Author name code: anan ADS astronomy entries on 2022-09-14 =author:"Anan, Tetsu" ------------------------------------------------------------------------ Title: Development of Integral Field Spectrographs to Revolutionize Spectroscopic Observations of Solar Flares and other Energetic Solar Eruptions Authors: Lin, Haosheng; Anan, Tetsu; Cauzzi, Gianna; Fletcher, Lyndsay; Huang, Pei; Kowalski, Adam; Kramar, Maxim; Qiu, Jiong; Samra, Jenna; Spittler, Constance; Sukegawa, Takashi; Wirth, Gregory Bibcode: 2022arXiv220900788L Altcode: The Sun's proximity offers us a unique opportunity to study in detail the physical processes on a star's surface; however, the highly dynamic nature of the stellar surface -- in particular, energetic eruptions such as flares and coronal mass ejections -- presents tremendous observational challenges. Spectroscopy probes the physical state of the solar atmosphere, but conventional scanning spectrographs and spectrometers are unable to capture the full evolutionary history of these dynamic events with a sufficiently wide field of view and high spatial, spectral, and temporal resolution. Resolving the physics of the dynamic sun requires gathering simultaneous spectra across a contiguous area over the full duration of these events, a goal now tantalizingly close to achievable with continued investment in developing powerful new Integral Field Spectrographs to serve as the foundation of both future ground- and space-based missions. This technology promises to revolutionize our ability to study solar flares and CMEs, addressing NASA's strategic objective to "understand the Sun, solar system, and universe." Since such events generate electromagnetic radiation and high-energy particles that disrupt terrestrial electric infrastructure, this investment not only advances humanity's scientific endeavors but also enhances our space weather forecasting capability to protect against threats to our technology-reliant civilization. Title: Ground-based instrumentation and observational techniques Authors: Rimmele, Thomas; Kuhn, Jeff; Woeger, Friedrich; Tritschler, . Alexandra; Lin, Haosheng; Casini, Roberto; Schad, Thomas; Jaeggli, Sarah; de Wijn, Alfred; Fehlmann, Andre; Anan, Tetsu; Schmidt, Dirk Bibcode: 2022cosp...44.2507R Altcode: We'll review the current state-of-the-art for ground-based instrumentation and techniques to achieve high-resolution observations. We'll use the 4m Daniel K. Inouye Solar Telescope (DKIST), the European Solar Telescope (EST) and other ground-based instrumentation as examples to demonstrate instrument designs and observing techniques. Using adaptive optics and post-facto image processing techniques, the recently completed DKIST provides unprecedented resolution and high polarimetric sensitivity that enables astronomers to unravel many of the mysteries the Sun presents, including the origin of solar magnetism, the mechanisms of coronal heating and drivers of flares and coronal mass ejections. Versatile ground-based instruments provide highly sensitive measurements of solar magnetic fields, that in the case of DKIST, also include measurements of the illusive magnetic field of the faint solar corona. Ground-based instruments produce large and diverse data sets that require complex calibration and data processing to provide science-ready to a broad community. We'll briefly touch on ongoing and future instrumentation developments, including multi-conjugate adaptive optics. Title: Science Commissioning of the Diffraction-Limited Near-IR Spectropolarimter for the Daniel K. Inouye Solar Telescope Authors: Lin, Haosheng; Schad, Thomas; Kramar, Maxim; Jaeggli, Sarah; Anan, Tetsu; Onaka, Peter Bibcode: 2022cosp...44.2508L Altcode: The Diffraction-Limited Near-IR Spectropolarimeter (DL-NIRSP) is one of the first-generation facility instruments of the Daniel K. Inouye Solar Telescope (DKIST, or The Inouye Solar Telescope). It is a near-IR spectropolarimeter optimized to study the magnetism of the dynamic solar atmosphere, from the photosphere to the corona. DL-NIRSP is equipped with two integral field units (IFUs) coupled to a high-resolution grating spectrograph, and is capable of simultaneous measurements of the full polarized spectra of a 2-dimensional spatial field without scanning. Large field of view observations are supported by mosaicking. DL-NIRSP observes simultaneously at three spectral