critical data and events. It also decouples the message delivery management subsystem from the application itself. TAROS is a distributed system that will allow the Australian National University telescopes at Siding Spring Observatory to be operated automatically or interactively over the Internet. JMS technology is used throughout TAROS, providing a communication path between the TAROS back-end software components as well as between TAROS and its external clients. Title: The Solar Neon Abundance and the Standard Solar Model Authors: Young, P. R. Bibcode: 2006ESASP.617E..47Y Altcode: 2006soho...17E..47Y No abstract at ADS Title: CHIANTI-An Atomic Database for Emission Lines. VII. New Data for X-Rays and Other Improvements Authors: Landi, E.; Del Zanna, G.; Young, P. R.; Dere, K. P.; Mason, H. E.; Landini, M. Bibcode: 2006ApJS..162..261L Altcode: The CHIANTI atomic database contains atomic energy levels, wavelengths, radiative transition probabilities, and collisional excitation data for a large number of ions of astrophysical interest. CHIANTI also includes a suite of IDL routines to calculate synthetic spectra and carry out plasma diagnostics. Version 5 has been released, which includes several new features, as well as new data for many ions. The new features in CHIANTI are as follows: the inclusion of ionization and recombination rates to individual excited levels as a means to populate atomic levels; data for Kα and Kβ emission from Fe II to Fe XXIV; new data for high-energy configurations in Fe XVII to Fe XXIII; and a complete reassessment of level energies and line identifications in the X-ray range, multitemperature particle distributions, and photoexcitation from any user-defined radiation field. New data for ions already in the database, as well as data for ions not present in earlier versions of the database, are also included. Version 5 of CHIANTI represents a major improvement in the calculation of line emissivities and synthetic spectra in the X-ray range and expands and improves theoretical spectra calculations in all other wavelength ranges. Title: The Ne/O abundance ratio in the quiet Sun Authors: Young, P. R. Bibcode: 2005A&A...444L..45Y Altcode: 2005astro.ph.10264Y Context: .
Aims: .To determine the neon-to-oxygen abundance in the quiet Sun, a proxy for the photospheric abundance ratio.
Methods: .An emission measure method applied to extreme ultraviolet emission lines of Ne iv-vi and O iii-v ions observed by the Coronal Diagnostic Spectrometer on the SOHO satellite.
Results: .The average Ne/O abundance ratio in supergranule cell centre regions is 0.18± 0.05, while in supergranule network regions is 0.16± 0.04. A photospheric Ne/O ratio of 0.17± 0.05 is suggested, in good agreement with the most recent compilation of solar photospheric abundances, but discrepant with a recent Ne/O ratio derived from stellar X-ray spectra and revised neon abundances suggested from solar interior models.
Conclusions: . Title: Telescope Automation and Remote Observing System (TAROS) Authors: Wilson, G.; Czezowski, A.; Hovey, G. R.; Jarnyk, M. A.; Nielsen, J.; Roberts, B.; Sebo, K.; Smith, D.; Vaccarella, A.; Young, P. Bibcode: 2005ASPC..347..563W Altcode: 2005adass..14..563W TAROS is a system that will allow for the Australian National University telescopes at a remote location to be operated automatically or interactively with authenticated control via the internet. TAROS is operated by a Java front-end GUI and employs the use of several Java technologies - such as Java Message Service (JMS) for communication between the telescope and the remote observer, Java Native Interface to integrate existing data acquisition software written in C++ (CICADA) with new Java programs and the JSky collection of Java GUI components for parts of the remote observer client. In this poster the design and implementation of TAROS is described. Title: The element abundance FIP effect in the quiet Sun Authors: Young, P. R. Bibcode: 2005A&A...439..361Y Altcode: 2005astro.ph..3038Y The Mg/Ne abundance ratio in the quiet Sun is measured in both network and supergranule cell centre regions through EUV spectra from the Coronal Diagnostic Spectrometer on SOHO. Twenty four sets of data over the period 1996 March to 1998 June (corresponding to solar minimum and the onset of the next cycle) are studied. Emission lines of the sequences Ne IV-VII and Mg V-VIII are simultaneously analysed by comparing with theoretical emissivities from the CHIANTI database to yield the Mg/Ne abundance and emission measure over the temperature region 5.0≤log T≤ 6.1. The average enhancements over the photospheric Mg/Ne abundance are found to be 1.25± 0.10 (network) and 1.66± 0.23 (cell centres), implying that the structures making up the transition region have close-to photospheric abundances. In particular, this implies that only a small fraction of the quiet Sun can connect to the solar wind where the Mg/Ne abundance ratio is found to be factors 4-5 greater than the photospheric value. The quiet Sun spectra are also utilised to determine the coronal density and temperature, leading to average values of 2.6+0.5-0.4× 108 cm-3 and log (T/K)=5.95± 0.02. No significant trend with the rise in solar activity during 1996-98 is found for any of the derived quantities, implying that quiet Sun regions show little dependence on the solar cycle. Title: Recent developments of the CHIANTI database in the X-ray wavelength range Authors: Landi, E.; Dere, K. P.; Young, P. R.; del Zanna, G.; Mason, H. E.; Landini, M. Bibcode: 2005AIPC..774..409L Altcode: CHIANTI is a database of atomic data and transition probabilities that allows the calculation of synthetic spectra and plasma diagnostics of optically thin plasmas. It is primarily suited for wavelengths shorter than 2000 Å but in principle can also be used at longer wavelengths. In the present paper we illustrate the latest development of the CHIANTI database, that include a huge expansion of the database in the X-ray wavelength range, the renewal of several data in the EUV range, and the inclusion of ionization and recombination in the level population calculation. This enhanced database will constitute the Version 5 of CHIANTI. Title: A Far-Ultraviolet Spectroscopic Survey of Luminous Cool Stars Authors: Dupree, A. K.; Lobel, A.; Young, P. R.; Ake, T. B.; Linsky, J. L.; Redfield, S. Bibcode: 2005ApJ...622..629D Altcode: 2004astro.ph.12539D The Far Ultraviolet Spectroscopic Explorer (FUSE) ultraviolet spectra of eight giant and supergiant stars reveal that high-temperature (3×105 K) atmospheres are common in luminous cool stars and extend across the color-magnitude diagram from α Car (F0 II) to the cool giant α Tau (K5 III). Emission present in these spectra includes chromospheric H Lyβ, Fe II, C I, and transition region lines of C III, O VI, Si III, and Si IV. Emission lines of Fe XVIII and Fe XIX signaling temperatures of ~107 K and coronal material are found in the most active stars, β Cet and 31 Com. A short-term flux variation, perhaps a flare, was detected in β Cet during our observation. Stellar surface fluxes of the emission of C III and O VI are correlated and decrease rapidly toward the cooler stars, reminiscent of the decay of magnetically heated atmospheres. Profiles of the C III λ977 lines suggest that mass outflow is underway at T~80,000 K and the winds are warm. Indications of outflow at higher temperatures (3×105 K) are revealed by O VI asymmetries and the line widths themselves. High-temperature species are absent in the M supergiant α Ori. Narrow fluorescent lines of Fe II appear in the spectra of many giants and supergiants, apparently pumped by H Lyα, and formed in extended atmospheres. Instrumental characteristics that affect cool star spectra are discussed. Title: Fe VII lines in the spectrum of RR Telescopii Authors: Young, P. R.; Berrington, K. A.; Lobel, A. Bibcode: 2005A&A...432..665Y Altcode: 2004astro.ph.12157Y Thirteen transitions within the ground 3d2 configuration of Fe vii are identified in ultraviolet and optical spectra of the symbiotic star RR Telescopii obtained with the STIS instrument of the Hubble Space Telescope. The line fluxes are compared with theoretical data computed with the recent atomic data of Berrington et al., and high resolution optical spectra from VLT/UVES are used to identify blends. Seven branching ratios are measured, with three in good agreement with theory and one affected by blending. The λ5277/λ4943 branching ratio is discrepant by >3σ, indicating errors in the atomic data for the λ5277 line. A least-squares minimization scheme is used to simultaneously derive the temperature, T, and density, Ne, of the RR Tel nebula, and the interstellar extinction, E(B-V), towards RR Tel from the complete set of emission lines. The derived values are: log T/K=4.50 ± 0.23, log Ne/cm-3=7.25 ± 0.05, and E(B-V)≤ 0.27. The extinction is not well-constrained by the Fe vii lines, but is consistent with the more accurate value E(B-V)=0.109+0.052-0.059 derived here from the Ne v λ2974/λ1574 ratio in the STIS spectrum. Large differences between the K. A. Berrington et al. electron excitation data and the earlier F. P. Keenan & P. H. Norrington data-set are demonstrated, and the latter is shown to give worse agreement with observations. Title: The CHIANTI database Authors: Landi, E.; Dere, K. P.; Young, P. R.; Landini, M.; Mason, H. E.; Del Zanna, G. Bibcode: 2005HiA....13..653L Altcode: CHIANTI is a database of atomic data and transition rates necessary for calculating synthetic spectra and carrying out plasma diagnostics of astrophysical sources in the X-ray EUV and UV wavelength ranges. CHIANTI includes both line and continuum emission from all astrophysically abundant elements in the universe. All data are taken from refereed literature and are critically assessed. CHIANTI also includes a suite of IDL programs that allow spectroscopic analysis to be carried out. CHIANTI data and software are freely distributed over the internet.

In the present talk I will describe the contents of the CHIANTI database its current status and the areas where CHIANTI is being developed and I will also present a comparison of CHIANTI predictions with the X-ray emission from astrophysical sources. Title: Far Ultraviolet Spectroscopic Explorer Observations of the Symbiotic Star AG Draconis Authors: Young, P. R.; Dupree, A. K.; Espey, B. R.; Kenyon, S. J.; Ake, T. B. Bibcode: 2005ApJ...618..891Y Altcode: Spectra of the bright symbiotic star AG Draconis (BD +67°922) in the wavelength range 905-1187 Å obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) are presented. The spectra show a number of narrow, nebular emission lines, together with a uniform continuum from the hot component of the system, and numerous interstellar absorption lines. We infer the existence of Ne VIII in the AG Dra nebula through the identification of the Ne VII λ973.3 recombination line. The emission-line spectrum is dominated by intense lines of O VI but also shows weaker lines from highly ionized ions including Ne V, Ne VI, S IV, and S VI. Members of the He II Balmer series can be identified up to n=20. Lines of Fe II and Fe III fluoresced by O VI λ1032 are identified at wavelengths 1141.172 and 1142.429 Å, respectively. The emission lines are shown to be produced in a plasma with an electron temperature of 20,000-30,000 K, photoionized by the white dwarf. The Ne VI λ997/λ999 ratio shows that this ion and all others except perhaps Ne VII are formed at least 300 white dwarf radii from the white dwarf. Revised wavelengths for the Ne V 2s22p2 3P0,1-2s2p3 5S2 and Ne VI 2s22p 2P-2s2p2 4P transitions are published. Title: Recent development of the CHIANTI database in the X-ray wavelength range Authors: Landi, E.; Dere, K. P.; Mason, H. E.; Del Zanna, G.; Landini, M.; Young, P. R. Bibcode: 2004AAS...204.7310L Altcode: 2004BAAS...36R.801L CHIANTI consists of a database of critically assessed atomic data and transition rates to calculate line and continuum emission from astrophysical plasmas.

During the last year the CHIANTI database has been substantially expanded in the X-ray wavelength region by including a large number of new configurations and lines, and by including ionization and recombination processes in the level population calculations.

