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Author name code: house
ADS astronomy entries on 2022-09-14
author:"House, Lewis"
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Title: The Ejection of Helical Field Structures through the Outer
Corona
Authors: House, Lewis L.; Berger, Mitchell A.
1987ApJ...323..406H Altcode:
The May 5, 1980 coronal mass ejection observed by the SMM coronagraph
polarimeter contained an eruptive prominence with apparent helical
structure. After a general discussion of the morphology of this event,
the evolution of the prominence structure as it traversed the outer
corona is described. Particular attention is given to the distribution
of magnetic helicity, a measure of helical structure. This distribution
can be inferred by tracking the crossovers between individual filaments
within the prominence. The northern leg of the prominence consisted
of two braided H-alpha filaments shredded into subfilaments near the
top. Much of the helicity in this leg resided in a compact central
region. As the prominence rose, the central region unwound by expanding
rapidly along the leg. This expansion could arise from both acceleration
of the prominence material and spreading of the distribution of helicity
along the leg.
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Title: The type IV burst of 1980 June 29, 0233 UT - Harmonic plasma
emission?
Authors: Gary, D. E.; Dulk, G. A.; House, L. L.; Illing, R.; Wagner,
W. J.; Mclean, D. J.
1985A&A...152...42G Altcode:
The coronal transient event of 1980 June 29, 0233 UT, was well observed
by the HAO Coronagraph/Polarimeter aboard SMM and at meter radio
wavelengths by the Culgoora Radioheliograph. The radio event consisted
of a strong Type II (shock wave related) burst followed by weak Type
IV (storm) continuum. The authors discuss the details of the Type IV
portion of the event in terms of two possible emission mechanisms-plasma
emission (at the second harmonic) and gyro-synchrotron emission. They
find that gyro-synchrotron emission is a possible mechanism only if more
stringent requirements are met, viz., that the density of electrons
of energy greater than 10 keV is about 10% of the ambient density,
that the average energy is about 40 keV, and that the magnetic field
strength at 2.5 solar radii is about 2.8 gauss. The authors conclude
that this Type IV event is likely due to plasma emission at the 2nd
harmonic of the plasma frequency.
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Title: Vector Magnetic Fields in Prominences - Part Two Hei d3 Stokes
Profiles Analysis for Two Quiescent Prominences
Authors: Querfeld, C. W.; Smartt, R. N.; Bommier, V.; Landi
Degl'Innocenti, E.; House, L. L.
1985SoPh...96..277Q Altcode:
The Stokes components of He I D<SUB>3</SUB> emission in two quiescent
prominences, using full spectral profile measurements, are analyzed to
derive vector magnetic fields. Two independently developed schemes,
based on the Hanle effect, are used for interpretation. They involve
solutions of the statistical equilibrium equations for the He I
D<SUB>3</SUB> multiplet, including the effect of coherency and full
level crossing, which predict the magnetic field dependence of the
observed polarization. Derived magnetic field vector solutions for
each pair of linear polarization Stokes profiles corresponding to
an observational point in the prominence are, intrinsically, not
uniquely determined, and a set of possible solutions is usually
obtained. However, mutual consistency of these solutions with
those independently predicted by the form of the circular polarized
component, allow, in almost all cases, rejection of all solutions of a
set except one symmetrical pair. Of such a pair, a unique solution can
be determined with a high confidence level by reference to independent
potential field information. Field vectors are found usually to be
close to horizontal and normal to the prominence surface, but extreme
exceptions are found. Field values range from 6 G to 60 G. The derived
vectorfield configurations and their magnitudes are briefly discussed
relative to these prominences and to different quiescent prominence
models.
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Title: Type II bursts, shock waves, and coronal transients - The
event of 1980 June 29, 0233 UT
Authors: Gary, D. E.; Dulk, G. A.; House, L.; Illing, R.; Sawyer,
C.; Wagner, W. J.; McLean, D. J.; Hildner, E.