windows, enabling simultaneous coverage of different atmospheric layers with carefully selected spectral lines. It can also observe the Sun with three resolution modes, from diffraction-limited observations with a spatial sampling of 0.03" to wide-field mode covering a 32"x15" instantaneous FOV with 0.5" sampling. This paper will present results from science commissioning observations conducted in late 2021. Title: Chromospheric Heating Mechanisms in a Plage Region Constrained by Comparison of Magnetic Field and Mg II h & k Flux Measurements with Theoretical Studies Authors: Anan, Tetsu; Schad, Thomas; Kitai, Reizaburo; Dima, Gabriel; Jaeggli, Sarah; Tarr, Lucas; Collados, Manuel; Dominguez-Tagle, Carlos; Kleint, Lucia Bibcode: 2021AGUFMSH44A..05A Altcode: The strongest quasi-steady heating in the solar atmosphere from the photosphere through the corona occurs in plage regions. As many chromospheric heating mechanisms have been proposed, important discriminators of the possible mechanisms are the location of the heating and the correlation between the magnetic field properties in the chromosphere and the local heating rate. We observed a plage region with the He I 1083.0 nm and Si I 1082.7 nm lines on 2018 October 3 using the integral field unit mode of the GREGOR Infrared Spectrograph (GRIS) installed at the GREGOR telescope. During the GRIS observation, the Interface Region Imaging Spectrograph (IRIS) obtained spectra of the ultraviolet Mg II h & k doublet emitted from the same region. In the periphery of the plage region, within the limited field of view seen by GRIS, we find that the Mg II radiative flux increases with the magnetic field in the chromosphere. The positive correlation implies that magnetic flux tubes can be heated by Alfvén wave turbulence or by collisions between ions and neutral atoms relating to Alfvén waves. Within the plage region itself, the radiative flux was large between patches of strong magnetic field strength in the photosphere, or at the edges of magnetic patches. On the other hand, we do not find any significant spatial correlation between the enhanced radiative flux and the chromospheric magnetic field strength or the electric current. In addition to the Alfvén wave turbulence or collisions between ions and neutral atoms relating to Alfvén waves, other heating mechanisms related to magnetic field perturbations produced by interactions of magnetic flux tubes could be at work in the plage chromosphere. Title: Measurements of Photospheric and Chromospheric Magnetic Field Structures Associated with Chromospheric Heating over a Solar Plage Region Authors: Anan, Tetsu; Schad, Thomas A.; Kitai, Reizaburo; Dima, Gabriel I.; Jaeggli, Sarah A.; Tarr, Lucas A.; Collados, Manuel; Dominguez-Tagle, Carlos; Kleint, Lucia Bibcode: 2021ApJ...921...39A Altcode: 2021arXiv210807907A In order to investigate the relation between magnetic structures and the signatures of heating in plage regions, we observed a plage region with the He I 1083.0 nm and Si I 1082.7 nm lines on 2018 October 3 using the integral field unit mode of the GREGOR Infrared Spectrograph (GRIS) installed at the GREGOR telescope. During the GRIS observation, the Interface Region Imaging Spectrograph obtained spectra of the ultraviolet Mg II doublet emitted from the same region. In the periphery of the plage region, within the limited field of view seen by GRIS, we find that the Mg II radiative flux increases with the magnetic field in the chromosphere with a factor of proportionality of 2.38 × 104 erg cm-2 s-1 G-1. The positive correlation implies that magnetic flux tubes can be heated by Alfvén wave turbulence or by collisions between ions and neutral atoms relating to Alfvén waves. Within the plage region itself, the radiative flux was large between patches of strong magnetic field strength in the photosphere or at the edges of magnetic patches. On the other hand, we do not find any significant spatial correlation between the enhanced radiative flux and the chromospheric magnetic field strength or the electric current. In addition to the Alfvén wave turbulence or collisions between ions and neutral atoms relating to Alfvén waves, other heating mechanisms related to magnetic field perturbations produced by interactions of magnetic flux tubes could be at work in the plage chromosphere. Title: He I Spectropolarimetry of a Supersonic Coronal Downflow