We will describe these improvements, the data we used, and illustrate examples of 1) their effects on predicted emissivities and on plasma diagnostics 2) applications to the study of flares in solar active regions Title: Radiative data for Fe XIII Authors: Young, P. R. Bibcode: 2004A&A...417..785Y Altcode: New radiative data for allowed and forbidden transitions between the 3s23p2, 3s3p3 and 3s23p3d configurations of Fe XIII are presented. The calculations are performed with the SSTRUCT atomic code, including 24 configurations in the model, and term energy corrections have been applied to optimise the theoretical level energies. The new data-set is compared with other calculations in the literature and also an unpublished calculation of Young that is found in the CHIANTI atomic database. Good agreement is found in all cases except with calculations of Nahar. Comparisons are also presented with laboratory and solar experimental data that demonstrate the accuracy of the present calculations. The new data are to be added to version 5 of the CHIANTI atomic database. Title: FUSE Observations of the Symbiotic Star AG Draconis Authors: Young, P. R.; Dupree, A. K.; Espey, B. R.; Kenyon, S. J.; Ake, T. B. Bibcode: 2004astro.ph..4459Y Altcode: Spectra of the bright symbiotic star AG Draconis (BD+67D922) in the wavelength range 905-1187 A obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) are presented. The spectra show a number of narrow, nebular emission lines, together with a uniform continuum from the hot component of the system, and numerous interstellar absorption lines. We infer the existence of Ne VIII in the AG Dra nebula through the identification of the Ne VII 973.3 A recombination line. The emission line spectrum is dominated by intense lines of O VI, but also shows weaker lines from highly-ionized ions including Ne V, Ne VI, S IV, S VI. Members of the He II Balmer series can be identified up to n=20. Lines of Fe II and Fe III fluoresced by O VI 1032 are identified at wavelengths 1141.172 A and 1142.429 A, respectively. The emission lines are shown to be produced in a plasma with an electron temperature of 20-30,000 K, photoionized by the white dwarf. The Ne VI 997/999 ratio shows that this ion and all others except perhaps Ne VII are formed at least 300 white dwarf radii from the white dwarf. Revised wavelengths for the Ne V 2s^2 2p^2 ^3P_0,1 - 2s 2p^3 ^5S_2 and Ne VI 2s^2 2p ^2P_J - 2s 2p^2 ^4P_J' transitions are published. Title: Intense Blinker in Active Regions Authors: Young, P. R. Bibcode: 2004ESASP.547..257Y Altcode: 2004soho...13..257Y A particular class of active region brightenings seen with the Coronal Diagnostic Spectrometer on SOHO show transition region emission lines enhanced by factors of around 1000 over quiet Sun values. The brightenings have high density ( 1012 cm-3 ) and are estimated to be around 0.1-0.2 arcsec in size. They are predominantly found in active regions whose magnetic structure is rapidly evolving. High cadence time sequences yield lifetimes of around 5 mins. Title: The element abundance FIP effect in the quiet Sun Authors: Young, P. R. Bibcode: 2004cosp...35..957Y Altcode: 2004cosp.meet..957Y The Coronal Diagnostic Spectrometer onboard SOHO is unique amongst solar spectroscopy missions in being able to study the 'FIP effect' in quiet Sun regions on the solar disk. Measurements of Mg/Ne EUV emission line ratios over a 2 year period (1996-1998) will be presented and compared with changes in the emission measure, temperature and density of the quiet Sun over this time. Supergranule cell centre and network regions will be compared and contrasted. Title: CHIANTI -- An Atomic Database for UV and X-ray Cool star spectroscopy Authors: Young, P. R.; Landi, E.; Bromage, G. E.; del Zanna, G.; Dere, K. P.; Landini, M.; Mason, H. E. Bibcode: 2003csss...12.1119Y Altcode: The CHIANTI atomic database was first released in 1996 and has since become the standard resource for the interpretation of UV spectra from the transition regions and coronae of the Sun and other cool stars. We describe the contents of the most recent release (v.3) and some of the uses that have been found for the database. Title: A Far Ultraviolet Spectroscopic Explorer Survey of Coronal Forbidden Lines in Late-Type Stars Authors: Redfield, Seth; Ayres, Thomas R.; Linsky, Jeffrey L.; Ake, Thomas B.; Dupree, A. K.; Robinson, Richard D.; Young, Peter R. Bibcode: 2003ApJ...585..993R Altcode: 2002astro.ph.11363R We present a survey of coronal forbidden lines detected in Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of nearby stars. Two strong coronal features, Fe XVIII λ974 and Fe XIX λ1118, are observed in 10 of the 26 stars in our sample. Various other coronal forbidden lines, observed in solar flares, also were sought but not detected. The Fe XVIII feature, formed at logT=6.8 K, appears to be free of blends, whereas the Fe XIX line can be corrupted by a C I multiplet. FUSE observations of these forbidden iron lines at spectral resolution λ/Δλ~15,000 provides the opportunity to study dynamics of hot coronal plasmas. We find that the velocity centroid of the Fe XVIII feature deviates little from the stellar rest frame, confirming that the hot coronal plasma is confined. The observed line widths generally are consistent with thermal broadening at the high temperatures of formation and show little indication of additional turbulent broadening. The fastest rotating stars, 31 Com, α Aur Ab, and AB Dor, show evidence for excess broadening beyond the thermal component and the photospheric vsini. The anomalously large widths in these fast-rotating targets may be evidence for enhanced rotational broadening, consistent with emission from coronal regions extending an additional ΔR~0.4-1.3R* above the stellar photosphere, or represent the turbulent broadening caused by flows along magnetic loop structures. For the stars in which Fe XVIII is detected, there is an excellent correlation between the observed Röntgensatellit (ROSAT) 0.2-2.0 keV soft X-ray flux and the coronal forbidden line flux. As a result, Fe XVIII is a powerful new diagnostic of coronal thermal conditions and dynamics that can be utilized to study high-temperature plasma processes in late-type stars. In particular, FUSE provides the opportunity to obtain observations of important transition region lines in the far-UV, as well as simultaneous measurements of soft X-ray coronal emission, using the Fe XVIII coronal forbidden line. Title: Boundary Conditions for Stellar Convection (invited review) Authors: Arnett, D.; Young, P.; Knierman, K. A.; Rigby, J. R. Bibcode: 2003ASPC..304..342A Altcode: 2003cnou.conf..342A No abstract at ADS Title: CHIANTI-An Atomic Database for Emission Lines. VI. Proton Rates and Other Improvements Authors: Young, P. R.; Del Zanna, G.; Landi, E.; Dere, K. P.; Mason, H. E.; Landini, M. Bibcode: 2003ApJS..144..135Y Altcode: 2002astro.ph..9493Y The CHIANTI atomic database contains atomic energy levels, wavelengths, radiative transition probabilities, and electron excitation data for a large number of ions of astrophysical interest. Version 4 has been released, and proton excitation data are now included, principally for ground configuration levels that are close in energy. The fitting procedure for excitation data, both electrons and protons, has been extended to allow nine-point spline fits in addition to the previous five-point spline fits. This allows higher quality fits to data from close-coupling calculations where resonances can lead to significant structure in the Maxwellian-averaged collision strengths. The effects of photoexcitation and stimulated emission by a blackbody radiation field in a spherical geometry on the level balance equations of the CHIANTI ions can now be studied following modifications to the CHIANTI software. With the addition of H I, He I, and N I, the first neutral species have been added to CHIANTI. Many updates to existing ion data sets are described, while several new ions have been added to the database, including Ar IV, Fe VI, and Ni XXI. The two-photon continuum is now included in the spectral synthesis routines, and a new code for calculating the relativistic free-free continuum has been added. The treatment of the free-bound continuum has also been updated. Title: CHIANTI - An Atomic Database for XUV Emission Lines Authors: Landi, Enrico; Dere, Ken P.; Landini, Massimo; Young, Peter R.; Mason, Helen E.; del Zanna, Giulio Bibcode: 2003IAUJD..17E..10L Altcode: CHIANTI is a database of atomic data and transition rates necessary for calculating synthetic spectra and carrying out plasma diagnostics of astrophysical sources in the X-ray EUV and UV wavelength ranges. CHIANTI includes both line and continuum emission from all astrophysically abundant elements in the universe. All data are taken from refereed literature and are critically assessed. CHIANTI also includes a suite of IDL programs that allow spectroscopic analysis to be carried out. CHIANTI data and software are freely distributed over the internet.

In the present talk I will describe the contents of the CHIANTI database its current status and the areas where CHIANTI is being developed and I will also present a comparison of CHIANTI predictions with the X-ray emission from astrophysical sources. Title: AG Draconis - a High Density Plasma Laboratory Authors: Young, Peter R.; Espey, Brian; Kenyon, Scott J.; Dupree, Andrea K. Bibcode: 2003IAUJD..20E..22Y Altcode: A program to take high resolution optical and UV spectra of the symbiotic star AG Draconis is taking place in early 2003. AG Dra has an extremely bright high density nebula ionized by a hot white dwarf and the spectra will be used as a testing ground for photoionization codes such as Cloudy and XSTAR. These codes are used routinely in the study of photoionized plasmas and there is a need for them to be accurately 'calibrated' for stable bright systems. The density of the AG Dra nebula is typical of the emission line regions of active galactic nuclei and stellar atmospheres. Several new plasma diagnostics will be available through combining FUSE (900-1200Å) and HST/STIS (1200-3000Å) UV spectra while the high resolution of these instruments will enable outflow in the nebula to be studied in unprecedented detail through emission line profiles. Title: A Far Ultraviolet Spectroscopic Explorer Survey of Late-Type Dwarf Stars Authors: Redfield, Seth; Linsky, Jeffrey L.; Ake, Thomas B.; Ayres, Thomas R.; Dupree, A. K.; Robinson, Richard D.; Wood, Brian E.; Young, Peter R. Bibcode: 2002ApJ...581..626R Altcode: We describe the 910-1180 Å spectra of seven late-type dwarf stars obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The stars include Altair (A7 IV), Procyon (F5 IV-V), α Cen A (G2 V), AB Dor (K1 V), α Cen B (K2 V), ɛ Eri (K2 V), and AU Mic (M0 V). We present line identifications, fluxes, Doppler shifts, and widths. Doppler shifts are measured with respect to heliocentric wavelength scales determined from interstellar absorption lines, and are compared with transition region line shifts seen in Hubble Space Telescope (HST) ultraviolet spectra. For the warmer stars the O VI lines extend the trend of increasing redshift with line formation temperature, but for the cooler stars the O VI line redshifts are essentially zero. The C III and O VI lines of most stars in the sample are best fit with two Gaussians, and we confirm the correlation of increasing importance of the broad component with increasing stellar activity. The nonthermal velocities of the narrow component are subsonic and exhibit a trend toward larger velocities with decreasing surface gravity, while the nonthermal velocities of the broad components show no obvious trend with stellar gravity. The C III and O VI lines of Altair show unique broad horned profiles. Two flares were observed on AU Mic. One shows increasing continuum flux to shorter wavelengths, which we interpret as free-free emission from hot plasma, and relatively narrow, redshifted C III and O VI emission. The other shows very broad line profiles. Title: AG Dra -- a high density plasma laboratory Authors: Young, Peter Bibcode: 2002hst..prop.9510Y Altcode: 2002hst..prop.5857Y A STIS observation of the symbiotic star AG Draconis yielding spectra in the range 1150--10 000 Angstrom is requested. AG Dra is a non-eclipsing binary that shows strong, narrow nebular emission lines that originate in the wind of a K giant, photoionized by a hot white dwarf. The density of the nebula is around 10^10 electrons/cm^3 and is the perfect laboratory for testing the plasma modeling codes cloudy and xstar at high densities. These codes are used for a wide range of astrophysical objects including stellar winds, accretion disks, active galactic nuclei and Seyfert galaxies, and calibrating them against high signal-to-noise spectra from comparatively simple systems is essential. AG Dra is the perfect high density laboratory for this work. In addition, many previously undetected emission lines will be found through the high sensitivity of STIS, which will allow new plasma diagnostics to be tested. These twin objectives are particularly pertinent as the high sensitivity of emphHST/COS will will permit similar high resolution spectroscopy to be applied to a whole new regime of extragalactic objects. By combining far-UV data from Ause with complementary data from STIS, we will determine ratios of emission lines from the same ion, or ions of similar ionization level. These will permit a more complete set of diagnostics than are obtainable from one instrument alone. Title: X-Ray Doppler Imaging of Stellar Coronae Authors: Brickhouse, Nancy S.; Dupree, Andrea K.; Young, Peter Bibcode: 2002APS..APRB17059B Altcode: Chandra HETG observations of the bright eclipsing contact binary 44 Boo show X-ray line profiles which are Doppler-shifted by orbital motions. The observation continuously covers 2.56 epochs. Although significant variability is found in the light curve, no clear eclipses are observed. The phase-binned line profiles, in conjunction with the X-ray light curve, constrain the coronal structures to be localized at high latitude. These observations demonstrate the power of the X-ray Doppler imaging technique. Studies of other contact binaries, and studies of RS CVn systems with future X-ray spectrometers are discussed. Title: The Capella Giants and Coronal Evolution across the Hertzsprung Gap Authors: Johnson, O.; Drake, J. J.; Kashyap, V.; Brickhouse, N. S.; Dupree, A. K.; Freeman, P.; Young, P. R.; Kriss, G. A. Bibcode: 2002ApJ...565L..97J Altcode: We present an analysis of the coronal line Fe XXI λ1354 observed in medium-resolution Hubble Space Telescope/Space Telescope Imaging Spectrograph echelle spectra of Capella obtained on 1999 September 12. These data were collected in support of a multiwavelength spectroscopic campaign designed to provide detailed temperature and density diagnostics over a wide range of temperatures, and they are accompanied by simultaneous Chandra, Extreme Ultraviolet Explorer, BeppoSAX, and Very Large Array observations. The line Fe XXI λ1354 formed at 107 K is crucial to the interpretation of these data sets since it allows the deconvolution of the coronal flux of the two binary components. While earlier observations implied comparable coronal emission from both stars, our data indicate that nearly all the Fe XXI flux in the C I/Fe XXI blend at 1354 Å arises from the rapidly rotating G1 III secondary. This suggests a significant decline in the hottest part of the corona of the G8 III primary over the past 5 years. For the first time, we can assign the variability of the high-temperature X-rays to the cooler He core burning star in the system. This result suggests that nascent coronae in the early Hertzsprung gap phase apparently do not vary and that cyclic activity and strong variability are seen only in later evolutionary stages when dynamos are more developed in deeper convective envelopes. Title: Capella: Separating the Giants Authors: Young, P. R.; Dupree, A. K. Bibcode: 2002ApJ...565..598Y Altcode: Images from the Faint Object Camera (FOC) on the Hubble Space Telescope (HST) are used to spatially separate the two giants of Capella (α Aurigae; HD 34029) for the first time at ultraviolet wavelengths. The images were obtained with broadband filters that isolate the wavelength regions 2500-3000 Å and 1300-1500 Å. The cool G8 giant is found to be weaker than the hot G1 giant by factors of around 4 and 17, respectively, in these bands. The latter factor is largely due to the much stronger G1 continuum at short wavelengths. No evidence is found for material lying between the two stars in the images. In addition, the objective prisms of the FOC were used to obtain low-resolution spectra from 1200 to 3000 Å, allowing individual emission lines from each star to be spatially separated. Cool-to-hot star ratios for the emission lines H I Lyα, O I λ1305, Si II λ1816, C II λ1335, He II λ1640, and Si IV λ1393 are presented, showing that the cool giant is weaker than the hot giant by factors of 5-10 in these lines. The O I emission is only a factor of 2.5 weaker in the cool giant, most probably resulting from fluorescence in the extended atmosphere of the cool giant. The line ratios are compared with values derived from International Ultraviolet Explorer and HST/Goddard High Resolution Spectrograph spectra, which could separate the stars spectrally but not spatially. Reasonable agreement is found although the FOC ratios generally imply lower contributions from the cool giant. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. Title: RR Tel getting under the flux limit -- an observation with FUSE Authors: Young, Peter R. Bibcode: 2002fuse.prop.C141Y Altcode: The symbiotic star RR Telescopii holds a special place amongst UV spectroscopists due to the extraordinary richness of the emission line spectrum emitted by the nebula around the system, which has proved to be an extremely fruitful laboratory for both plasma modeling and line identification. FUSE will obtain, for the first time, a high spectral resolution spectrum in the 900-1100 A region at high sensitivity. RR Tel has not previously been considered for observing with FUSE on account of the O VI line fluxes being well above the FUSE flux limits. A way to observe RR Tel safely with FUSE by only obtaining spectra through the SiC channels is outlined in the feasibility section that follows. Title: The CHIANTI Atomic Database and Instrument Calibration: a Symbiosis Authors: Mason, H. E.; Del Zanna, G.; Dere, K. P.; Landi, E.; Landini, M.; Young, P. R. Bibcode: 2002ISSIR...2..271M Altcode: 2002ESASR...2..271M; 2002rcs..conf..271M The CHIANTI atomic database comprises a comprehensive, accurate and up-to-date database of atomic parameters, necessary for emission-line spectroscopy. The suite of user-friendly software allows plasma diagnostics to be carried out. Since its release in 1996, CHIANTI has become a standard resource for the analysis of solar spectra. Accurate atomic data can provide the foundation for in-flight instrument calibrations. Conversely, an accurate instrument calibration can provide a check on atomic parameters. The internal consistency of spectral-line intensities can be used to highlight specific anomalies. In this paper, we illustrate how CHIANTI has been used to validate the calibration of solar EUV instruments: SOHO-CDS, -SUMER, -EIT and SERTS. In addition, we show how anomalous spectral-line intensities indicate the need for more accurate atomic calculations. Title: FUSE Survey of Cool Luminous Stars Authors: Dupree, A. K.; Young, P. R.; Lobel, A.; Ake, T. R.; Linsky, J. L.; Redfield, S.; FUSE Cool Star Team Bibcode: 2001AAS...199.1310D Altcode: 2001BAAS...33.1328D The FUSE telescope has been used to survey spectroscopically eight cool luminous stars (β Cet, α Ori,α Tau, α Car, β Gem, 31 Com, β Dra, α Aqr) in the spectral region λ λ 910--1180. Emission from O VI has been detected in all stars with the exception of α Ori, decreasing in surface flux across the giant branch. This demonstrates the pervasive extent of high temperature plasma ( ~ 3x 105K) to stars as late as K5 III (α Tau). Densities in the lower transition region ( ~ 70000K), as determined from C III line ratios, are on the order of 109 cm-3, with densities in the active stars 31 Com and β Cet perhaps as much as an order of magnitude higher. Emission from coronal plasma represented by Fe XVIII occurs in β Cet. Line profiles of individual species can be used to infer atmospheric heating and dynamics. Extended atmospheres are signaled by the presence of narrow Fe II emission that is fluoresced by H-Lyman α in the coolest stars including α Ori. These rich spectra document the energetics and dynamics of giant and supergiant atmospheres. Based on Guaranteed Team observations made with the NASA-CNES-CSA Far Ultraviolet Explorer which is operated for NASA by The Johns Hopkins University under NASA contract NAS5-32985. Title: The orbital light curve of aquila X-1 Authors: Robinson, E. L.; Welsh, W. F.; Young, P. Bibcode: 2001AIPC..599..902R Altcode: 2001xase.conf..902R The R-band light curve of the X-ray nova/neutron-star binary Aql X-1 is dominated by ellipsoidal variations when it is at quiescence, although the ellipsoidal variations are severely distorted and have unequal maxima. The peak-to-peak amplitude of the variations is ~ 0.25 mag. The orbital period measured from the ellipsoidal variations is consistent with the 18.95 hr period measured by Chevalier & Ilovaisky (1998); and the orbital inclination must be greater than 36°, and probably lies between 36° and 55°. During outbursts the light curve of Aql X-1 is dominated by the ``reflection effect,'' that is, by heating of the side of the companion star facing the neutron star. . Title: A Survey of Nearby Cool Dwarf Star Spectra Obtained by FUSE Authors: Redfield, S.; Linsky, J. L.; Dupree, A. K.; Young, P. R.; Lobel, A.; Ake, T. B.; FUSE Cool Star Team Bibcode: 2001AAS...199.1312R Altcode: 2001BAAS...33.1329R We present the cool star dwarf spectra obtained by the FUSE Science Team using the Far Ultraviolet Spectroscopic Explorer (FUSE). The survey includes the stars α Aql, α Cen A, α Cen B, ɛ Eri, AU Mic, and AB Dor. The spectral range extends from 900 to 1200 ~Å, at a spectral resolution of λ /Δ λ ~ 20,000. Numerous emission lines are present and identified. Lines of particular interest, such as C III (977 Å), O VI (1032 and 1038 Å), and the Lyman series, are present in all stars and studied in detail. The forbidden coronal Fe XVIII (975 Å) line is present in some spectra and is useful in studying the dynamics of the 107 K coronal plasma. Absorption by warm Local Interstellar Medium (LISM) gas is visible in several lines, such as C III (977 Å) and C II (1037 Å). Combined with LISM absorption studies of the same stars at longer wavelengths (ie. using spectrographs aboard the Hubble Space Telescope (HST)), the FUSE LISM absorption can provide important insights into the structure of the nearby warm ISM. This atlas of nearby cool stars in the far-ultraviolet provides important information pertaining to the atmospheres of dwarf stars and will be a useful tool in planning future observations of cool stars. This work is based on data obtained for the Guaranteed Time Team by the NASA-CNES-CSA FUSE mission operated by the Johns Hopkins Observatory. Financial support to U.S. participants has been provided by NASA contract NAS5-32985. Title: X-Ray Doppler Imaging of Stellar Coronae Authors: Brickhouse, N. S.; Dupree, A. K.; Young, P. R. Bibcode: 2001AAS...19911202B Altcode: 2001BAAS...33Q1478B Chandra HETG observations of the bright eclipsing contact binary 44 Boo show X-ray line profiles which are Doppler-shifted by orbital motions. The observation continuously covers 2.56 epochs. Although significant variability is found in the light curve, no clear eclipses are observed. The phase-binned line profiles, in conjunction with the X-ray light curve, constrain the coronal structures to be localized at high latitude. These observations demonstrate the power of the X-ray Doppler imaging technique. Studies of other contact binaries, and studies of RS CVn systems with future X-ray spectrometers are discussed. Title: A Relationship Between Transition Region Brightenings, Abundances, and Magnetic Topology Authors: Fletcher, Lyndsay; López Fuentes, Marcelo C.; Mandrini, Cristina H.; Schmieder, Brigitte; Démoulin, Pascal; Mason, Helen E.; Young, Peter R.; Nitta, Nariaki Bibcode: 2001SoPh..203..255F Altcode: We present multi-instrument observations of active region (AR) 8048, made between 3 June and 5 June 1997, as part of the SOHO Joint Observing Program 33. This AR has a sigmoid-like global shape and undergoes transient brightenings in both soft X-rays and transition region (TR) lines. We compute a magneto-hydrostatic model of the AR magnetic field, using as boundary condition the photospheric observations of SOHO/MDI. The computed large-scale magnetic field lines show that the large-scale sigmoid is formed by two sets of coronal loops. Shorter loops, associated with the core of the SXT emission, coincide with the loops observed in the hotter CDS lines. These loops reveal a gradient of temperature, from 2 MK at the top to 1 MK at the ends. The field lines most closely matching these hot loops extend along the quasi-separatrix layers (QSLs) of the computed coronal field. The TR brightenings observed with SOHO/CDS can also be associated with the magnetic field topology, both QSL intersections with the photosphere, and places where separatrices issuing from bald patches (sites where field lines coming from the corona are tangent to the photosphere) intersect the photosphere. There are, furthermore, suggestions that the element abundances measured in the TR may depend on the type of topological structure present. Typically, the TR brightenings associated with QSLs have coronal abundances, while those associated with BP separatrices have abundances closer to photospheric values. We suggest that this difference is due to the location and manner in which magnetic reconnection occurs in two different topological structures. Title: X-Ray Doppler Imaging of 44i Bootis with Chandra Authors: Brickhouse, N. S.; Dupree, A. K.; Young, P. R. Bibcode: 2001ApJ...562L..75B Altcode: 2001astro.ph.10560B Chandra High-Energy Transmission Grating observations of the bright eclipsing contact binary 44i Bootis show X-ray line profiles that are Doppler-shifted by orbital motions. The X-ray emission spectrum contains a multitude of lines superposed on a weak continuum, with strong lines of O VIII, Ne X, Fe XVII, and Mg XII. The profiles of these lines from the total observed spectrum show Doppler-broadened widths of ~550 km s-1. Line centroids vary with orbital phase, indicating velocity changes of greater than 180 km s-1. The first-order light curve shows significant variability but no clear evidence for either primary or secondary eclipses. Flares are observed for all spectral ranges; additionally, the light curve constructed near the peak of the emission measure distribution [Te=(5-8)×106 K] shows quiescent variability as well as flares. The phase dependences of line profiles and light curves together imply that at least half of the emission is localized at high latitude. A simple model with two regions on the primary star at relatively high latitude reproduces the observed line profile shifts and quiescent light curve. These first clear X-ray Doppler shifts of stellar coronal material illustrate the power of Chandra. Title: Far Ultraviolet Spectroscopic Explorer Observations of Capella Authors: Young, P. R.; Dupree, A. K.; Wood, B. E.; Redfield, S.; Linsky, J. L.; Ake, T. B.; Moos, H. W. Bibcode: 2001ApJ...555L.121Y Altcode: Far Ultraviolet Spectroscopic Explorer observations of the binary system Capella reveal a rich emission-line spectrum containing neutral and ionic species, among them H I, O I, C III, O VI, S VI, Ne V, and Ne VI. In addition, Fe XVIII λ974.85, formed at temperatures of ~6×106 K, is detected. Whereas the strong transition region lines principally come from the G1 giant, consistent with results from previous ultraviolet observations, Fe XVIII is formed largely in the G8 giant atmosphere. Line ratios from C III suggest densities of (2-8)×1010 cm-3, although anomalous line profiles of the 1176 Å transition may signal optical depth effects. Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer, which is operated for NASA by Johns Hopkins University under NASA contract NAS5-32985. Title: Detection of Chlorine Ions in the Far Ultraviolet Spectroscopic Explorer Spectrum of the Io Plasma Torus Authors: Feldman, Paul D.; Ake, Thomas B.; Berman, Alice F.; Moos, H. Warren; Sahnow, David J.; Strobel, Darrell F.; Weaver, Harold A.; Young, Peter R. Bibcode: 2001ApJ...554L.123F Altcode: The spectrum of the Io plasma torus in the range of 995-1187 Å was recorded at 0.26 Å resolution by the Far Ultraviolet Spectroscopic Explorer (FUSE) on 2000 January 20. Five orbits of data were obtained in point-and-shoot mode (no tracking of the moving target), with the east ansa of the torus initially centered in the 30''×30'' aperture of the FUSE LiF spectrographs yielding a total observation time of 3405 s. The spectral resolution exceeds by a factor of 10 that of the data obtained by the Hopkins Ultraviolet Telescope (HUT) during the Astro-1 mission. This region of the spectrum is dominated by resonance multiplets of S III and S IV, whose multiplet structures are nearly completely resolved, as well as numerous S II multiplets originating on the 2Do state of the ground configuration. Weak emission from a few lines of the resonance multiplets of Cl III and Cl II is detected at or above the 3 σ level, Cl III being stronger with two components roughly one-tenth the brightness of the main components of S III λ1018. We derive an abundance of Cl+2 of 3% relative to S+2, leading to an overall chlorine ion abundance in the torus of ~1%. The ratio of S IV to S III brightness is about twice that observed by HUT, which, when the different slit geometries are accounted for, supports the earlier analysis that S IV emissions originate from a region more extended out of the centrifugal plane than the S III emissions. Title: CHIANTI-An Atomic Database for Emission Lines. IV. Extension to X-Ray Wavelengths Authors: Dere, K. P.; Landi, E.; Young, P. R.; Del Zanna, G. Bibcode: 2001ApJS..134..331D Altcode: CHIANTI provides a database of atomic energy levels, wavelengths, radiative transition probabilities, and electron excitation data for a large number of ions of astrophysical interest. It also includes a suite of Interactive Data Language programs to calculate optically thin synthetic spectra and to perform spectral analysis and plasma diagnostics. This database allows the calculation of theoretical line emissivities necessary for the analysis of optically thin emission-line spectra. The first version (1.01) of the CHIANTI database was released in 1996 and published by Dere et al. in 1997 as Paper I in this series. The second version, released in 1999 by Landi et al., included continuum emission and data for additional ions. Both versions of the CHIANTI database have been used extensively by the astrophysical and solar communities to analyze emission-line spectra from astrophysical sources. Now the CHIANTI database has been extended to wavelengths shorter than 50 Å by including atomic data for the hydrogen and helium isoelectronic sequences, inner-shell transitions and satellite lines, and several other ions. In addition, some of the ions already present in the database have been updated and extended with new atomic data from published calculations. Title: CHIANTI - an atomic database for emission lines, Paper 4: Extension to X-ray Wavelengths Authors: Dere, K. P.; Landi, E.; Young, P. R.; Del Zanna, G. Bibcode: 2001AGUSM..SP21B08D Altcode: CHIANTI provides a database of atomic energy levels, wavelengths, radiative transition probabilities and electron excitation data for a large number of ions of astrophysical interest. It also includes a suite of Interactive Data Language (IDL) programs to calculate optically thin synthetic spectra and to perform spectral analysis and plasma diagnostics. This database allows the calculation of theoretical line emissivities necessary for the analysis of optically thin emission line spectra. The first version of the CHIANTI database was released in 1996 (Dere et al., 1996). The second version, released in 1999, included continuum emission and data for additional ions (Landi et al. 1999). Both versions of the CHIANTI database have been used extensively by the astrophysical and solar communities to analyze emission line spectra from astrophysical sources. Now the CHIANTI database has been extended to wavelengths shorter than 50Å by including atomic data for the hydrogen and helium isoelectronic sequences, inner-shell transitions and satellite lines and several other ions. In addition, some of the ions already present in the database have been updated and extended with new atomic data from published calculations. Title: FUSE Observations of Capella Authors: Young, P. R.; Dupree, A. K.; Wood, B. E.; Redfield, S.; Linsky, J. L.; Ake, T. B.; Moos, H. W. Bibcode: 2001astro.ph..3261Y Altcode: Far Ultraviolet Spectroscopic Explorer FUSE observations of the bright binary system Capella (Alpha Aurigae; G1 III + G8 III) reveal a rich emission line spectrum containing neutral and ionic species, among them H I, O I, C III, O VI, S VI, Ne V and Ne VI. In addition the Fe XVIII 974.85 A line, formed at temperatures of approx. 