1984A&A...134..222G Altcode:
The metric Type-II solar burst event of June 29, 1980, is characterized
on the basis of spatially resolved radioheliograph observations
obtained at Culgoora, Australia, and visible-light observations
obtained with the coronograph/polarimeter of the SMM satellite. The
data are presented in images, diagrams, and graphs and discussed in
detail. The Type-II emission is found to arise in the dense moving
material behind the transient loops, which have sky-plane width 0.5
solar radius and line-of-sight depth 0.1-0.4 solar radius. A faint arc
observed moving ahead of the transient loops at about 900 km/sec and
not associated with the Type-II burst is attributed to a shock front,
and the compression ratio and Alfven Mach number of the enhanced-density
region are estimated as n2/n1 = 1.3-3 and M(A) = 1.2-3. The ambient
material at 3 solar radii is determined to have Alfven speed 250-625
km/sec and magnetic-field strength 50-120 mG. The total mass of the
event is calculated as 700 Tg; the total magnetic energy of the loops is
(1.5-15) x 10 to the 29th ergs.
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Title: Coronal mass ejections observed during the solar maximum
mission: Latitude distribution and rate of occurrence
Authors: Hundhausen, A. J.; Sawyer, C. B.; House, L.; Illing, R. M. E.;
Wagner, W. J.
1984JGR....89.2639H Altcode:
Sixty-five coronal mass ejections have been identified in a systematic
examination of white-light coronal images obtained between March and
September 1980 by the coronagraph/polarimeter flown on the solar maximum
mission spacecraft. These ejections were more uniformly distributed
in position angle (or “projected” solar latitude) than the similar
events observed during the Skylab mission in 1973-1974 27% of the solar
maximum mission mass ejections were centered at positions more than 45°
from the solar equator. The average rate of occurrence of the observed
mass ejections for the entire solar maximum mission epoch, based on the
assumption that one coronagraph image per spacecraft orbit is sufficient
for detection, was 0.9+/-0.15 per 24-hour day. Application of the same
sampling assumption to the Skylab data set leads to a rate of 0.75
per 24-hour day and thus a change in this rate from the Skylab era
(on the declining phase of sunspot cycle 20) to solar maximum mission
(near the maximum of sunspot cycle 21) of only ~20%.
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Title: Coronal transients and their interplanetary effects.
Authors: Hundhausen, A. J.; Burlaga, L. F.; Feldman, W. C.; Gosling,
J. T.; Hildner, E.; House, L. L.; Howard, R. A.; Krieger, A. S.;
Kundu, M. R.; Low, B. C.; Sheeley, N. R., Jr.; Steinolfson, R. S.;
Stewart, R. T.; Stone, R. G.; Wu, S. T.
1984NASRP1120....6H Altcode:
Contents: 1. Introduction. 2. Background material: Ancient history -
solar flares and geomagnetic storms. Modern history - interplanetary
shock waves. Coronal transients or mass ejections. 3. The present:
Theoretical models. New observations of coronal mass ejections. 4. The
future: Solar origins. Interplanetary effects.
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Title: Vector Magnetic Fields in Prominences: Observations and
Analysis
Authors: Smartt, R. N.; House, L. L.
1984KodOB...4...35S Altcode:
Stokes polarimeter spectral profiles of He I D<SUB>3</SUB>, representing
many observational points within a quiescent prominence, are interpreted
using a detailed quantum-mechanical theory of resonance polarization
for the D<SUB>3</SUB> multiplet. The multiple set of solutions obtained
when the linear polarization information alone is used can be reduced,
generally to a symmetric pair, when the full, generalized theory is
applied that interprets also the weak circular polarization Stokes
profile. In most cases a unique solution can be found through additional
information available from disk field polarity.
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Title: Radio and Visible Light Observations of a Coronal Arcade
Transient
Authors: Gergely, T. E.; Kundu, M. R.; Erksine, F. T., III; Sawyer, C.;
Wagner, W. J.; Illing, R.; House, L. L.; McCabe, M. K.; Stewart, R. T.;
Nelson, G. J.; Koomen, M. J.; Michels, D.; Howard, R.; Sheeley, N.