Within a Sunspot Umbra Authors: Schad, Thomas A.; Dima, Gabriel I.; Anan, Tetsu Bibcode: 2021ApJ...916....5S Altcode: We report spectropolarimetric observations of a supersonic downflow impacting the lower atmosphere within a large sunspot umbra. This work is an extension of Schad et al. using observations acquired in the He I 10830 Å triplet by the Facility Infrared Spectropolarimeter. Downflowing material accelerating along a cooled coronal loop reaches peak speeds near 200 km s-1 and exhibits both high speed emission and absorption within the umbra, which we determine to be a consequence of the strong height dependence of the radiatively controlled source function above the sunspot umbra. Strong emission profiles close to the rest wavelengths but with long redshifted tails are also observed at the downflow terminus. From the polarized spectra, we infer longitudinal magnetic field strengths of ~2.4 kG in the core portion of the He I strong emission, which we believe is the strongest ever reported in this line. Photospheric field strengths along the same line of sight are ~2.8 kG as inferred using the Ca I 10839 Å spectral line. The temperatures of the highest speed He I absorption and the near-rest emission are similar (~10 kK), while a differential emission measure analysis using Solar Dynamics Observatory/Atmospheric Imaging Assembly data indicates significant increases in radiative cooling for temperatures between ~0.5 and 1 MK plasma associated with the downflow terminus. Combined we interpret these observations in the context of a strong radiative shock induced by the supersonic downflow impacting the low sunspot atmosphere. Title: He I spectropolarimetry of a supersonic coronal downflow within a sunspot umbra Authors: Schad, Thomas A.; Dima, Gabriel I.; Anan, Tetsu Bibcode: 2021arXiv210512853S Altcode: We report spectropolarimetric observations of a supersonic downflow impacting the lower atmosphere within a large sunspot umbra. This work is an extension of Schad et al. 2016 using observations acquired in the He I 10830 Angstrom triplet by the Facility Infrared Spectropolarimeter. Downflowing material accelerating along a cooled coronal loop reaches peak speeds near 200 km s$^{-1}$ and exhibits both high speed emission and absorption within the umbra, which we determine to be a consequence of the strong height dependence of the radiatively-controlled source function above the sunspot umbra. Strong emission profiles close to the rest wavelengths but with long red-shifted tails are also observed at the downflow terminus. From the polarized spectra, we infer longitudinal magnetic field strengths of ${\sim}2.4$ kG in the core portion of the He I strong emission, which we believe is the strongest ever reported in this line. Photospheric field strengths along the same line-of-sight are ${\sim}2.8$ kG as inferred using the Ca I 10839 Angstrom spectral line. The temperatures of the highest speed He I absorption and the near rest emission are similar (${\sim}$10 kK), while a differential emission measure analysis using SDO/AIA data indicates significant increases in radiative cooling for temperatures between $\sim$0.5 and 1 MK plasma associated with the downflow terminus. Combined we interpret these observations in the context of a strong radiative shock induced by the supersonic downflow impacting the low sunspot atmosphere. Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for SUNRISE III: polarization modulation unit Authors: Kubo, Masahito; Shimizu, Toshifumi; Katsukawa, Yukio; Kawabata, Yusuke; Anan, Tetsu; Ichimoto, Kiyoshi; Shinoda, Kazuya; Tamura, Tomonori; Nodomi, Yoshifumi; Nakayama, Satoshi; Yamada, Takuya; Tajima, Takao; Nakata, Shimpei; Nakajima, Yoshihito; Okutani, Kousei; Feller, Alex; del Toro Iniesta, Jose Carlos Bibcode: 2020SPIE11447E..A3K Altcode: Polarization measurements of the solar chromospheric lines at high precision are key to present and future solar telescopes for understanding magnetic field structures in the chromosphere. The Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for Sunrise III is a spectropolarimeter with a polarimetric precision of 0.03 % (1 σ). The key to high-precision polarization measurements using SCIP is a polarization modulation unit that rotates a waveplate continuously at a constant speed. The rotating mechanism is a DC brushless motor originally developed for a future