6 x 10^6 K, is detected. Whereas the chromospheric and transition region emission is dominated by that from the G1 giant, consistent with results from previous ultraviolet observations, Fe XVIII is formed largely in the G8 giant atmosphere. Line ratios from C III suggest densities of 2-8 x 10^10 cm^-3, although anomalous line profiles of the 1176 transition may signal optical depth effects. The hydrogen Lyman series, detected for the first time, displays asymmetric emission consistent with an expanding atmosphere. Title: AG Draconis (BD +67 922) Follow-up Authors: Young, Peter Bibcode: 2001fuse.prop.P248Y Altcode: AG Draconis is a symbiotic star consisting of a K giant and white dwarf. The UV is dominated by emission lines from a nebula believed to be around the white dwarf. AG Dra was observed by FUSE on 16-March-2000 as part of the science verification program for FUSE. This short (~2400s) observation produced a high quality spectrum revealing emission lines from several species, including O VI, Ne V, Ne VI, S IV, S VI and He II. A further observation of AG Dra is planned to determine the geometry of the nebula, attribute the wind to one of the two stars, and to obtain a full exposure in the SiC channels which will be needed to obtain a density for the nebula. Title: 44i Bootis (HD 133640) Authors: Young, Peter Bibcode: 2001fuse.prop.P247Y Altcode: 44i Boo is a W UMa type contact binary at a distance of 12.8 pc with an orbital period of 6.4 hours and an inclination of 72.8 degrees, so that there are two eclipses per orbit. X-ray and UV emission from highly-ionised ions have revealed that 44i Boo exhibits a corona, but that the emission levels are below those of rapidly rotating single stars or short-period, detached binaries, indicating that the dynamo is being inhibited by the physics associated with the contact. By categorising in detail the nature of the corona of 44i Boo, one may shed light on how the magnetic dynamo operates in stars. With FUSE it will be possible to use the high spectral resolution and sensitivity of the instrument to monitor line fluxes and profiles of the strong C III 977 and O VI 1032 emission lines during the orbit, as well as use the temperature coverage of these and weaker lines to compare with the atmospheric models made with previous instruments. Title: CDS UV Brightenings Explained by Quasi-separatrices and Bald Patches in an S-shape active region Authors: Schmieder, B.; Démoulin, P.; Fletcher, L.; López Fuentes, M. C.; Mandrini, C. H.; Mason, H. E.; Young, P. R.; Nitta, N. Bibcode: 2001IAUS..203..314S Altcode: We present multi-instrument observations of AR 8048, made between June 3 and June5 1997 as part of SoHO JOP033. This active region has a sigmoid-like global shape and undergoes transient erupting phenomena which releases the stored energy. Using a force free field approach, we defined coronal magnetic field lines which fit with the observations. The large-scale magnetic field lines confirms the sigmoid characteristics of the active region. The study in 3D of the configuration explained where and how the energy is released at different places. The Ne VI brightenings correspond to the location of tangent to the photosphere field lines, named "bald patch", they are localized in the low transition region and represent feet of field lines. The Si XII brightenings at coronal temperature are at the top of coronal loops joining quasi-separatrices. Title: A FUSE Observation of the Symbiotic Star AG Draconis Authors: Young, P. R.; Dupree, A. K.; Kenyon, S. J.; Espey, B.; Ake, T. B. Bibcode: 2000AAS...197.0806Y Altcode: 2000BAAS...32.1406Y; 2000AAS...197..806Y AG Draconis (BD+67o922) is a yellow symbiotic star, consisting of a K0--K3 giant and hot compact object, thought to be a white dwarf. The hot star photoionizes the wind of the giant, giving a dense nebula rich in ionized species. The system undergoes increases in brightness by up to 3 magnitudes at irregular intervals, a phenomenon thought to be due to the triggering of nuclear burning on the hot star after the accretion of a critical mass of material from the giant wind. The Far Ultraviolet Spectroscopic Explorer (FUSE) satellite observed AG Dra in March 2000 during a quiescent period. The spectrum covered the range 905--1187 Å at a spectral resolution of ~ 15--20,000, and exhibits a number of emission lines from highly-ionised species, a continuum from the hot star, and absorption lines from the interstellar medium. The O 6 λ λ 1032, 1038 emission lines dominate the spectrum, with the λ 1032 line showing evidence of a warm wind. Other species identified include Ne 5, Ne 6, S 4, S 6 and the He 2 Balmer lines. These lines help constrain the radiation field experienced by the nebula, and also the degree of extinction along the line of sight to AG Dra. Measurements of the absorption lines of molecular hydrogen and the atomic species are used to infer properties of the interstellar medium in the direction of AG Dra. FUSE is a NASA Origins mission operated by the Johns Hopkins University. Funding for this work is provided through NASA contract NAS-532985. Title: FUSE Observations of K--M Stars Authors: Ake, T. B.; Dupree, A. K.; Linsky, J. L.; Harper, G. M.; Young, P. R. Bibcode: 2000AAS...19712903A Altcode: 2001BAAS...33Q.712A As part of the FUSE PI program, a representative sample of cool stars is being surveyed in the LWRS (30 x 30 arcsec) aperture. We report on recent observations of three late-type stars, AU Mic (HD 197481, M0 Ve), β Gem (HD 62509, K0 IIIb), and α Ori (HD 39801, M1-2 Ia--Iab). AU Mic and β Gem show strong emission lines of O VI 1032/1037 and C III 977/1176 and weaker lines of C II, N II, N III, S IV, Si III, Si IV, and perhaps Fe III. AU Mic has evidence of He II and S III emission, and β Gem shows S I emission. Differences are seen in line ratios and line profiles between these stars. In α Ori, these features are very weak or non-existent, and Fe II fluorescent lines in the 1100-1150 Å region, pumped by H I Lyman α , are present. Several emission lines are still unidentified in all spectra. Prospects for future cool star observations will be discussed. This work is based on data obtained for the Guaranteed Time Team by the NASA-CNES-CSA FUSE mission operated by the Johns Hopkins University. Financial support to U. S. participants has been provided by NASA contract NAS5-32985. Title: FUSE Observations of Luminous Cool Stars Authors: Dupree, A. K.; Young, P. R.; Ake, T. B. Bibcode: 2000AAS...197.4417D Altcode: 2000BAAS...32.1474D Luminous cool stars can address the evolution of magnetic activity and the dynamics of stellar winds and mass loss. The region of yellow supergiants in the HR diagram contains stars of intermediate mass both with coronas and those possessing a hot outer atmosphere in the presence of a strong wind (the ``hybrid'' stars). These hybrid objects hold particular significance for evolution studies because they represent the physically important connection between solar-like stars (with coronas and fast winds of low-mass loss rate) and the cool supergiant stars (Alpha Ori-like) with cool outer atmospheres and massive winds. The Far Ultraviolet Spectroscopic Explorer (FUSE) measured the chromospheric and transition region emissions of the bright G2 Ib supergiant Beta Draconis (HD 159181) on 9 May 2000. Two exposures through the large aperture totaled 7695 s and were obtained in all channels covering the region λ λ 912-1180. Emission from chromospheric and transition region ions (C III, O VI, Si III, S IV, S VI) is detected along with a number of low ion stages. Profiles of strong lines are asymmetric suggesting the presence of a wind. A short exposure (3260 s) of Alpha Aquarii (HD 209750), a hybrid supergiant also of spectral type G2 Ib was obtained June 29, 2000. Dynamics of the atmospheres can be inferred from line profiles. The atmospheric temperature distribution, densities, and scale sizes can be evaluated from line fluxes to characterize the differences between a coronal star and a hybrid supergiant. FUSE is a NASA Origins mission operated by The Johns Hopkins University. Funding for this research is provided through NASA Contract NAS-532985. Title: Observational Tests and Predictive Stellar Evolution Authors: Young, P.; Mamajek, E.; Arnett, D.; Liebert, J. Bibcode: 2000AAS...19711401Y Altcode: 2000BAAS...32.1596Y We present comparisons between the detached, double-line eclipsing binaries of Andersen (1991), which have precisely determined masses and radii, and stellar evolution models produced with the TYCHO code. A set of eighteen binary systems were chosen which cover a range of mass from 22.89 to 0.96 Msol. The error of the models in Teff, luminosity and the time difference (between the best fit models for each member of a pair) had dispersions of ~ 3%, 6%, and 10%, respectively, without optimization of parameters. This indicates that the contributions to observable parameters from poorly constrained (either theoretically or observationally) effects such as abundances, rotation and convective overshooting are of order a few percent for the majority of stars. The outlying stars provide candidates for observations which may shed light on these effects. Pre-MS models matched EK Cep B, a known post-T Tauri star and the PV Cas system, comprised of peculiar late B/early A stars which have historically proven difficult to fit (Pols et al., 1997). Estimates of the time until Roche lobe overflow identified five systems which may begin mass transfer when < 10% older than their current age. The primary of zeta Phe in particular appears to be especially close to Roche lobe overflow, which may explain the difficulty in fitting conventional stellar models to the system. Finally, the structural k constants were calculated from the best fit models for a subset of eleven systems with published apsidal motions. This work was supported in part by the DOE, grant number DE-FG03-98DP00214/A001. Title: Detection of Chlorine Ions in the FUSE Spectrum of the Io Plasma Torus Authors: Feldman, P. D.; Ake, T. B.; Berman, A. F.; Moos, H. W.; Sahnow, D. J.; Strobel, D. F.; Weaver, H. A.; Young, P. R.; FUSE Solar System Team Bibcode: 2000DPS....32.3401F Altcode: 2000BAAS...32.1054F The spectrum of the Io plasma torus in the range 995--1087 Å was recorded at ~0.3 Å resolution by the Far Ultraviolet Spectroscopic Explorer (FUSE) on January 20, 2000. Five orbits of data were obtained in point-and-shoot mode (no tracking of the moving target) with the East ansa of the torus initially centered in the 30'' x 30'' aperture of the FUSE LiF spectrographs yielding a total observation time of 3405 seconds. The spectral resolution exceeds by a factor of ten that of the data obtained by the Hopkins Ultraviolet Telescope (HUT) during the Astro-1 mission (Moos et al., ApJ 382, L105, 1991). This region of the spectrum is dominated by resonance multiplets of S 3 at 1018 Å and S 4 at 1070 Å, whose multiplet structure is nearly completely resolved, as well as numerous S 2 multiplets originating on the 2D^o state of the ground configuration. Weak emission from the resonance multiplets of Cl 3 at 1011 Å and Cl 2 at 1071 Å are seen, the former being stronger with two components roughly one-tenth the brightness of the main components of S 3 λ 1018. Although collision strengths for Cl ions are not readily available, the isoelectronic relationship between S and Cl ions suggests an abundance of Cl+2 of a few percent relative to S+, similar to the result found by Küppers and Schneider (GRL 27, 513, 1999) for Cl+ from optical spectra. The ratio of S 4 to S 3 brightness is about twice that observed by HUT, which when the different slit geometries are accounted for supports the analysis by Hall et al. (ApJ 420, L45, 1994) that S 4 emissions originate from a region more extended out of the centrifugal plane than the S 3 emissions. We also note the detection of weak He 2 emission at 1025.3 Å, on the blue wing of geocoronal Lyman-β . The origin of the helium ions is not clear at this time. This work is based on data obtained for the Guaranteed Time Team by the NASA-CNES-CSA FUSE mission operated by the Johns Hopkins University. Financial support to U. S. participants has been provided by NASA contract NAS5-32985. Title: Far Ultraviolet Spectroscopic Explorer Observations of the Active Cool Star AB Doradus Authors: Ake, T. B.; Dupree, A. K.; Young, P. R.; Linsky, J. L.; Malina, R. F.; Griffiths, N. W.; Siegmund, O. H. W.; Woodgate, B. E. Bibcode: 2000ApJ...538L..87A Altcode: Far-ultraviolet spectra were obtained of the active cool star AB Doradus (HD 36705) during the calibration and checkout period of the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations in this early phase of the mission were taken at a resolving power of 12,000-15,000 (~20-25 km s-1) and covered the spectral range 905-1187 Å. The integrated spectrum exhibits strong, rotationally broadened stellar emission from C III (λλ977, 1175) and O VI (λλ1032, 1037) and many weaker lines. Strong emission lines of C III and O VI exhibit broad wings. The C III λ977 profile shows blueshifted absorption at ~30 km s-1, and C II λ1036 absorption appears superposed on emission in the wing of O VI λ1037. Rotational modulation of C III and O VI is present, in harmony with its photometric variability. Flares were detected in the brightest lines, and subexposures were analyzed to examine flux and profile variations. Downflows that extend to 600 km s-1 during a flare are found in the O VI profiles. These early observations demonstrate that FUSE will be an exceptional instrument for studying chromospheres in cool stars. Title: FUSE Observations of the Active Cool Star AB Doradus Authors: Ake, T. B.; Dupree, A. K.; Young, P. R.; Linsky, J. L.; Malina, R. F.; Griffiths, N. W.; Siegmund, O. H. W.; Woodgate, B. E. Bibcode: 2000astro.ph..6117A Altcode: Far ultraviolet spectra were obtained of the active cool star AB Doradus (HD 36705) during the calibration and checkout period of the FUSE satellite. Observations in this early phase of the mission were taken at a resolving power of 12000-15000 (~20-25 km/s) and covered the spectral range 905-1187 A. The integrated spectrum exhibits strong, rotationally broadened stellar emission from C III (977, 1175) and O VI (1032, 1037), and many weaker lines. Strong emission lines of C III and O VI exhibit broad wings. The C III 977 profile shows blue-shifted absorption at ~30 km/s and C II 1036 absorption appears superposed on emission in the wing of O VI 1037. Rotational modulation of C III and O VI is present, in harmony with its photometric variability. Flares were detected in the brightest lines and subexposures were analyzed to examine flux and profile variations. Downflows that