1984SoPh...90..161G Altcode:
We discuss simultaneous visible-light and radio observations of
a coronal transient that occurred on 9 April, 1980. Visible-light
observations of the transient and the associated erupting prominence
were available from the Coronagraph/Polarimeter carried aboard SMM,
the P78-1 coronagraph, and from the Haleakala Observatory. Radio
observations of the related type III-II-IV bursts were available from
the Clark Lake and Culgoora Observatories. The transient was extremely
complex; we suggest that an entire coronal arcade rather than just a
single loop participated in the event. Type III burst sources observed
at the beginning of the event were located along a nearby streamer,
which was not disrupted, but was displaced by the outmoving loops. The
type II burst showed large tangential motion, but unlike such sources
usually do, it had no related herringbone structure. A moving type
IV burst source can be associated with the most dense feature of the
white-light transient.
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Title: A White-Light / Fex / Hα Coronal Transient Observation to
10-SOLAR-RADII
Authors: Wagner, W. J.; Illing, R. M. E.; Sawyer, C. B.; House, L. L.;
Sheeley, N. R., Jr.; Howard, R. A.; Koomen, M. J.; Michels, D. J.;
Smartt, R. N.; Dryer, M.
1983SoPh...83..153W Altcode:
Multi-telescope observations of the coronal transient of 15-16
April, 1980 provide simultaneous data from the Solar Maximum Mission
Coronagraph/Polarimeter, the Solwind Coronagraph, and the new Emission
Line Coronagraph of the Sacramento Peak Observatory. An eruptive
prominence-associated white light transient is for the first time
seen as an unusual wave or brightening in Fe Xgl6374 (but not in
Fe XIVgl5303). Several interpretations of this fleeting enhancement
are offered.
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Title: The association of radio noise storm enhancements with the
appearance of additional material in the corona
Authors: Kerdraon, A.; Pick, M.; Trottet, G.; Sawyer, C.; Illing,
R.; Wagner, W.; House, L.
1983ApJ...265L..19K Altcode:
Visible light observations of the corona have been combined with
radioheliograph observations at metric wavelengths to examine the
dynamic behavior of the corona during and after noise storm onsets and
enhancements. For the period studied, the occurrence of such radio
events is systematically associated with the addition of coronal
material in the vicinity of the radio source. Some of the events
correspond to mass ejection transients, but they more frequently
represent merely a brightening, which grows in 1 hour or less with
the coronal region and remains dense and stable for several hours.
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Title: Solar radio storms. Proceedings of the 4th CESRA workshop on
solar noise storms, held at Trieste, Italy, August 9 - 13, 1982.
Authors: Benz, A. O.; Zlobec, P.; Wentzel, D. G.; House, L. L.; Dulk,
G. A.; Tlamicha, A.; Melrose, D. B.
1983srs..work.....B Altcode:
No abstract at ADS
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Title: Dynamics of the corona 1.5 to 6 solar radii from SMM.
Authors: House, L. L.; Illing, R. M. E.
1983srs..work...99H Altcode:
Observations using the coronagraph/polarimeter on board the Solar
Maximum Mission satellite have found the corona to be a very active
dynamic atmosphere. Significant changes occur in the corona on a
variety of time scales ranging from a few hours to a few days. A
variety of new phenomena have been observed, including the first direct
observations of cool H-alpha material out to 6 R_sun;, impact of a
transient on a pre-existing streamer and wave-like motion of rays and
the outer portions of streamers. The paper stresses the importance of
these observations to interpretation of the source regions of radio
noise storms.
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Title: Visible light observations of a dense plasmoid associated
with a moving Type IV solar radio burst
Authors: Stewart, R. T.; Dulk, G. A.; Sheridan, K. V.; House, L. L.;
Wagner, W. J.; Illing, R.; Sawyer, C.