space mission, and its control logic was originally developed for the sounding rocket experiment CLASP. Because of our requirement on a speed of rotation (0.512 s/rotation) that was 10 times faster than that of CLASP, we optimized the control logic for the required faster rotation. Fast polarization modulation is essential for investigating the fine-scale magnetic field structures related to the dynamical chromospheric phenomena. We have verified that the rotation performance can achieve the polarization precision of 0.03 % (1 σ) required by SCIP and such a significant rotation performance is maintained under thermal vacuum conditions by simulating the environment of the Sunrise III balloon flight. The waveplate was designed as a pair of two birefringent plates made of quartz and sapphire to achieve a constant retardation in a wide wavelength range. We have confirmed that the retardation is almost constant in the 770 nm and 850nm wavelength bands of SCIP under the operational temperature conditions. Title: The Daniel K. Inouye Solar Telescope - Observatory Overview Authors: Rimmele, Thomas R.; Warner, Mark; Keil, Stephen L.; Goode, Philip R.; Knölker, Michael; Kuhn, Jeffrey R.; Rosner, Robert R.; McMullin, Joseph P.; Casini, Roberto; Lin, Haosheng; Wöger, Friedrich; von der Lühe, Oskar; Tritschler, Alexandra; Davey, Alisdair; de Wijn, Alfred; Elmore, David F.; Fehlmann, André; Harrington, David M.; Jaeggli, Sarah A.; Rast, Mark P.; Schad, Thomas A.; Schmidt, Wolfgang; Mathioudakis, Mihalis; Mickey, Donald L.; Anan, Tetsu; Beck, Christian; Marshall, Heather K.; Jeffers, Paul F.; Oschmann, Jacobus M.; Beard, Andrew; Berst, David C.; Cowan, Bruce A.; Craig, Simon C.; Cross, Eric; Cummings, Bryan K.; Donnelly, Colleen; de Vanssay, Jean-Benoit; Eigenbrot, Arthur D.; Ferayorni, Andrew; Foster, Christopher; Galapon, Chriselle Ann; Gedrites, Christopher; Gonzales, Kerry; Goodrich, Bret D.; Gregory, Brian S.; Guzman, Stephanie S.; Guzzo, Stephen; Hegwer, Steve; Hubbard, Robert P.; Hubbard, John R.; Johansson, Erik M.; Johnson, Luke C.; Liang, Chen; Liang, Mary; McQuillen, Isaac; Mayer, Christopher; Newman, Karl; Onodera, Brialyn; Phelps, LeEllen; Puentes, Myles M.; Richards, Christopher; Rimmele, Lukas M.; Sekulic, Predrag; Shimko, Stephan R.; Simison, Brett E.; Smith, Brett; Starman, Erik; Sueoka, Stacey R.; Summers, Richard T.; Szabo, Aimee; Szabo, Louis; Wampler, Stephen B.; Williams, Timothy R.; White, Charles Bibcode: 2020SoPh..295..172R Altcode: We present an overview of the National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST), its instruments, and support facilities. The 4 m aperture DKIST provides the highest-resolution observations of the Sun ever achieved. The large aperture of DKIST combined with state-of-the-art instrumentation provide the sensitivity to measure the vector magnetic field in the chromosphere and in the faint corona, i.e. for the first time with DKIST we will be able to measure and study the most important free-energy source in the outer solar atmosphere - the coronal magnetic field. Over its operational lifetime DKIST will advance our knowledge of fundamental astronomical processes, including highly dynamic solar eruptions that are at the source of space-weather events that impact our technological society. Design and construction of DKIST took over two decades. DKIST implements a fast (f/2), off-axis Gregorian optical design. The maximum available field-of-view is 5 arcmin. A complex thermal-control system was implemented in order to remove at prime focus the majority of the 13 kW collected by the primary mirror and to keep optical surfaces and structures at ambient temperature, thus avoiding self-induced local seeing. A high-order adaptive-optics system with 1600 actuators corrects atmospheric seeing enabling diffraction limited imaging and spectroscopy. Five instruments, four of which are polarimeters, provide powerful diagnostic capability over a broad wavelength range covering the visible, near-infrared, and mid-infrared spectrum. New polarization-calibration strategies were developed to achieve the stringent polarization accuracy requirement of 5×10−4. Instruments can be combined and operated simultaneously in order to obtain a maximum of observational information. Observing time on DKIST is allocated through an open, merit-based proposal process. DKIST will be operated primarily in "service