extend to 600 km/s during a flare are found in the O VI profiles. These early observations demonstrate that FUSE will be an exceptional instrument for studying chromospheres in cool stars. Title: Atomic data from the IRON Project. XL. Electron impact excitation of the Fe XIV EUV transitions Authors: Storey, P. J.; Mason, H. E.; Young, P. R. Bibcode: 2000A&AS..141..285S Altcode: We calculate collision strengths and thermally averaged collision strengths for electron excitation between the forty energetically lowest levels of Fe13+. The scattering calculation is more complete than any previous work on this ion and significant differences are found in the excitation rates for many of the extreme ultra-violet (EUV) transitions, compared to earlier work. A detailed comparison is made between predicted line intensity ratios and those observed in solar coronal spectra which shows that several outstanding discrepancies are resolved by the new atomic data. Title: Capella: Separating the Giants Authors: Young, P. R.; Dupree, A. K.; Gilliland, R. L. Bibcode: 1999AAS...195.7604Y Altcode: 1999BAAS...31.1483Y Faint Object Camera (FOC) images from the Hubble Space Telescope are presented showing a clean spatial separation of the two giants in the Capella system (α Aur, HD 34029). These images were taken at elongation (Dec. 21, 1997) when the apparent separation of the stars, 55 milliarcseconds, corresponded to 4 pixels in the FOC image. Careful use of the objective prism mode of the FOC yielded ultraviolet spectra with dispersion perpendicular to the axis of separation of the two stars. The relative flux contributions to prominent UV emission lines such as O I λ 1305, C II λ 1335 and Si IV λ 1397 can then be derived. This direct measurement of each star's emission can be compared to the total spectrum as obtained by STIS at a similar phase (Sept. 12, 1999) where multiple gaussian fitting must be invoked to separate the individual contributions. The relation of these ratios to the known evolutionary states of the two stars, and the consequences for theories of stellar magnetic dynamos are discussed. This research is supported in part by an STScI Grant to SAO. Title: CHIANTI: A database for astrophysical emission line spectroscopy Authors: Del-Zanna, Giulio; Young, Peter; Dere, Ken; Landini, Massimo; Landi, Enrico; Mason, Helen Bibcode: 1999ascl.soft11004D Altcode: CHIANTI consists of a critically evaluated set of atomic data necessary to calculate the emission line spectrum of astrophysical plasmas. The data consists of atomic energy levels, atomic radiative data such as wavelengths, weighted oscillator strengths and A values, and electron collisional excitation rates. A set of programs that use these data to calculate the spectrum in a desired wavelength range as a function of temperature and density are also provided. These programs have been written in Interactive Data Language (IDL) and descriptions of these various programs are provided on the website. Title: Temperature and density in a polar plume - measurements from CDS/SOHO Authors: Young, P. R.; Klimchuk, J. A.; Mason, H. E. Bibcode: 1999A&A...350..286Y Altcode: A detailed analysis of a particularly intense polar plume observed on the 25th of October, 1996, by the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO) is presented. Above the limb, emission measure distributions derived for both the plume and a section of coronal hole background are found to be sharply peaked at approximately 1.0-1.1 million degrees in both regions. The temperature rises with height in the background, but no evidence is found for a rising temperature in the plume. The density of the background is approximately 10(8) electrons/cm(3) and falls with height. In the plume the density is between 3.8 and 9.5x 10(8) electrons/cm(3) , and exhibits no decrease with height up to 70 000 km. The plume base is visible on the solar surface and shows a strong brightening lying directly below the main body of the plume. This brightening has a temperature of 2 000 000 K, and a density of 2.5-5.6x 10(9) electrons/cm(3) . Images from lines formed at different temperatures suggest that the morphology of the base is consistent with an emerged bipole in a region of unipolar magnetic flux. A measurement of the Mg/Ne relative abundance is made at two transition region brightenings at the base of the plume. An enhancement of only 1.5 is found over the photospheric value. Considerations of the geometry of both the high temperature brightening at the base of the plume and the off-limb section give filling factors of 0.5 and 1.0, respectively. Title: SunBlock '99: Young Scientists Investigate the Sun Authors: Walsh, R. W.; Pike, C. D.; Mason, H.; Young, P.; Ireland, J.; Galsgaard, K. Bibcode: 1999ESASP.446..693W Altcode: 1999soho....8..693W SunBlock `99 is a Web-based Public Understanding of Science and educational project which seeks to present the very latest solar research as seen through the eyes of young British scientists. These ``solar guides'' discuss not only their scientific interests, but also their extra-curricular activities and the reasons they chose scientific careers; in other words the human face of scientific research. The SunBlock '99 pages gather a range of solar images and movies from current solar space observatories and discuss the underlying physics and its relationship to the school curriculum. The instructional level is pitched at UK secondary school children (aged 13-16 years). It is intended that the material should not only provide a visually appealing introduction to the study of the Sun, but that it should help bridge the often wide gap between classroom science lessons and the research scientist `out in the field'. SunBlock '99 is managed by a team from the Rutherford Appleton Laboratory and the Universities of St Andrews and Cambridge, together with educational consultants. The production has, in part, been sponsored by PPARC and the Millennium Mathematics Project. Web site addresss: http://www.sunblock99.org.uk Title: Searching for Sigmoids in SOHO/CDS Authors: Gibson, Sarah; Mason, Helen; Pike, Dave; Young, Peter Bibcode: 1999ESASP.446..331G Altcode: 1999soho....8..331G Sigmoidal structures observed in X-rays have been shown to be precursors to CMEs, existing in some cases for several days before an eruption (Sterling and Hudson 1997,ApJ,491,L55; Canfield et al, 1999, GRL, 26, 6, 627). While these S-shaped structures are most apparent in X-ray active region observations, they may be manifestations of a more general helical magnetic structure having observational signatures at other wavelengths. We will present preliminary results of a survey search for sigmoidal structures and other CME tracers in archived SOHO/CDS data for a series of active regions known to contain erupting sigmoidal structures in X-ray observations. We are particularly interested in determining the relative locations and temperatures of these tracers, and will see to what extent the data answers questions such as, if S shapes are observed at different wavelengths do they line up, or is there a spatial displacement and/or rotation of angle of S that corresponds with height/temperature variation ? How does the appearance of the region vary over the lifetime of the observed x-ray sigmoidal structure ? After an eruption, how much if any of the S shape remains, and at what spatial and spectral locations ? We will use the results of this comparison survey to consider what the implications are for the underlying magnetic field structure, and the location and variation of heating throughout it. Title: Electron density and temperature structure of two limb active regions observed by SOHO-CDS Authors: Mason, H. E.; Landi, E.; Pike, C. D.; Young, P. R. Bibcode: 1999SoPh..189..129M Altcode: The analysis of two active regions on the limb using observations from SOHO-CDS allows us to determine the electron density and temperature distribution of the coronal emission. We find that the active regions have hot cores (3×106 K) with larger cooler (106 K) loop structures extending above the limb. The electron number density, determined using the Si X diagnostic line ratio, is found to be highest in the active region core (greater than 2.3×109 cm−3). Electron number density values are determined for a range of spectral lines from different ions and are found to increase with temperature between 0.8 and 2.5×106 K. These results are consistent with recent models of enhanced heating along the compact core of active regions, where the magnetic field shear is strongest. Title: Temperature and density in coronal holes-results from CDS/SOHO Authors: Young, Peter R.; Esser, Ruth Bibcode: 1999AIPC..471..273Y Altcode: 1999sowi.conf..273Y The high speed solar wind stream comes from coronal hole regions, and it is thought that non-plume areas may provide the dominant contribution. Constraints on density and temperature in these regions are extremely important for understanding the heating and acceleration of the solar wind. Measurements are presented here from the Coronal Diagnostic Spectrometer (CDS) on SOHO, which can resolve spectral and spatial dimensions and so allow the study of individual features on the solar surface. Title: CHIANTI - an atomic database for emission lines. III. Continuum radiation and extension of the ion database Authors: Landi, E.; Landini, M.; Dere, K. P.; Young, P. R.; Mason, H. E. Bibcode: 1999A&AS..135..339L Altcode: CHIANTI provides a database of atomic energy levels, wavelengths, radiative transition probabilities and electron excitation data for a large number of ions of astrophysical interest. This database allows the calculation of theoretical line emissivities necessary for the analysis of optically thin emission line spectra, and includes also a suite of IDL (Interactive Data Language) programs to calculate optically thin synthetic spectra and to perform spectral analysis and plasma diagnostics. The first version (1.0) of the CHIANTI database was released in 1996 te[(Dere et al. 1997)]{Der97} and has been extensively used for analysis of line spectra from astrophysical sources by the scientific community. The present paper describes the first major update to the CHIANTI database which will subsequently be labeled version 2.0. The update consists of the addition of a large number of new ions, the revision of existing data for some ions and the inclusion of an IDL procedure to calculate the continuum. The CHIANTI atomic database and supporting IDL routines are freely available through the internet. Title: Comparing Quiet Sun and Coronal Hole Regions with CDS/SOHO Authors: Young, P. R.; Esser, R. Bibcode: 1999SSRv...87..345Y Altcode: Spectra from the Coronal Diagnostic Spectrometer on board SOHO are used to compare density and temperature in coronal hole and quiet Sun regions. Title: Ellipsoidal Variations in the Soft X-Ray Transient AQL X-1 Authors: Young, P.; Welsh, W. F.; Robinson, E. L. Bibcode: 1998AAS...193.4308Y Altcode: 1998BAAS...30.1314Y We have obtained 7 nights of R and I band CCD photometry of the soft X-ray transient Aql X-1. The data were obtained in 1998 June with the 2.1m telescope at McDonald Observatory under good conditions (dark time, 1--2 arcsec seeing). Aql X-1 was in a quiescent state throughout the observations. The images clearly show that a nearby, faint star is blended with Aql X-1. The data were therefore reduced with the point--spread function fitting routines in IRAF/DAOPHOT. We find the amplitude of the variations to be very small. The small amplitude of the ellipsoidal variations places a tight constraint on the inclination of the binary system. Title: EUV Spectroscopy of Solar and Stellar Atmospheres Authors: Young, P. R. Bibcode: 1998PhDT........50Y Altcode: A variety of extreme ultraviolet (EUV) spectra from satellite and rocket-borne instruments are studied and used both as a check on the quality of theoretical atomic data and to determine physical parameters for the solar atmosphere. In addition, atomic data for several ions found in the solar atmosphere are assessed for incorporation into the CHIANTI atomic database. For some of these ions it was necessary to compute data using the SSTRUCT atomic code. Data from the Skylab S082A instrument together with lines observed in the visible portion of the solar spectrum at an eclipse are used to derive estimates of the Ar/Ca relative abundance in the solar corona. A spectrum obtained by the Solar Extreme ultraviolet Rocket Telescope and Spectrograph (SERTS) is analysed thoroughly in order to check the accuracy of atomic data in the CHIANTI atomic database, and to derive electron densities for the observed region. Several data-sets obtained with the Coronal Diagnostic Spectrometer (CDS) onboard the Solar and Heliospheric Observatory (SOHO) are studied. The relative calibration of the two bandpasses of the Normal Incidence Spectrometer of CDS is investigated by comparing silicon and iron emission lines in different sets of spectra. Large variations in the Mg/Ne relative abundance are found within a single active region, and electron densities are derived. The spectra of an intense polar plume observed by CDS are analysed and physical parameters derived. Comparisons are made with the parameters for the coronal hole background. EUV spectra from the stars Alpha Centauri and Procyon obtained by the Extreme Ultra-Violet Explorer (EUVE) are presented. The physical parameters of these two solar-like stars are then compared. Title: Atomic Physics for Atmospheric Composition Measurements Authors: Young, P. R.; Mason, H. E. Bibcode: 1998SSRv...85..315Y Altcode: The atomic physics relevant to the interpretation of solar spectra produced by plasmas at temperatures ≳ 105 K are discussed. Methods for determining relative abundance ratios are presented and examples provided from the Coronal Diagnostic Spectrometer on board SOHO. In particular, the Fe/Si ratio in the corona is found to be close to photospheric; the Mg/Ne ratio in the transition region is found to vary by an order of magnitude in different solar features. The Mg/Ne ratios in supergranule cell centres and the network are separated for the first time, although no significant differences are found. Title: Atomic Data and Spectral Line Intensities for Mg VI Authors: Bhatia, A. K.; Young, P. R. Bibcode: 1998ADNDT..68..219B Altcode: Electron collision strengths for Mg VI, calculated in the distorted-wave approximation, are presented for all transitions between the 23 levels of the 2s22p3, 2s2p4, 2p5, and 2s22p23sconfigurations. Radiative data have been calculated utilizing the same four-configuration model of the ion. Proton rates for the transitions between the ground states are also presented. The level balance equations for Mg VI have been solved using these data and comparisons are made with previous results-excellent agreement is found. Theoretical line intensities for the important transitions are presented and compared with lines found in the extreme ultraviolet in a spectrum from the 1989 flight of the Solar EUV Rocket Telescope and Spectrograph. Recent data from the Coronal Diagnostic Spectrometer onboard the Solar and Heliospheric Observatory are also presented. Title: Giant, Repeating, Optical Bursts from the SXT Aqi X-1 Authors: Robinson, E. L.; Young, P.; Sanwal, D. Bibcode: 1998ASPC..137..547R Altcode: 1998wsow.conf..547R No abstract at ADS Title: CHIANTI: an atomic database for emission lines. II. Comparison with the SERTS-89 active region spectrum Authors: Young, P. R.; Landi, E.; Thomas, R. J. Bibcode: 1998A&A...329..291Y Altcode: The CHIANTI database was described by Dere et al. (1997, hereafter Paper I) and the present paper applies the atomic data to the study of extreme ultra-violet emission lines found in the SERTS-89 active region spectrum published by Thomas & Neupert (1994). Firstly, the emission line ratios that are insensitive to density and temperature are used to check both the quality of the atomic data and the calibration of the instrument. Secondly, we use, where possible, ratios that are sensitive to density to estimate the electron density from different