1982A&A...116..217S Altcode:
A coronal transient rising above the eastern limb of the sun was
observed simultaneously on April 27, 1980 by the Coronagraph/Polarimeter
(C/P) aboard the Solar Maximum Mission spacecraft and by the Culgoora
radioheliograph (CRH). The C/P observed an outward-moving loop
transient followed by a plasmoid of dense ionized material, while the
CRH observed several types of radio bursts, including a moving Type IV
burst at 80 MHz whose position coincided with the bright plasmoid. An
estimate of the reasonable lower limit of the electron density in the
moving Type IV burst indicates that this burst could have resulted
from emission at either the fundamental or the second harmonic of
the plasma frequency. This is a new result because in the past it was
thought that the density in the moving Type IV source region would be
too low for plasma radiation.
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Title: Vector Magnetic Fields in Prominences - Part One - Preliminary
Discussion of Polarimeter Observations in he i D3
Authors: House, L. L.; Smartt, R. N.
1982SoPh...80...53H Altcode:
A preliminary discussion is presented of measurements of the
polarization of the He I D<SUB>3</SUB> multiplet in a quiescent
prominence, observed with a wavelength-scanning Stokes polarimeter. For
a series of 43 observations in the same prominence, the linear
polarization of the major component of D<SUB>3</SUB> lies primarily
in the range 1 to 2% and of the wing component, the range 2 to 5%;
the polarization vector angle lies primarily in the range 10-25°
for the major component, and 25-35° for the other component. From a
more limited data set, the polarization of both components is found
to first increase as a function of height in the prominence, and
then to decrease; the polarization angles of the major component
vary in a random-like way with height, while the wing component
shows a systematic change. The amount of polarization and the angle
of polarization are governed by the Hanle effect. The collective
effect of the group of lines at the peak of D<SUB>3</SUB> evidently
has a different sensitivity to the Hanle effect than does the wing
component, thus yielding at least four independent measurements -
two polarizations and two angles. With some redundancy, the vector
magnetic field can then be established using the detailed theory
of the Hanle effect. Since the wing component of D<SUB>3</SUB> is a
simple triplet, an initial estimate of the magnetic field strength
and its horizontal orientation, 0, relative to the line of sight,
is simply obtained. Examples of such calculations are presented.
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Title: An association between coronal structures and type III
burst sources
Authors: Trottet, G.; Pick, M.; House, L.; Illing, R.; Sawyer, C.;
Wagner, W.
1982A&A...111..306T Altcode:
Observations of the coronal structures overlying type III radio burst
producing regions, obtained with the HAO Coronograph/Polarimeter on
board the Solar Maximum Mission, have been combined with observations
of the type III bursts from the Mark III Nancay Radioheliograph at
169 MHz. A first qualitative comparison of the data, performed for
two periods, indicates that the corona overlying type III producing
sites is composed of small, discrete, over-dense structures, which are
sometimes diverging and short-lived. The type III burst sources are
complex, exhibiting elementary components. It is suggested that the
type III burst structure follows that of the corona and that discrete
structures may play a fundamental role for type III production.
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Title: Coronal emission-line polarization from the statistical
equilibrium of magnetic sublevels. II - Fe XIV 5303 A
Authors: House, L. L.; Querfeld, C. W.; Rees, D. E.
1982ApJ...255..753H Altcode:
Coronal magnetic fields influence the intensity and linear polarization
of light scattered by coronal Fe XIV ions. To interpret polarization
measurements of Fe XIV 5303 A coronal emission requires a detailed
understanding of the dependence of the emitted Stokes vector on
coronal magnetic field direction, electron density, and temperature
and on height of origin. The required dependence is included in the
solutions of statistical equilibrium for the ion which are solved
explicitly for 34 magnetic sublevels in both the ground and four
excited terms. The full solutions are reduced to equivalent simple
analytic forms which clearly show the required dependence on coronal
conditions. The analytic forms of the reduced solutions are suitable
for routine analysis of 5303 green line polarimetric data obtained at
Pic du Midi and from the Solar Maximum Mission Coronagraph/Polarimeter.
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Title: Coronal observations from Solar Maximum Mission satellite.