mode" and is expected to on average produce 3 PB of raw data per year. A newly developed data center located at the NSO Headquarters in Boulder will initially serve fully calibrated data to the international users community. Higher-level data products, such as physical parameters obtained from inversions of spectro-polarimetric data will be added as resources allow. Title: Shock Heating Energy of Umbral Flashes Measured with Integral Field Unit Spectroscopy Authors: Anan, Tetsu; Schad, Thomas A.; Jaeggli, Sarah A.; Tarr, Lucas A. Bibcode: 2019ApJ...882..161A Altcode: 2019arXiv190710797A Umbral flashes are periodic brightness increases routinely observed in the core of chromospheric lines within sunspot umbrae and are attributed to propagating shock fronts. In this work we quantify the shock heating energy of these umbral flashes using observations in the near-infrared He I triplet obtained on 2014 December 7 with the SpectroPolarimetric Imager for the Energetic Sun, which is a novel integral field unit spectrograph at the Dunn Solar Telescope. We determine the shock properties (the Mach number and the propagation speed) by fitting the measured He I spectral profiles with a theoretical radiative transfer model consisting of two constant-property atmospheric slabs whose temperatures and macroscopic velocities are constrained by the Rankine-Hugoniot relations. From the Mach number, the shock heating energy per unit mass of plasma is derived to be 2 × 1010 erg g-1, which is insufficient to maintain the umbral chromosphere. In addition, we find that the shocks propagate upward with the sound speed and the Mach number does not depend on the temperature upstream of the shocks. The latter may imply suppression of the amplification of the Mach number due to energy loss of the shocks. Title: Optical Alignment of DL-NIRSP Spectrograph Authors: Jaeggli, Sarah A.; Anan, Tetsu; Kramar, Maxim; Lin, Haosheng Bibcode: 2019AAS...23410612J Altcode: The Diffraction-Limited Near-Infrared Spectropolarimeter (DL-NIRSP) will be delivered as part of the first light instrumentation for the Daniel K. Inouye Solar Telescope (DKIST) and is currently undergoing lab integration at the University of Hawai'i Institute for Astronomy's Advanced Technology Research Center on Maui. An off-axis hyperbolic mirror, with a focal length of 1250 mm, is used as both collimator and camera in the spectrograph, and makes this system particularly difficult to align. The optical axis, or vertex, of the parent surface is located approximately 260 mm from the center of the off-axis section of the mirror, but there is no direct physical or optical reference for the location and orientation of the optical axis. We have made use of vendor data and a coordinate measuring machine (CMM) arm to transfer coordinates from the back and perimeter surfaces of the mirror to locate the optical axis focus and place the other optical components in reference to this mechanical model. In coordination, we have conducted tests of the optical quality at various points during the alignment to ensure that the mechanical tolerances maintain the optical quality of the system so that the instrument will be able to achieve excellent spectral resolution limited by the spectrograph slit width (λ/Δλ 250,000), and preserve the diffraction limited spatial resolution provided by the telescope and feed optics (0.06" at 1 μm). Title: Shock heating energy in an umbra of a sunspot with integral field unit spectroscopy Authors: Anan, Tetsu; Schad, Thomas A.; Jaeggli, Sarah A.; Tarr, Lucas A. Bibcode: 2019AAS...23421705A Altcode: On 2014 December 7 we used new integral field spectroscopy techniques to observe umbral flashes, which are periodic brightness increases routinely observed in the core of chromospheric lines within sunspot umbrae and are attributed to propagating shock fronts. In this work we quantify the shock heating energy of these umbral flashes using observations in the near infrared HeI triplet obtained with the SpectroPolarimetric Imager for the Energetic Sun (SPIES), which is novel integral field unit spectrograph at the Dunn Solar Telescope. We determine the shock properties (the Mach number and the propagation speed) by fitting the measured HeI spectral profiles with a theoretical radiative transfer model using two constant property atmospheric slabs whose temperatures and macroscopic velocities