ions. In general we find excellent agreement between theory and observation, providing confidence in both the atomic data in the CHIANTI database and the quality of the SERTS-89 spectrum. Where inconsistencies between theory and observation exist we try to explain them in terms of either inaccuracies in the atomic data or blending of the lines. One consistent discrepancy was that all observed lines that we analysed in the lambr{430}{450} region were uniformly a factor of 1.5--2.0 weaker than predicted, suggesting that the SERTS-89 calibration may need adjustment in this spectral interval. Serious problems were also found in some of the theoretical predictions for a few ions, especially ion{Fe}{xiv}. Title: Atomic Physics for Atmospheric Composition Measurements Authors: Young, P. R.; Mason, H. E. Bibcode: 1998sce..conf..315Y Altcode: No abstract at ADS Title: Surges and filaments in active regions during SOHO campaigns Authors: Schmieder, B.; Deng, Y.; Rudawy, P.; Nitta, N.; Mandrini, C. H.; Fletcher, L.; Martens, P.; Innes, D.; Young, P.; Mason, H. Bibcode: 1998ESASP.421..323S Altcode: 1998sjcp.conf..323S No abstract at ADS Title: CHIANTI - an Atomic Database For Emission Lines Paper I: Wavelengths Greater than 50 Angstroms Authors: Dere, K. P.; Landi, E.; Mason, H. E.; Fossi, B. C. M.; Young, P. R. Bibcode: 1998ASPC..143..390D Altcode: 1998sigh.conf..390D No abstract at ADS Title: EUV spectroscopy of solar and stellar atmospheres Authors: Young, Peter Rousselange Bibcode: 1998PhDT........94Y Altcode: No abstract at ADS Title: Active Regions Observed in Extreme Ultraviolet Light by the Coronal Diagnostic Spectrometer on SOHO Authors: Fludra, A.; Brekke, P.; Harrison, R. A.; Mason, H. E.; Pike, C. D.; Thompson, W. T.; Young, P. R. Bibcode: 1997SoPh..175..487F Altcode: We present observations of five active regions made by the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory (SOHO). CDS observes the Sun in the extreme ultraviolet range 150-780 Å. Examples of active region loops seen in spectral lines emitted at various temperatures are shown. Several classes of loops are identified: those that are seen in all temperatures up to 2 x 106 K; loops seen at 106 K but not reaching 1.6 x 106 K; those at temperatures 2- 4 x 10-5 K and occasionally at 6 x 10-5 K but not reaching 106 K. An increasing loop size with temperature and the relationship between the cool and hot structures is discussed. CDS observations reveal the existence of loops and other unresolved structures in active regions, at temperatures between 1.5- 4 x 10-5 K, which do not have counterparts in lines emitted above 8 x 10-5 K. Bright compact sources only seen in the transition region lines are investigated. These sources can have lifetimes of up to several days and are located in the vicinity of sunspots. We study the variability of active region sources on time scales from 30 sec to several days. We find oscillatory behaviour of Hei and Ov line intensities in an active region on time scales of 5-10 min. Title: CHIANTI - an atomic database for emission lines Authors: Dere, K. P.; Landi, E.; Mason, H. E.; Monsignori Fossi, B. C.; Young, P. R. Bibcode: 1997A&AS..125..149D Altcode: A comprehensive set of accurate atomic data is required for analyses of astrophysical and solar spectra. CHIANTI provides a database of atomic energy levels, wavelengths, radiative data and electron excitation data for ions which are abundant in cosmic plasmas. The most recent electron excitation data have been assessed and stored following the method of \cite[Burgess \& Tully (1992)]{bur92}. The current version is essentially complete for specifying the emission spectrum at wavelengths greater than 50 Angstroms. A list of observed lines in the spectral region between 50 and 1100 Angstroms has been compiled and compared with the lines predicted by the CHIANTI database. The CHIANTI database reproduces the vast majority of lines observed at these wavelengths. CHIANTI includes IDL (Interactive Data Language) routines to calculate optically thin synthetic spectra for equilibrium conditions. IDL routines to calculate theoretical line intensities required for electron density or temperature diagnostics and emission measure studies are also included. The CHIANTI atomic database and supporting IDL routines are available by anonymous FTP. Title: The Mg/Ne abundance ratio in a recently emerged flux region observed by CDS Authors: Young, P. R.; Mason, H. E. Bibcode: 1997SoPh..175..523Y Altcode: Evidence for the existence of the FIP-effect in the transition region is presented here based on recent observations from the Coronal Diagnostic Spectrometer (CDS) on-board the Solar and Heliospheric Observatory (SOHO). Observations of an emerging flux region in lines of Mgv-vii and Nevi-vii reveal differences in the relative Mg/Ne abundance of a factor of 9.2 between two transition region brightenings separated by less than 1 arc min on the Sun. The lower abundance ratio is approximately equal to the photospheric Mg/Ne value and is associated with a small loop-like feature in the central, hottest part of the active region. The higher abundance ratio is found in spike-like structures at the edge of the active region. A density diagnostic of Oiv is used to derive an electron number density of 1011.3 cm-3 for the low Mg/Ne brightening, while a Mgvii diagnostic gives a density of 109.2 cm for the high Mg/Ne brightening. Title: The Tully-Fisher relation in nearby clusters Authors: Young, P. Bibcode: 1997Obs...117..248Y Altcode: No abstract at ADS Title: The Ar/Ca relative abundance in solar coronal plasma. Authors: Young, P. R.; Mason, H. E.; Keenan, F. P.; Widing, K. G. Bibcode: 1997A&A...323..243Y Altcode: The relative abundances of elements with low and high first ionisation potentials (FIP) is a subject of much recent debate. In situ measurements of the solar wind reveal a clear pattern of low FIP enhancement that has been followed up with various spectroscopic measurements of the solar corona. Argon is unique amongst the more abundant high FIP elements in retaining several of its electrons at the high temperatures seen in flares. This allows emission lines of different ions to be compared with more confidence than for, say, hydrogen-like high FIP ions such as OVIII and NeX. In this paper we look at emission lines of the boron-like ion ArXIV; in particular, the optical line at 4412Å, seen in eclipse observations, is compared to the CaXIII 4086Å and CaXV 5445Å & 5694Å lines to yield an Ar/Ca abundance of 0.85+/- 0.20. In the extreme ultra-violet (EUV), the ArXIV lines at 187.94Å and 194.41Å can be compared with CaXIV 193.87 Å - flare data from Skylab giving values of 1.10+/-0.25 and 0.55+/-0.21. Analysis of previous work indicates a photospheric Ar/Ca abundance of 1.31+/-0.30, hence supporting the conclusion that elements with high FIP have lower coronal abundances. Title: VizieR Online Data Catalog: CHIANTI - An Atomic Database For Emission Lines I. (Dere+ 1997) Authors: Dere, K. P.; Landi, E.; Mason, H. E.; Monsignori Fossi, B. C.; Young, P. R. Bibcode: 1997yCat..41250149D Altcode: A comprehensive set of accurate atomic data is required for analyses of astrophysical and solar spectra. CHIANTI provides a database of atomic energy levels, wavelengths, radiative data and electron excitation data for ions which are abundant in cosmic plasmas. The most recent electron excitation data have been assessed and stored following the method of Burgess & Tully (1992A&A...254..436B). The current version is essentially complete for specifying the emission spectrum at wavelengths greater than 50Å. A list of observed lines in the spectral region between 50 and 1100Å has been compiled and compared with the lines predicted by the CHIANTI database. The CHIANTI database reproduces the vast majority of lines observed at these wavelengths. CHIANTI includes IDL (Interactive Data Language) routines to calculate optically thin synthetic spectra for equilibrium conditions. IDL routines to calculate theoretical line intensities required for electron density or temperature diagnostics and emission measure studies are also included. The CHIANTI atomic database and supporting IDL routines are available by anonymous FTP. (1 data file). Title: Application of Spectroscopic Diagnostics to Early Observations with the SOHO Coronal Diagnostic Spectrometer Authors: Mason, H. E.; Young, P. R.; Pike, C. D.; Harrison, R. A.; Fludra, A.; Bromage, B. J. I.; Del Zanna, G. Bibcode: 1997SoPh..170..143M Altcode: The Coronal Diagnostic Spectrometer (CDS) has as a scientific goal the determination of the physical parameters of the solar plasma using spectroscopic diagnostic techniques. Absolute intensities and intensity ratios of the EUV spectral emission lines can be used to obtain information on the electron density and temperature structure, element abundances, and dynamic nature of different features in the solar atmosphere. To ensure that these techniques are accurate it is necessary to interface solar analysis programs with the best available atomic data calculations. Progress is reported on this work in relation to CDS observations. Title: CHIANTI - an Atomic Database for Emission Line Spectroscopy: Version 1 - Wavelengths greater than 50 Angstroms Authors: Dere, K. P.; Monsignori-Fossi, B. C.; Landi, E.; Mason, H. E.; Young, P. R. Bibcode: 1996AAS...188.8501D Altcode: 1996BAAS...28..961D A comprehensive set of accurate atomic data is required for analyses of astrophysical and solar spectra. CHIANTI provides an atomic database of energy levels (wavelengths), radiative data and electron excitation data for ions which are abundant in astrophysical plasmas. The most recent electron excitation data have been assessed and stored following the method of Burgess and Tully (1992). CHIANTI includes IDL (Interactive Data Language) routines to produce optically thin synthetic spectra for lambda > 50 Angstroms, assuming equilibrium conditions. It also includes IDL routines to calculate theoretical line intensities required for electron density or temperature diagnostics and emission measure studies. The CHIANTI atomic database and supporting IDL routines are available by anonymous FTP. Title: EUV density diagnostics in solar and stellar spectra Authors: Young, P. R.; Mason, H. E. Bibcode: 1996ASPC..109..301Y Altcode: 1996csss....9..301Y No abstract at ADS Title: EUV Line Intensities of Fe X Authors: Young, P. R.; Mason, H. E.; Bhatia, A. K.; Doschek, G. A.; Thomas, R. J. Bibcode: 1996aeu..conf..583Y Altcode: 1996IAUCo.152..583Y No abstract at ADS Title: EUV and infra-red lines of FE XIII Authors: Young, P. R.; Mason, H. E.; Thomas, R. J. Bibcode: 1994ESASP.373..417Y Altcode: 1994soho....3..417Y No abstract at ADS Title: The Effect of Low Earth Orbit Exposure on Some Experimental Fluorine and Silicon-Containing Polymers Authors: Connell, J. W.; Young, P. R.; Kalil, C. G.; Chang, A. C.; Stochi, E. J. Bibcode: 1994NASCP3280..157C Altcode: No abstract at ADS Title: Improved galaxy cluster distances from an optical Tully-Fisher relation Authors: Young, P.; Sharples, R.; Lucey, J.; Staveley-Smith, L. Bibcode: 1993cvf..conf..601Y Altcode: No abstract at ADS Title: Pulsar mystery ends : the TV camera did it. Authors: Young, P. Bibcode: 1990SciN..137..119Y Altcode: No abstract at ADS Title: Why Isn't "My Discovery" News? Authors: Young, P. Bibcode: 1989BAAS...21.1185Y Altcode: No abstract at ADS Title: Spectroscopy of the Magnetic Binary Remnant of Nova V1500 Cygni 1975 Authors: Horne, K.; Schneider, D. P.; Young, P. Bibcode: 1987BAAS...19.1057H Altcode: No abstract at ADS Title: High-Resolution Spectra of 24 Low-Redshift QSOs: The Properties of MG II Absorption Systems Authors: Tytler, David; Boksenberg, A.; Sargent, Wallace L. W.; Young, Peter; Kunth, Daniel Bibcode: 1987ApJS...64..667T Altcode: High-resolution spectra of 245 low-redshift QSOs are presented, and Mg II emission-line equivalent widths and velocity widths are measured and briefly discussed. Improved statistical methods are presented for the extraction of significant absorption features from spectra. These techniques provide a simple and accurate estimate of the minimum equivalent widths which could be detected in any region of a spectrum. A search for Galactic Ca II in 13 lines of sight reveals five detections. Equivalent widths are in the range 0.2-0.3 A. Only three redshifted absorption systems were found, all dominated by Mg II 2796 A, 2803 A doublets. Mg(+)/Mg(0) and Mg(+)/Fe(+) values cannot be accounted for by collisional ionization alone. Factors determining the frequency of occurrence of Mg II systems are investigated using a composite sample of 14 systems from the spectra of 90 QSOs. Ten out of the 14 systems occur in five pairs of two systems each per QSO. The probability of these pairs being chance occurrences is only 0.0007. Title: Intergalactic Lyman-alpha absorption lines in a close pair of high-redshift QSOs. Authors: Sargent, W. L. W.; Young, P.; Schneider, D. P. Bibcode: 1982ApJ...256..374S Altcode: Spectra of Q1623+269 and Q1623+268 were obtained and these objects were confirmed as QSO's with redshifts about 2.5. The separation of only 2.9 arcmins corresponds at redshift 2.5 to a projected linear separation on the plane of sky of only 1-2 Mpc. It is shown in detail that the corresponding differential Hubble velocity over 1-2 Mpc at redshift 2.5 is about 400 km/s. Thus, a study of the redshift distribution of the Lyman alpha absorption lines in these two objects is capable of giving information on the clustering of the Lyman alpha clouds on linear scales of 1-2 Mpc or velocity scales of about 400 km/s. Lists are derived of observed absorption lines for each QSO, and the distribution of Lyman alpha lines is considered. It is shown how cross-correlation and autocorrelation analyses of the Lyman alpha absorption line positions may be used to study the clustering of the clouds responsible for the lines. Title: C IV absorption in an unbiased sample of 33 QSOs: evidence for the intervening galaxy hypothesis. Authors: Young, P.; Sargent, W. L. W.; Boksenberg, A. Bibcode: 1982ApJS...48..455Y Altcode: Observations of 27 QSOs at redshifts of z(em) approximately equals 2 with 2.5 A resolution are presented, and a homogeneous sample of 33 QSOs is prepared to examine statistical properties of C IV 1548, 1550 A absorption systems. Three QSOs out of 33 have broad absorption troughs of material ejected by the QSO at velocities up to 0.1 c, while in the other thirty QSOs, the C IV doublets are uniformly distributed in the spectra in a manner consistent with predictions for clouds randomly distributed along the line of sight in a Friedmann universe. No evidence is found for an excess of absorption line systems in the nontroughed QSOs near the emission redshift, and in Q1309-056 there exists strong statistical evidence that the systems are ejected from the QSO. It is suggested that most of the metal line absorption systems in QSOs without broad troughs arise from the halos of intervening galaxies and other objects unconnected with the QSOs. Title: A high-resolution study of the absorption spectra of three QSOs: evidence for cosmological evolution in the Lyman-alpha lines. Authors: Young, P.; Sargent, W. L. W.; Boksenberg, A. Bibcode: 1982ApJ...252...10Y Altcode: High-resolution (0.8 Å FWHM) spectroscopic observations over the wavelength range from 3260 Å to 4900 Å are presented for the QSOs Q0002+051 (Zem = 1.899), Q0421+019 (Zem = 2.051), and the gravitationally lensed QSO, Q1115+080 (Zem = 1.725). We find, respectively, 28, 53, and 21 absorption lines in these three objects, from which a total of 11 absorption line systems are identified. Two of the QSOs show galactic Ca II λλ3934, 3969 absorption. Four absorption systems with Zabs > Zem are seen in Q1115+080; the velocities range from -360 to -1130 km s-1 relative to the QSO. Line profile fits to the absorption spectra are used to determine column densities and velocity dispersions within the absorbing clouds. Highly ionized lines of C IV λλ1548, 1550, N V λλ1238, 1242, and Si IV λλ1393, 1402 are seen in many of the absorption systems.