Authors: Csoeke-Poeckh, A.; Lee, R. H.; Wagner, W. J.; House, L. L.;
Hildner, E.; Sawyer, C.
1982JSpRo..19..345C Altcode:
No abstract at ADS
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Title: Evidence for a shock wave in visible light and radio
observations of the 1980 June 29 event
Authors: Gary, D. E.; Dulk, G. A.; House, L. L.; Wagner, W. J.;
Illing, R. I.; Sawyer, C.; McLean, D. J.
1982AdSpR...2k.253G Altcode: 1982AdSpR...2..253G
Shock waves, as evidenced by type II radio bursts, often accompany
flares and coronal mass ejection transients. At present, the
density enhancements observed by coronagraphs are believed by some
to be ejected matter from the low corona, and by others to be the
compressed material behind a shock front. If the former is correct,
one would expect in some cases to see a density enhancement, associated
with the compression region of the shock, some distance ahead of the
transient ejecta. Such a density enhancement has not been previously
reported. <P />The coronal transient of 1980 June 29 (0233 UT) was
observed with the High Altitude Observatory's Coronagraph/Polarimeter
aboard SMM. This flare-associated coronal transient event was well
observed with the Culgoora Radioheliograph, including a well-developed
type II burst. Visible on the coronagraph images is a faint circular
arc moving out well ahead of the transient loops. This arc is moving
at more than 900 km s<SUP>-1</SUP> while the transient itself is
moving at a speed of about 600 km s<SUP>-1</SUP>. Both the arc and
transient appear to have originated either prior to the X-ray flare
or at some height above the flare at the time of the flare. The type
II burst observed at Culgoora is associated with the transient loops,
and no type II emission is identified with the faint arc. <P />Due to
its great speed, we interpret the faint arc as a manifestation of a
shock wave, but also envision a separate shock wave associated with
the transient loops as evidenced by the type II emission. Preliminary
density measurements are consistent with this interpretation, and show
the outer shock wave associated with the faint arc to have a Mach number
M<SUB>A</SUB> <= 1.7. At present we have no convincing explanation
for the lack of a type II burst in association with the arc. <P />This
work was supported in part by NASA through grants NSG-7287 and NAGW-91
to the University of Colorado, Boulder, and S-55989 to the High Altitude
Observatory, National Center for Atmospheric Research. The National
Center for Atmospheric Research, NCAR, is sponsored by the National
Science Foundation.
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Title: Report of group B - Observational radio/optical phenomena
Authors: House, L. L.; Dulk, G. A.
1982srs..work..332H Altcode:
No abstract at ADS
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Title: Dynamics of the corona 1. 5 and 6 solar radii from SMM (review)
Authors: House, L. L.; Illing, R. M. E.
1982srs..work...99H Altcode:
No abstract at ADS
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Title: Vector Magnetic Fields in Sunspots - Part One - Weak-Line
Observations
Authors: Gurman, J. B.; House, L. L.
1981SoPh...71....5G Altcode:
Observations of a round, unipolar sunspot in the Zeeman triplet Fe I
λ6302.5 with the High Altitude Observatory Stokes Polarimeter are used
to derive the vector magnetic field in the spot. The behavior of the
magnitude, inclination, and azimuth of the field vector B across the
spot is discussed. A linear relation is found between the continuum
intensity I<SUB>c</SUB> and the field magnitude B.
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Title: Hα Ejecta in the Outer Corona
Authors: House, L. L.; Illing, R. M. E.; Sawyer, C.; Wagner, W. J.
1981BAAS...13..862H Altcode:
No abstract at ADS
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Title: The Active Corona II: North Sector. Images from the SMM
Coronagraph/Polarimeter
Authors: Illing, R. M. E.; Wagner, W. J.; House, L. L.; Sawyer, C.
1981BAAS...13..911I Altcode:
No abstract at ADS
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Title: Association of Coronal Transient Phenomena with Disk Flare
Activity from SMM Coronagraph/Polarimeter Data
Authors: Illing, R. M. E.; House, L. L.; Wagner, W. J.; Sawyer, C.