are constrained by the Rankine-Hugoniot relations. From the Mach number, the shock heating energy per unit mass of plasma is derived as 2 x 1010 erg/g. We conclude that the estimated shock heating energy rate is less than the amount required to maintain the umbral chromosphere. Title: Shock Heating Energy in an umbra of a sunspot Authors: Anan, Tetsu; Schad, Tom; Jaeggli, Sarah Bibcode: 2019EGUGA..2113543A Altcode: In December 7, 2014, umbral flashes, which are periodic brightness increases in chromospheric spectral lines of the umbrae due to shocks, were observed in near infrared He I triplet with an integral-field-unit spectrometer, SPIES (SpectroPolarimetric Imager for the Energetic Sun) on the Dunn Solar Telescope with a cadence of 14 seconds. The SPIES is a prototype instruments of a facility instrument of the Daniel K. Inouye Solar Telescope. In order to determine Mach number at upstream of shock waves, we fit the measured spectral profiles in the He I 1083 nm triplet with theoretical profiles computed with a radiative transfer equation using an atmospheric model based on two constant property slabs, of which temperatures and macroscopic velocities are constrained by the Rankine-Hugoniot relations. From the Mach number and the temperature, shock heating energy per unit mass of plasma is derived as 2.0 x 10 ^ {10} erg/g. Finding a positive correlation between a spatial variation of the chromospheric temperature and shock speed, we concluded that prominent heating mechanism can be related with the shock, although estimated shock heating energy rate is less than the required amount of energy to maintain the umbral chromosphere. Title: Developments of a multi-wavelength spectro-polarimeter on the Domeless Solar Telescope at Hida Observatory Authors: Anan, Tetsu; Huang, Yu-Wei; Nakatani, Yoshikazu; Ichimoto, Kiyoshi; UeNo, Satoru; Kimura, Goichi; Ninomiya, Shota; Okada, Sanetaka; Kaneda, Naoki Bibcode: 2018PASJ...70..102A Altcode: 2018arXiv180302094A; 2018PASJ..tmp...66A To obtain full Stokes spectra in multi-wavelength windows simultaneously, we developed a new spectro-polarimeter on the Domeless Solar Telescope at Hida Observatory. The new polarimeter consists of a 60 cm aperture vacuum telescope on an altazimuth mounting, an image rotator, a high-dispersion spectrograph, and a polarization modulator and an analyzer composed of a continuously rotating waveplate with a retardation that is nearly constant at around 127° in 500-1100 nm. There are also a polarizing beam splitter located close behind the focus of the telescope, fast and large format CMOS cameras, and an infrared camera. A slit spectrograph allows us to obtain spectra in as many wavelength windows as the number of cameras. We characterized the instrumental polarization of the entire system and established a polarization calibration procedure. The cross-talks among the Stokes Q, U, and V have been evaluated to be about 0.06%-1.2%, depending on the degree of the intrinsic polarizations. In a typical observing setup, a sensitivity of 0.03% can be achieved in 20-60 seconds for 500-1100 nm. The new polarimeter is expected to provide a powerful tool for diagnosing the 3D magnetic field and other vector physical quantities in the solar atmosphere. Title: Measurement of vector magnetic field in a flare kernel with a spectropolarimetric observation in He I 10830 Å Authors: Anan, Tetsu; Yoneya, Takurou; Ichimoto, Kiyoshi; UeNo, Satoru; Shiota, Daikou; Nozawa, Satoshi; Takasao, Shinsuke; Kawate, Tomoko Bibcode: 2018PASJ...70..101A Altcode: 2018arXiv180806821A; 2018PASJ..tmp..113A A flare kernel associated with a C4 class flare was observed in a spectral window including the He I triplet 10830 Å and Si I 10827 Å with a spectropolarimeter on the Domeless Solar Telescope at Hida Observatory on 2015 August 9. The observed Stokes profiles of the He I triplet in the flare kernel in its post-maximum phase are well reproduced through inversions considering the Zeeman and the Paschen-Back effects with a three-slab model of the flare kernel, in which two slabs which have upward and downward velocities produce emissions and one slab produces an absorption. The magnetic field strength inferred from the emission components of the He I line is 1400 G, which is significantly stronger than 690 G that is observed at the same location in the same line 6.5 hr before the flare. In addition, the