The many unidentified lines shortward of Ly emission are used to form an expanded sample of single Lyα absorption lines. The new data provide good statistics for Zabs < 2 and reveal a number density per unit redshift N(Z) = N0(1 + Z)γ with y = 1.81 ± 0.48. This suggests a modest amount of cosmological evolution in the sense that there are more Lyα absorption lines at higher redshifts. The properties of the equivalent width spectrum of Lyα lines and the flatness of their two-point correlation function are in accord with our previous study. Title: A high-resolution spectroscopic study of Q0119-046 and the nature of absorption complexes with z(abs) > z(em). Authors: Sargent, W. L. W.; Young, P.; Boksenberg, A. Bibcode: 1982ApJ...252...54S Altcode: In addition to finding 61 absorption lines in the QSO Q0119 through high-resolution spectroscopic observations over the wavelength range from 3260 to 4920 A, seven main absorption line redshifts ranging from 0.6577 to 1.9751 are determined. A complex of three main systems whose absolute redshift is greater than the emission redshift is found, with infall velocities relative to the QSO ranging from -2780 to 3870 km/sec. The strongest absorption system of the complex shows C II 1334 A and excited fine structure C II 1335 A lines, implying a gas density greater than 100/cu cm. The best of the possible explanations for such complexes is that they arise from a cluster of galaxies, which is perhaps collapsing, and of which the QSO is a member. The high-velocity filaments in NGC 1275 may be similar to the clouds responsible for the redshift systems discussed. Title: 2A 0311-227 (EF Eri) : radial velocities of two emission line components. Authors: Young, P.; Schneider, D. P.; Sargent, W. L. W.; Boksenberg, A. Bibcode: 1982ApJ...252..269Y Altcode: The magnetic binary 2A 0311-227 is observed for more than three orbits on each of two nights with 1 A spectral resolution and 120 s temporal resolution. The radial velocity variations of the strong Balmer, He I, and He II emission lines in the region 4110-5050 A are investigated. It is noted that the emission lines are distinctly from cycle to cycle. For approximately 50% of the time, the lines consist of a single broad component (sometimes with hints of substructure) phased with the 81 minute orbital period. At other times, a second 'sharp' emission component appears in all lines, most notably in He II 4686 A. The sharp component possesses an 81 minute radial velocity period, with K equal to 600 km/s. It lags the broad component in phase by 55 deg. Other components are seen transiently but do not reproduce from cycle to cycle, including a high velocity component observed at +1200 km/s. It is noted that the multiple emission components cannot be due to magnetic effects and that the sharp component has too large a velocity to represent orbital motion. Title: The origin of a new absorption system discovered in both components of the double QSO Q0957+561. Authors: Young, P.; Sargent, W. L. W.; Boksenberg, A.; Oke, J. B. Bibcode: 1981ApJ...249..415Y Altcode: A new absorption-line system at z(abs) of 1.1249 has been discovered by UV spectroscopy, at 1.2 A resolution, of the two gravitationally lensed images of Q0957+561. The line system is visible as a C IV 1548-1550 A doublet in both images of Q0957+561A,B, with absorption lines having the same strengths in both images and a velocity difference of -8 + or - 11 km/sec. The absorbing cloud velocity dispersion is less than 26 km/sec. Two interpretations are given of the observed z(em)-z(abs) value: (1) that of an ejection, in which it corresponds to a velocity of 37,500 km/sec, and (2) that of the result of an intervening galaxy or intergalactic cloud, according to which it would lie at a distance of about 300 Mpc from the QSO. It is shown that the small velocity difference observed in the absorption lines in the two images strengthens the ejection hypothesis for this system. It is suggested that the discovery of multiple structure in the z(abs) 1.1249-value system will strengthen the evidence for ejection. Title: A quest for the red companion in six cataclysmic binaries. Authors: Young, P.; Schneider, D. P. Bibcode: 1981ApJ...247..960Y Altcode: Near-infrared CCD spectra of six cataclysmic binaries have been obtained in an attempt to detect their red dwarf components. Similar observations of M dwarfs yield a classification scheme, based on TiO bands, which can be used to describe the red dwarfs in cataclysmic binaries. Observations of AM Her while in its low state revealed a red dwarf of type M4(+) V and a distance of 80 pc. The red dwarf in DQ Her was detected in an observation centered on mid-eclipse. The red star in DQ Her has a spectral type of M3(+) V, a mass = 0.32 solar mass, and a radius = 0.45 solar radius. The red star in DQ Her does not lie on the main sequence; although its temperature is correct for its mass, the radius is 25% too large. A spectroscopic distance estimate of 400 pc to the DQ Her binary system was obtained; in four additional systems, the red dwarf defied detection. Lower limits to their distances are given. Title: AM Herculis : the magnetic maw uncloaks itself. Authors: Young, P.; Schneider, D. P.; Shectman, S. A. Bibcode: 1981ApJ...245.1043Y Altcode: We have obtained a complete orbit of spectroscopy at 2.3 Å resolution on AM Herculis in its low state. We find:

1. Strong, sharp Hβ, Hγ, and Hδ lines and weak, sharp He I λλ4471, 4922, and 5015 lines. The He II 4686 line is also weak and sharp. There is no trace of the broad emission component present at high state. The radial velocity amplitude K = 79 km s-1 and fiducial phase φ0 = 0.61 identify the sharp emission as being related to the sharp emission component seen at high state.

2. The spectrum is stuffed with broad absorption troughs flanking the Balmer lines. These troughs are 10% deep, 80 Å wide, and vary in strength with orbital phase (being strongest at φmag = 0.6). The troughs show internal structure and are identified as being Zeeman-shifted multiplets of Hβ, Hγ, and Hδ seen in a magnetic field of 1.3 × 107 gauss. The trough structure allows us to place a limit of 106 gauss in the variation of the magnetic field in the absorption region. This suggests the lines arise from the accreting polar cap of the white dwarf.

3. Lower resolution (13 A) spectra in the red show strong, narrow Hα emission. The energy distribution rises sharply longward of 6500 Å, and there are broad, deep TiO bands from the M4.5 V red dwarf in the binary system. The Zeeman components of Hα are confused with some of these TiO bands. Title: The voracious vortex in HT Cassiopeiae. Authors: Young, P.; Schneider, D. P.; Shectman, S. A. Bibcode: 1981ApJ...245.1035Y Altcode: The sixteenth magnitude cataclysmic binary HT Cassiopeiae has been observed at 2.3 Å spectral resolution and 75 s time resolution in the region 3980-5050. Three orbits and three eclipses of this 1h46m binary have been covered. We find: (i) strong Balmer and He I emission. The lines are double peaked, 2800 km s-1 wide, and the central absorption dip reaches down to the continuum in He I. The K velocity of the Balmer lines is 115 km s-1. The velocity phase is offset from the eclipse by 30° and cannot be explained by the &wave effect. (ii) Eclipses of the emission lines show that mW = 0.53Msun, mR = 0.19 Msun(q = 2.8), and α = 0.66 Rsun. The brevity of the eclipse indicates i = 76°. (iii) The strong wings on the emission lines require a disk line emissivity that increases toward small radii as r-3/2. Title: MV LYR : a spectroscopic study of the low state. Authors: Schneider, D. P.; Young, P.; Shectman, S. A. Bibcode: 1981ApJ...245..644S Altcode: MV Lyrae is found to have a period of 0.1336 days from radial velocity variations. While in the low state the spectrum exhibits sharp, strong Balmer emission and sharp, weak He I emission. The radial velocity amplitude of the Balmer lines is 44 km/s; the He I lines have a lower amplitude of 16 km/s. Broad, shallow Balmer absorption and He II 4686 A absorption are also seen. Infrared observations show TiO bands and the Na I 8183-8194 A lines; these features arise from an M5V red dwarf in the system. The infrared spectrum combined with four-color photometry yields a distance estimate of 320 pc to MV Lyr. Title: Q0957+561 : effects of random stars on the gravitational lens. Authors: Young, P. Bibcode: 1981ApJ...244..756Y Altcode: Computer simulations were used to study the effect of the discrete stellar nature of the gravitational lens galaxy on the imaging of Q0957+561. The source size of Q0957+561 is probably about 6 x 10 to the 16th cm in the optical continuum. It is predicted that all three images will vary by 50% on a time scale of 100 years due to perturbations by stars in the galaxy. The effect of very low mass stars in the galaxy halo and cluster is virtually undetectable for the postulated source size of Q0957+561 in the B1 and B2 faint images. Finally, it is found that the observed 30% variations in the flux of Q0957+561 are unlikely to be due to perturbations by stars. Title: The triple quasar Q1115+080A, B, C : a quintuple gravitational lens image. Authors: Young, P.; Deverill, R. S.; Gunn, J. E.; Westphal, J. A.; Kristian, J. Bibcode: 1981ApJ...244..723Y Altcode: Spectroscopy and direct imaging of Q1115+080A, B, C with a CCD camera support the hypothesis that they are gravitational images of a single object. Spectroscopy of the semiforbidden C III 1909-A emission line shows all the images to have identical spectra and redshifts (to within 100 km/s), except that B is slightly redder. Gravitational lens imaging by a massive spiral galaxy is investigated, and a quintuple image model resembling Q1115+080A, B, C is found. In this model, Q1115+080A is a highly magnified close pair of images oriented in the position angle 23 deg. An elongation Q1115+080A at this angle is seen in the CCD pictures. Title: Q0957+561 : detrailed models of the gravitational lens effect. Authors: Young, P.; Gunn, J. E.; Kristian, J.; Oke, J. B.; Westphall, J. A. Bibcode: 1981ApJ...244..736Y Altcode: The galaxy responsible for causing multiple gravitational lens images of QSO Q0957+561 has been reobserved spectroscopically and a more accurate redshift of 0.36 was obtained. In addition, detailed models of the gravitational lens effect were computed. These models, which can explain all optical and radio data for the system, predict delays of up to five years between variations in the A and B images (with A preceding B). It is suggested that the third image is rather faint and located close to the center of the lens galaxy; it is possible that this third image contributes to the observed galaxy core. The possibility that this system can be used to measure the Hubble constant is discussed. Title: A radial velocity study of emission in Stepanyan's star. Authors: Young, P.; Schneider, D. P.; Shectman, S. A. Bibcode: 1981ApJ...244..259Y Altcode: Emission lines in the region 4045-4945 A are observed for nearly two complete orbits of Stepanyan's star. Three eclipses of the system are observed at 2.5 A spectral and 100 second time resolution. The spectral region 6800-9200 A is observed for one complete orbit at 10 A resolution. No absorption lines or bands from a red dwarf are observed, even at mid-eclipse. Absorption lines of O I are seen in the infrared, which are strongest at phases 0.4-0.5 and are invisible at mid-eclipse. Title: Design of Infrared Astronomical Satellite (IRAS) primary mirror mounts. Authors: Schreibman, M.; Young, P. Bibcode: 1981OptEn..20..190S Altcode: Abstract. The design of an operational mount to rigidly secure the primary mirror to its baseplate without the introduction of figure error always proves to be a major task on diffraction limited optical systems. A summary of the design of the Infrared Astronomical Satellite (RAS) primary mirror mount is given. The mirror was designed to be aligned and tested at room temperature and operated in a zero "g"field at temperatures of 2 Kbo minimize overstressing, a stiffness requirement of greater than 150 Hz was required for cold launch and room temperature vibration acceptance testing. Additional isolation was required to minimize strains, introduced via the mounting base, due to thermal and mechanical distortions. Title: Numerical models of star clusters with a central black hole. I - Adiabatic models. Authors: Young, P. Bibcode: 1980ApJ...242.1232Y Altcode: Numerical models of star clusters containing a massive black hole are computed for the case of a black hole which grows adiabatically in the cluster center. The growth of the hole is assumed to be at a rate longer than the cluster dynamical time scale but shorter than the relaxation time scale. The angular momentum and radial action of each star in the cluster are conserved during the adiabatic variations. This leads to the invariance of the distribution function in (E, J) space which is used to facilitate the numerical calculations. A power-law density cusp forms near the black hole. When the hole has grown to exceed the core mass of the cluster, this cusp joins smoothly onto the isothermal density law. Title: The double quasar Q0957+561 A, B: a gravitational lens image formed by a galaxy at z=0.39. Authors: Young, P.; Gunn, J. E.; Kristian, J.; Oke, J. B.; Westphal, J. A. Bibcode: 1980ApJ...241..507Y Altcode: Deep CCD pictures show a rich cluster of galaxies around the double quasar Q0957 + 561 as well as faint extended wings on the image of the southern quasar. Calculations of gravitational imaging by King model mass distributions show that the cluster and the brightest galaxy together, acting as a gravitational lens on the light from a single, more distant QSO, can easily reproduce all of the present observations. It is concluded that the double quasar is almost certainly the multiple image of a single object produced by a gravitational lens. Title: VV Puppis and AN Ursae Majoris: a radial velocity study. Authors: Schneider, D. P.; Young, P. Bibcode: 1980ApJ...240..871S Altcode: The observations of the emission lines of VV Puppis and AN Ursae Majoris show spectacular line variations in VV Puppis with a mean radial velocity amplitude of 376 km/s and clearly defined broad and sharp components. The AN UMa has similar, but less spectacular variations; the mean radial velocity of 256 km/s and the base and emission lines are 49 deg out of phase. Integration of particle trajectories in the Roche geometry where a