1981BAAS...13..862I Altcode:
No abstract at ADS
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Title: Inhibition of Coronal Transient Loop Formation in Strong
Magnetic Field
Authors: Sawyer, C.; Wagner, W. J.; Illing, R. M. E.; House, L. L.
1981BAAS...13..836S Altcode:
No abstract at ADS
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Title: Radio and visible light observations of matter ejected from
the sun
Authors: Wagner, W. J.; Hildner, E.; House, L. L.; Sawyer, C.;
Sheridan, K. V.; Dulk, G. A.
1981ApJ...244L.123W Altcode:
An initial set of visible light and radio observations of a coronal
transient made with the Coronagraph/Polarimeter experiment on SMM and
the radioheliograph at Culgoora, Australia is presented. It is noted
that an enormous loop-shaped transient observed on April 7, 1980,
exhibited bright material having whiplike, nonradial motions, as well
as moving and stationary radio sources. The data make it possible to
establish that a moving type IV radio source was located on or very
close to the fast-moving loop. The thermal, kinetic, and magnetic
energies in the transient are estimated and, for the first time,
compared with the radiative energy of the associated flare.
---------------------------------------------------------
Title: Studies of the corona with the Solar Maximum Mission
coronagraph/polarimeter
Authors: House, L. L.; Wagner, W. J.; Hildner, E.; Sawyer, C.; Schmidt,
H. U.
1981ApJ...244L.117H Altcode:
The visible wavelength coronagraph/polarimeter on the Solar Maximum
Mission (SMM) spacecraft is providing data on the flare processes
manifested by coronal transients and on the degree of disruption of
the evolutionary corona at the present epoch of the solar activity
cycle. Among the first results are the discovery of frequent H-alpha
emission from remnants of eruptive prominences in the outer corona
and first observations of Fe XIV line emission to 3.2 solar radii. In
the early stages of transients, cavities less dense than the ambient
corona are occasionally found trailing the transient loops, with the
loops being relatively thick and structureless. Some 22 transients
have been identified in the initial survey of 52 days of observations;
from this sample the preliminary conclusion is that transients during
the SMM era (near solar maximum) occur over a wider range of latitude
than, but with about the same range of speeds as, transients during
the Skylab era (near solar minimum).
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Title: Frequency &Location of Coronal Transients Observed w/
the Coronagraph/Polarimeter Aboard SMM Satellite
Authors: Hildner, E.; Illing, R. M. E.; Wagner, W. J.; House, L. L.;
Sawyer, C.; Hyder, C. L.
1981BAAS...13..861H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal observations from the SMM satellite
Authors: Csoeke-Poeckh, A.; Lee, R. H.; Wagner, W. J.; House, L. L.;
Sawyer, C.; Hildner, E.
1981aiaa.meetQ....C Altcode:
The scientific purpose, coronal observations, and the instrument design
and control of the Coronagraph/Polarimeter aboard the Solar Maximum
Mission (SMM) satellite are discussed. The instruments were made with
an optical design using an achromatic objective lens providing a 10
arcsec resolution in imaging and an SEC vidicon detector allowing
integration on the low light levels of the corona. The computer
control assures flexibility in the observing program to optimize
observations of changing solar phenomena and allows rapid response to
SMM or ground-commanded solar flare alerts.
---------------------------------------------------------
Title: Description of a Flare/Eruptive Prominence Associated Coronal
Transient
Authors: Hildner, E.; Sawyer, C. B.; Wagner, W. J.; Illing, R. M. E.;
House, L. L.; Fisher, R. R.; McCabe, M. K.
1980BAAS...12Q.902H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Properties of Hα Ejecta Associated with Coronal Transients
in the Outer Corona
Authors: House, L. L.; Wagner, W. J.; Sawyer, C.; Illing, R. M. E.;
Pneuman, G. W.