photospheric magnetic field vector derived from the Si I10827 Å is similar to that of the flare kernel. To explain this result, we suggest that the emission in the He I triplet during the flare is produced in the deep layer, around which bombardment of non-thermal electrons leads to the formation of a coronal temperature plasma. Assuming a hydrogen column density at the location where the He I emissions are formed, and a power-law index of non-thermal electron energy distribution, we derived the low-energy cutoff of the non-thermal electron as 20-30 keV, which is consistent with that inferred from hard X-ray data obtained by RHESSI. Title: Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) for the SUNRISE balloon-borne solar observatory Authors: Suematsu, Yoshinori; Katsukawa, Yukio; Hara, Hirohisa; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Kubo, Masahito; Barthol, Peter; Riethmueller, Tino; Gandorfer, Achim; Feller, Alex; Orozco Suárez, David; Del Toro Iniesta, Jose Carlos; Kano, Ryouhei; Ishikawa, Shin-nosuke; Ishikawa, Ryohko; Tsuzuki, Toshihiro; Uraguchi, Fumihiro; Quintero Noda, Carlos; Tamura, Tomonori; Oba, Takayoshi; Kawabata, Yusuke; Nagata, Shinichi; Anan, Tetsu; Cobos Carrascosa, Juan Pedro; Lopez Jimenez, Antonio Carlos; Balaguer Jimenez, Maria; Solanki, Sami Bibcode: 2018cosp...42E3285S Altcode: The SUNRISE balloon-borne solar observatory carries a 1 m aperture optical telescope, and allows us to perform seeing-free continuous observations at visible-IR wavelengths from an altitude higher than 35 km. In the past two flights, in 2009 and 2013, observations mainly focused on fine structures of photospheric magnetic fields. For the third flight planned for 2021, we are developing a new instrument for conducting spectro-polarimetry of spectral lines formed over a larger height range in the solar atmosphere from the photosphere to the chromosphere. Targets of the spectro-polarimetric observation are (1) to determine 3D magnetic structure from the photosphere to the chromosphere, (2) to trace MHD waves from the photosphere to the chromosphere, and (3) to reveal the mechanism driving chromospheric jets, by measuring height- and time-dependent velocities and magnetic fields. To achieve these goals, a spectro-polarimeter called SCIP (Sunrise Chromospheric Infrared spectroPolarimeter) is designed to observe near-infrared spectrum lines sensitive to solar magnetic fields. The spatial and spectral resolutions are 0.2 arcsec and 200,000, respectively, while 0.03% polarimetric sensitivity is achieved within a 10 sec integration time. The optical system employs an Echelle grating and off-axis aspheric mirrors to observe the two wavelength ranges centered at 850 nm and 770 nm simultaneously by two cameras. Polarimetric measurements are performed using a rotating waveplate and polarization beam-splitters in front of the cameras. For detecting minute polarization signals with good precision, we carefully assess the temperature dependence of polarization optics, and make the opto-structural design that minimizes the thermal deformation of the spectrograph optics. Another key technique is to attain good (better than 30 msec) synchronization among the rotating phase of the waveplate, read-out timing of cameras, and step timing of a slit-scanning mirror. On-board accumulation and data processing are also critical because we cannot store all the raw data read-out from the cameras. We demonstrate that we can reduce the data down to almost 10% with loss-less image compression and without sacrificing polarimetric information in the data. The SCIP instrument is developed by internal collaboration among Japanese institutes including Japan Aerospace Exploration Agency (JAXA), the Spanish Sunrise consortium, and the German Max Planck Institute for Solar System Research (MPS) with a leadership of the National Astronomical Observatory of Japan (NAOJ). Title: Development of a near-infrared detector and a fiber-optic integral field unit for a space solar observatory SOLAR-C Authors: Katsukawa, Yukio; Kamata, Yukiko; Anan, Tetsu; Hara, Hirohisa; Suematsu, Yoshinori; Bando, Takamasa; Ichimoto, Kiyoshi; Shimizu, Toshifumi Bibcode: 2016SPIE.9904E..5IK Altcode: We are developing a high sensitivity and fast readout near-infrared (NIR) detector and an integral field unit (IFU) for making spectro-polarimetric observations of rapidly varying