dipole magnetic field dominates the gas flow confirms that gas is threaded on the magnetic field near the L(1) point from which it free-falls onto the favorably oriented magnetic pole of the white dwarf. Title: Emission line eclipse phenomena in nova DQ HER (1934). Authors: Young, P.; Schneider, D. P. Bibcode: 1980ApJ...238..955Y Altcode: H-gamma, He II 4686 A, and H-beta emission lines were observed in DQ Her through an eclipse (phases 0.80-0.15). A total of 14 spectra with exposure times of 300 seconds were used to investigate phenomena in the eclispe of the emitting region by the red companion. The classical rotational disturbance of the He II 4686 A line is observed; it changes its velocity by over 600 km/s in 25 minutes during the eclipse. The eclipse duration is very long (0.11 of a cycle) and indicates a mass ratio near unity. Title: The magnetic maw of 2A 0311-22.7. Authors: Schneider, D. P.; Young, P. Bibcode: 1980ApJ...238..946S Altcode: A radial velocity study of the AM Herculis-type X-ray binary 2A 0311-227 was performed. Phase-dependent changes in profile were observed; the line bases have K = 430 km/s and the peaks have K = 240 km/s. The peaks have a phase lag of 25 deg relative to the bases, and the Balmer lines exhibit drastic changes in strength through the cycle in the sense that they are weak for large velocity displacements of the lines. It is suggested that the emission lines may arise from material in a magnetic funnel dropping onto the magnetic pole of a white dwarf. Title: Design of infrared astronomical satellite (IRAS) primary mirror mounts. Authors: Schreibman, M.; Young, P. Bibcode: 1980SPIE..250...50S Altcode: The design of an operational mount to rigidly secure the primary mirror to its baseplate without the introduction of figure error always proves to be a major task on diffraction limited optical systems. A summary of the design of the Infrared Astronomical Satellite (IRAS) primary mirror mount is given. The mirror was designed to be aligned and tested at room temperature and operated in a zero "g" field at temperatures of 2K. To minimize overstressing, a stiffness requirement of greater than 150 Hz was required for cold launch and room temperature vibration acceptance testing. Additional isolation was required to minimize strains, intro-duced via the mounting base, due to thermal and mechanical distortions. Title: 00957+561A 00957+561B - a Gravitational Lens Image Formed by a Galaxy at z= 0.4 Authors: Young, P.; Gunn, J.; Kristian, J.; Oke, J.; Westphal, J. Bibcode: 1980BAAS...12..438Y Altcode: No abstract at ADS Title: Gravity's Lens - Squinting at a Galaxy Authors: Walsh, D.; Carswell, R. F.; Weymann, R. J.; Burke, B. F.; Greenfield, P. E.; Roberts, D. H.; Becklin, E. E.; Young, P.; Gunn, J. E.; Kristian, J.; Oke, J. B.; Westphal, J. A. Bibcode: 1980SciN..117...36W Altcode: No abstract at ADS Title: Alignment design for a cryogenic telescope. Authors: Young, P.; Schreibman, M. Bibcode: 1980SPIE..251..171Y Altcode: This paper describes the alignment approach for the infrared astronomical satellite (IRAS) optical subsystem from initial design to acceptance testing. The constraints imposed by the requirement of maintaining alignment at 300K and 2K, in a 1-g and 0-g gravitational field, during warm and cold vibration, and during various stages of assembly, are discussed. The paper concludes with the methodology of applying NASTRAN finite element analyses to the alignment design, followed by the verification of the accuracy of the design with the test results. Title: Improved infrared observations of AM Herculis. Authors: Young, P.; Schneider, D. P. Bibcode: 1979ApJ...230..502Y Altcode: Sharp emission lines of He I and Ca II, a broad emission line of He I, and absorption lines of Na I have been studied in Coude spectroscopy of AM Herculis, the prototype of a new class of X-ray binaries. The absorption system suggests a mass function of 0.071 plus or minus 0.017 solar masses. The red dwarf appears to lie between types M4V and M5V; according to a Roche lobe analysis, the star obeys a normal mass-radius relationship for a lower main-sequence object. The mass of the white dwarf cannot be determined precisely. UV irradiation of the hemisphere of the red star which faces the white dwarf may account for the sharp emission lines. Collisional excitation around the white dwarf may be associated with the broad-line emission system. Title: Periodic Comet Kowal 2 (1979a) Authors: Young, P.; Kowal, C.; Shao, C. -Y.; Bulger, J. H.; Marsden, B. G. Bibcode: 1979IAUC.3346....2Y Altcode: Further precise positions have been reported as follows: 1979 UT R. A. (1950) Decl. m1 Observer Mar. 1.17118 4 24 56.45 + 9 28 47.1 17 Young 23.23264 5 23 54.43 + 9 45 04.2 18 Kowal 28.08417 5 36 43.12 + 9 45 09.3 Shao P. Young and C. Kowal (Hale Observatories). Measurer: Kowal. Extremely weak and diffuse on Mar. 23. C.-Y. Shao (Harvard College Observatory, Agassiz Station). 155-cm reflector. Measurer: J. H. Bulger. Improved orbital elements, by the undersigned, from 11 observations Jan. 27 to Mar. 28: T = 1979 Jan. 13.740 ET Peri. = 189.380 e = 0.56380 Node = 247.163 1950.0 a = 3.48667 AU Incl. = 15.807 n = 0.151387 q = 1.52090 AU P = 6.51 years 1979 ET R. A. (1950) Decl. Delta r m1 May 7 7 17.68 + 8 25.3 2.091 1.901 18.9 17 7 41.32 + 7 41.3 27 8 04.21 + 6 48.3 2.362 2.017 19.4 June 6 8 26.35 + 5 47.1 16 8 47.73 + 4 38.6 2.638 2.139 19.9 26 9 08.39 + 3 23.8 July 6 9 28.35 + 2 03.5 2.909 2.263 20.4 Title: The Radio Galaxies NGC6251 and M87 - M87 Jet - Seyfert Galaxies Authors: Sargent, W. L. W.; de Bruyn, A.; Readhead, A. C. S.; Young, P.; Kristian, J.; Westphal, J.; Boksenberg, A.; Bertola, F.; Holm, A.; Arp, H. C.; Arnold, S. J.; Sulentic, J.; Daltabuit, E.; Matthews, K.; Morton, D. C.; Neugebauer, G.; Oke, J. B.; Persson, E.; Smith, A. M.; Soifer, B. T.; Zimmerman, B. Bibcode: 1979haob.rept..754S Altcode: No abstract at ADS Title: Dynamics of the flattened elliptical galaxy NGC 4473. Authors: Young, P.; Sargent, W. L. W.; Boksenberg, A.; Lynds, C. R.; Hartwick, F. D. A. Bibcode: 1978ApJ...222..450Y Altcode: Spectroscopic observations of the E5 galaxy NGC 4473 to a distance of 45 sec (3300 pc) from the center along the major axis are used to make the first estimates of the radial variation of rotation and velocity dispersion in a galaxy away from the regions of the core. Analysis with Fourier techniques shows the rotation curve to have an observed semiamplitude of 60 km/s (or 86 km/s when corrected for projection). The velocity dispersion 180 km/s is constant along the major axis of the galaxy to a distance of 45 sec, and the line strengths fall by 35%. The kinetic energy ratio Trot/T sub ran = 0.08 demonstrates that the galaxy is pressure supported. The mass interior to 3.3 kpc radius is determined to be 46 billion solar masses. The mass to light ratio of the system is M/L = 6, and increases slowly with radius. Title: Comet Kohier (1977m) Authors: McCutcheon, R. A.; Young, P.; Bus, S. J.; Jones, A. F.; Marsden, B. G. Bibcode: 1978IAUC.3205....2M Altcode: Further precise positions have been reported as follows: 1977/78 UT R. A. (1950) Decl. Observer Oct. 7.02847 16 42 52.05 +16 27 25.4 McCutcheon Jan. 8.13675 0 20 21.66 -34 02 10.4 Young R. A. McCutcheon (Yale University Observatory, Bethany Station). P. Young (Palomar Mountain Observatory). Measurer: S. J. Bus. The following elliptical elements, by the undersigned, are based on 270 observations 1977 Sept. 6 to 1978 Jan. 30, perturbations by all nine planets being taken into account: Epoch = 1977 Oct. 24.0 ET T = 1977 Nov. 10 5701 ET Peri. = 163.4880 e = 0.999502 Node = 181.8240 1950.0 q = 0.990570 AU Incl. = 48.7181 1978 ET R. A. (1950) Decl. Delta r m2 June 1 5 57.95 -14 28.4 3.780 3.101 17.8 11 6 13.23 -14 20.9 21 6 27.83 -14 24.7 4.059 3.327 18.3 July 1 6 41.75 -14 39.0 11 6 54.97 -15 03.3 4.298 3.548 18.7 21 7 07.45 -15 37.0 31 7 19.17 -16 19.4 4.488 3.765 19.0 Aug. 10 7 30.09 -17 09.7 20 7 40.15 -18 07.4 4.626 3.978 19.3 30 7 49.30 -19 11.6 Sept. 9 7 57.46 -20 21.5 4.711 4.188 19.6 19 8 04.54 -21 36.0 29 8 10.47 -22 54.1 4.747 4.394 19.8 Oct. 9 8 15.14 -24 14.5 19 8 18.44 -25 35.5 4.744 4.596 20.0 29 8 20.29 -26 55.2 Nov. 8 8 20.60 -28 11.4 4.718 4.795 20.2 18 8 19.33 -29 21.3 28 8 16.50 -30 22.2 4.693 4.992 20.3 Dec. 8 8 12.21 -31 11.0 18 8 06.65 -31 44.8 4.697 5.185 20.5 m2 = 10.0 + 5 log Delta + 10 log r Total visual magnitude estimates by A. F. Jones, Nelson, New Zealand (31-cm reflector): Feb. 6.39 UT, 12.4; 8.37, 12.4. Title: 1977 VA Authors: Helin, E.; Young, P. Bibcode: 1978IAUC.3158....3H Altcode: The following precise positions have been measured by E. Helin from exposures by P. Young with the 46-cm Schmidt at Palomar: 1977 UT R. A. (1950) Decl. Nov. 16.26319 2 48 15.12 +13 02 40.8 17.35208 2 51 25.52 +12 55 14.6 Title: Drifting continents, shifting seas. Authors: Young, P. Bibcode: 1976dcss.book.....Y Altcode: No abstract at ADS Title: Nova Cygni 1975 Authors: Fawley, W. M.; de Vaucouleurs, G.; Bryan, J.; Young, P.; Burkhead, M. S.; Krempec, J.; Ney, E. P.; Hatfield, B.; Nissen, W.; Jacchia, L.; di Cicco, D.; Sherrod, C.; Maley, P.; Hull, A. B.; Woszczyk, A.; Burnicki, A.; Iwanowska, W.; Krawczyk, S.; Strobel, A.; Hutchings, J. B.; Mannery, E.; Schommer, R. Bibcode: 1975IAUC.2832....1F Altcode: W. M. Fawley, University of California at Berkeley, sends the following re-reduced photometric observations (cf. IAUC 2830), obtained with the Leuschner Observatory's 76-cm reflector. It is possible that v on Aug. 30 is affected (by perhaps 0.02 magnitude) by tube saturation. External errors in v and b-y are about 0.02. 1975 UT v b - y u - b v - b Aug. 30.396 1.99 +0.393 +0.95 +0.36 30.521 1.95 +0.394 +1.01 +0.38 Sept. 2.185 3.95 +0.380 +0.16 +0.07 2.267 4.12 +0.349 +0.11 +0.06 2.318 4.18 +0.346 +0.11 +0.06 2.378 4.23 +0.344 +0.09 +0.05 G. de Vaucouleurs, Department of Astronomy, University of Texas at Austin, provides the following V magnitudes, derived from visual observations by J. Bryan, P. Young and himself: Aug. 30.1 UT, 2.06: (4); 30.2, 2.00 (6); 30.3, 1.96 (4); 31.05, 1.91 (4); 31.1, 1.94 (3); 31.25, 1.92 (2); Sept. 1.05, 2.07 (2); 1.1, 2.34 (2); 1.4, 2.88 (4); 2.05, 3.64 (2); 2.15, 3.63 (5); 2.4, 4.16 (4); 3.1, 4.50 (7); 3.25, 4.36 (2); 3.4, 4.57 (5); 4.1, 4.75 (6). The figures in parentheses are the number of observations n, and the mean error is then 0.05/n**0.5. From the exceptionally fast decay Dr. de Vaucouleurs deduces that M_v = -9.5 at maximum, and allowing for absorption of 1.0 magnitude, he derives the nova's distance as about 1.6 kpc. M. S. Burkhead, Department of Astronomy, Indiana University, communicates the following preliminary photometric observations: 1975 UT V B - V U - B V - R V - I Sept. 2.131 3.61 +0.4 -0.3 +1.4 +1.8 3.116 4.41 +0.4 -0.4 +1.8 +1.9 4.227 5.02 +0.4 -0.5 +2.1 +1.8 The following photometric observations were made by J. Krempec at the Torun Observatory: 1975 UT V B - V 1975 UT V B - V Aug. 30.8 2.70 Sept. 2.8 3.66 +0.94 31.8 2.58 3.8 4.08 +0.99 Sept. 1.8 3.41 +0.31 E. P. Ney and B. Hatfield, University of Minnesota, report the following magnitude observations, made on Sept. 4.0 UT: V = 5.2, R = 3.7, I = 3.2, 2.6 at 1.2 um, 2.6 at 1.6 um, 2.1 at 2.2 um, 1.0 at 3.5 um, 0.4 at 4.8 um, -0.3 at 8.5 um, -0.5 at 10.6 um, -1.1 at 12.5 um. The following recent visual magnitude estimates have been reported: Sept. 5.06 UT, 5.0 (W. Nissen, Arlington, Virginia); 5.06, 5.5 (L. Jacchia, Cambridge, Massachusetts); 5.07, 5.2 (D. di Cicco, Waltham, Massachusetts); 5.07, 5.0 (C. Sherrod, North Little Rock, Arkansas); 5.12, 4.8 (P. Maley, Houston, Texas); 6.02, 5.7 (Jacchia); 6.12, 4.9 (Maley); 7.08, 5.9 (Sherrod); 7.08, 5.2 (Maley); 8.07, 6.3 (Sherrod); 8.08, 6.1 (Jacchia); 9.06, 6.5 (Sherrod). A. B. Hull, Flower and Cook Observatory, sends the following polarization measures, obtained between Sept. 5.08 and 5.34 UT: at 3800 A, 1.26 percent in p.a. 52o, 1.20 percent in 52o, 1.02 percent in 49o; at 4300 A, 1.31 percent in 47o, 1.38 percent in 47o; at 5400 A, 1.36 percent in 46o, 1.20 percent in 46o; at 6600 A, 1.04 percent in 50o, 1.04 percent in 51o. A. Woszczyk, Torun Observatory, communicates: "A large number of spectrograms were obtained between Aug. 29 and Sept. 4 by A. Burnicki, W. Iwanowska, S. Krawczyk, A. Strobel and myself with the Canadian Copernicus grating spectrograph attached to the Torun 90-cm Schmidt-Cassegrain telescope. The dispersion is 28 A/mm and the range 3560-5050 A. On Aug. 29.884 UT there was a strong continuum and barely visible traces of very weak and flat Balmer absorption lines blueshifted by about 1100 km/s. The mean expansion velocity of this absorption feature grew rapidly, reaching 1300 km/s on Aug. 30.13, 1500 km/s on Aug. 30.9, 2100 km/s on Aug. 31.9, and it stabilized at 2250 km/s between Sept. 1 and 4. The interstellar Ca II lines were very fine and showed a velocity of about zero. Since Aug. 30 very wide (total widths 3000 to 3400 km/s) emission lines have appeared, and their intensities have been growing rapidly from day to day. The following lines have been found: H-beta to H_10; Fe II 5018, 4924, 4296, 4233, 4179 A; a very large and complex emission feature centered at 4570 A that is certainly due to Fe II 4630, 4584, 4549 and 4520 A. Fe II 4385 A is partially blended with H-gamma. Beginning on Sept. 2 the emission lines showed a complex four-component structure that became more and more accentuated." J. B. Hutchings, Dominion Astrophysical Observatory, writes that spectrograms obtained on Aug. 31 and Sept. 1 (dispersions 2.5 to 15 A/mm) show broad H and Fe II emissions (+/- 2500 km/s) and weak absorptions at -2500 and -4000 km/s. Ca II had broad absorptions at -2000 km/s. The low-velocity absorption weakened and increased by ~ 200 km/s between the two nights. E. Mannery, University of Washington, reports that observations by R. Schommer on Sept. 4.2 UT (dispersion 60 A/mm) showed broad Balmer emission lines, each with three narrow absorption lines superimposed. Title: Nova Sagittarii 1974. Authors: Jones, A. F.; Mayer, E.; Morrison, P.; Young; Shanklin; Burch; Elias, D. P.; Simmons, K.; Vidal, N. Bibcode: 1974IAUC.2720....1J Altcode: No abstract at ADS Title: Nouveau Pas Vers La Solution du Probleme Solaire Authors: Young Bibcode: 1897BSAFR..11..402Y Altcode: No abstract at ADS Title: Auszug aus einem Briefe des Herrn Dr. Young, Secretair des Board of Longitude, an den Herausgeber Authors: Young Bibcode: 1822AN......1..463Y Altcode: 1823AN......1..463Y No abstract at ADS