1980BAAS...12..900H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Visible Light and Radio Observations of the First Coronal
Transient Event of 1980 June 29
Authors: Gary, D. E.; Dulk, G. A.; Wagner, W.; Sawyer, C.; House,
L.; Stewart, R. T.; McLean, D.
1980BAAS...12..904G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: SMM Coronagraph/Polarimeter Synoptic Observations of the
Active Sun Corona
Authors: Illing, R. M. E.; House, L. L.; Wagner, W. J.; Sawyer, C.
1980BAAS...12..900I Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Relationships Between Type II and Moving Type IV Radio Bursts
and Coronal Visible Light Transients
Authors: Stewart, R. T.; House, L. L.; Wagner, W. J.; Sawyer, C.
1980BAAS...12..898S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Radio and Visible Light Observations of a Coronal Transient
Associated with a Prominence Eruption
Authors: Gergely, T. E.; Kundu, M. R.; Erskine, F. T.; Sawyer, C.;
Wagner, W. J.; Illing, R.; House, L. L.; McCabe, M. K.; Stewart,
R. T.; Nelson, G. J.
1980BAAS...12..900G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Three-Coronagraph Record from 1 to 10 R<SUB>O</SUB> of the
Energetics of a Coronal Transient
Authors: Wagner, W. J.; Sawyer, C.; Illing, R. M. E.; House, L. L.;
Querfeld, C. W.; Sheeley, N. R., Jr.; Howard, R. A.; Koomen, M. J.;
Michels, D. J.; Smartt, R. N.
1980BAAS...12Q.902W Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Asymmetry and nonradiality in coronal transients
Authors: Sawyer, C.; Illing, R. M. E.; House, L. L.; Wagner, W. J.;
Kopp, R.
1980BAAS...12Q.899S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: SMM Coronagraph/Polarimeter Observations of Coronel Transient
Manifestations Correlated with Flare Data
Authors: House, L. L.; Csoeke-Poeckh, A.; Sawyer, C.; Wagner, W. J.;
Hildner, E.
1980BAAS...12Q.535H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Frequency, Locations, Sizes, and Speeds of Coronal Mass
Ejections at the Peak of Solar Cycle 21-Early Results from SMM
Authors: Hildner, E.; House, L. L.; Sawyer, C. B.; Wagner, W. J.
1980BAAS...12R.535H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: SMM Orbiting Coronagraph-Early Results
Authors: Sawyer, C.; Wagner, W. J.; Hildner, E.; House, L. L.
1980BAAS...12Q.531S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Diffuse Density Fronts Moving through the Outer Corona
Observed by the HAO Coronagraph/Polarimeter on the Solar Maximum
Mission Spacecraft
Authors: Wagner, W. J.; Hildner, E.; House, L. L.; Sawyer, C.
1980BAAS...12R.535W Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The High Altitude Observatory coronagraph/polarimeter on the
Solar Maximum Mission.
Authors: MacQueen, R. M.; Csoeke-Poeckh, A.; Hildner, E.; House, L.;
Reynolds, R.; Stanger, A.; Tepoel, H.; Wagner, W.
1980SoPh...65...91M Altcode:
The High Altitude Observatory Coronagraph/Polarimeter, to be flown
on the National Aeronautics and Space Administration's Solar Maximum
Mission satellite, is designed to produce images of the solar corona in
seven wavelength bands in the visible spectral range. The spectral bands
have been chosen to specifically exclude or include `chromospheric'
spectral lines, so as to allow discrimination between ejecta at high
(coronal) and low (chromospheric) temperatures, respectively. In
addition, the instrument features spectral filters designed to permit
an accurate color separation of the F and K coronal components, and a
narrow band (5.5 Å) filter to observe the radiance and polarization
of the Fe XIV 5303 Å line. The effective system resolution is better
than 10 arc sec and the instrument images a selected quadrant (or
smaller field) on an SEC vidicon detector. The total height range
that may be recorded encompasses 1.6 to more than 6.0R<SUB>⊙</SUB>
(from Sun center). The instrument is pointed independently of the
SMM spacecraft, and its functions are controlled through the use
of a program resident within the onboard spacecraft computer. Major
experimental goals include: (a) Observation of the role of the corona
in the flare process and of the ejecta from the flare site and the
overlying corona; (b) the study of the direction of magnetic fields in
stable coronal forms, and, perhaps, ejecta; and (c) examination of the
evolution of the solar corona near the period of solar maximum activity.