chromospheric spectrum lines, such as He I 1083 nm and Ca II 854 nm, in the next space-based solar mission SOLAR-C. We made tests of a 1.7 μm cutoff H2RG detector with the SIDECAR ASIC for the application in SOLAR-C. It's important to verify its perfor- mance in the temperature condition around -100 °C, which is hotter than the typical temperature environment used for a NIR detector. We built a system for testing the detector between -70 °C and -140 °C. We verified linearity, read-out noise, and dark current in both the slow and fast readout modes. We found the detector has to be cooled down lower than -100 °C because of significant increase of the number of hot pixels in the hotter environment. The compact and polarization maintenance IFU was designed using fiber-optic ribbons consisting of rectangular cores which exhibit good polarization maintenance. A Silicone adhesive DC-SE9187L was used to hold the fragile fiber-optic ribbons in a metal housing. Polarization maintenance property was confirmed though polarization calibration as well as temperature control are required to suppress polarization crosstalk and to achieve the polarization accuracy in SOLAR-C. Title: Developments of the wideband spectropolarimeter of the Domeless Solar Telescope at Hida Observatory Authors: Anan, Tetsu; Ichimoto, Kiyoshi; Oi, Akihito; Kimura, Goichi; Nakatani, Yoshikazu; Ueno, Satoru Bibcode: 2012SPIE.8446E..1CA Altcode: We developed a new universal spectropolarimeter on the Domeless Solar Telescope at Hida Observatory to realize precise spectropolarimetric observations in a wide range of wavelength in visible and near infrared. The system aims to open a new window of plasma diagnostics by using Zeeman effect, Hanle effect, Stark effect, and impact polarization to measure the external magnetic field, electric field, and anisotropies in atomic excitation in solar atmosphere. The polarimeter consists of a 60 cm aperture vacuum telescope, a high dispersion vacuum spectrograph, polarization modulator and analyser composed of a continuously rotating waveplate whose retardation is constant in 400 - 1100 nm and Wallaston prisms located closely behind the focus of the telescope, and a fast and high sensitive CCD camera or a infrared camera. The duration for this polarimeter's achieving photometric accuracy of 10-3 is 30 - 60 s. Instrumental polarization of the telescope is calibrated by using a remotely controllable turret accommodating linear polarizer attached at the entrance window of the telescope to induce well known polarized light into the telescope. Thus a Mueller matrix model of the telescope is established to compensate the instrumental polarization included in observed data within the required accuracy. Title: Spicule Dynamics over a Plage Region Authors: Anan, Tetsu; Kitai, Reizaburo; Kawate, Tomoko; Matsumoto, Takuma; Ichimoto, Kiyoshi; Shibata, Kazunari; Hillier, Andrew; Otsuji, Kenichi; Watanabe, Hiroko; Ueno, Satoru; Nagata, Shin'ichi; Ishii, Takako T.; Komori, Hiroyuki; Nishida, Keisuke; Nakamura, Tahei; Isobe, Hiroaki; Hagino, Masaoki Bibcode: 2010PASJ...62..871A Altcode: 2010arXiv1002.2288A We studied spicular jets over a plage area and derived their dynamic characteristics using Hinode Solar Optical Telescope (SOT) high-resolution images. A target plage region was near to the west limb of the solar disk. This location permitted us to study the dynamics of spicular jets without any overlapping effect of spicular structures along the line of sight. In this work, to increase the ease with which we could identify spicules on the disk, we applied the image processing method `MadMax' developed by Koutchmy et al. (1989). It enhances fine, slender structures (like jets), over a diffuse background. We identified 169 spicules over the target plage. This sample permited us to derive statistically reliable results regarding spicular dynamics. The properties of plage spicules can be summarized as follows: (1) In a plage area, we clearly identified spicular jet features. (2) They were shorter in length than the quiet region limb spicules, and followed a ballistic motion under constant deceleration. (3) The majority (80%) of the plage spicules showed a cycle of rise and retreat, while 10% of them faded out without a complete retreat phase. (4) The deceleration of the spicule was proportional to the velocity of ejection (i.e., the initial velocity).