---------------------------------------------------------
Title: A spectrum scanning Stokes polarimeter.
Authors: Baur, T. G.; House, L. L.; Hull, H. K.
1980SoPh...65..111B Altcode:
A photoelectric polarimeter for measuring line profiles in all
four Stokes parameters has been built and operates on the SPO 40 cm
coronagraph in a joint project with Sacramento Peak Observatory. A
description of the optical and electronic systems and the calibration
scheme is presented. Performance parameters determined from observations
are also given. The polarimeter package consisting of a pair of KDP's,
a quarter wave plate, and a polarizing beam splitter is located at
the prime focus of the coronagraph. Modulation of the KDP's encodes
polarization information into intensity signals that are electronically
detected. The scanning of the spectrum, accomplished by rotating the
grating, permits Stokes line profiles to be recorded on magnetic tape
for processing. The instrument can be used to scan any line from 3900
to 7000 Å with a spectral resolution of 0.01 Å. Polarizations as
small as 0.001% are detectable. The polarimeter and observing system
are computer controlled.
---------------------------------------------------------
Title: Polarization Measurements of Prominences - Characteristics
of Stokes Profiles
Authors: Smartt, R. N.; House, L. L.
1979BAAS...11..409S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Stokes Polarimetry of Quiescent Prominences in HeI
D<SUB>3</SUB>.
Authors: House, L. L.; Smartt, R. N.
1979phsp.coll...81H Altcode: 1979IAUCo..44...81H; 1979phsp.conf...81H
No abstract at ADS
---------------------------------------------------------
Title: Stokes Polarimetry of Quiescent Prominences in He I
D<SUB>3</SUB>
Authors: House, L. L.; Smartt, R. N.
1978BAAS...10..672H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Radiative transfer calculated from a Markov chain formalism.
Authors: Esposito, L. W.; House, L. L.
1978ApJ...219.1058E Altcode:
The theory of Markov chains is used to formulate the radiative transport
problem in a general way by modeling the successive interactions
of a photon as a stochastic process. Under the minimal requirement
that the stochastic process is a Markov chain, the determination of
the diffuse reflection or transmission from a scattering atmosphere
is equivalent to the solution of a system of linear equations. This
treatment is mathematically equivalent to, and thus has many of the
advantages of, Monte Carlo methods, but can be considerably more
rapid than Monte Carlo algorithms for numerical calculations in
particular applications. We have verified the speed and accuracy of
this formalism for the standard problem of finding the intensity of
scattered light from a homogeneous plane-parallel atmosphere with an
arbitrary phase function for scattering. Accurate results over a wide
range of parameters were obtained with computation times comparable
to those of a standard 'doubling' routine. The generality of this
formalism thus allows fast, direct solutions to problems that were
previously soluble only by Monte Carlo methods. Some comparisons are
made with respect to integral equation methods.
---------------------------------------------------------
Title: The determination of vector magnetic fields from Stokes
profiles.
Authors: Auer, L. H.; Heasley, J. N.; House, L. L.
1977SoPh...55...47A Altcode:
The application of Unno's (1956) solution of the transfer equation
for polarized radiation to the determination of thevector magnetic
field is investigated. An analysis procedure utilizing non-linear
least squares techniques is developed that allows one to automate the
reduction of measured spectral profiles of the Stokes parameters to
determine the field angles, strength as well as other parameters. The
method is applied to synthetic spectra generated using a model solar
atmosphere and yields results of remarkably high accuracy. The influence
of additional factors upon determination of the vector field are also
considered. These factors include effects of asymmetric profiles,
magneto-optical effects, magnetic field gradients, unresolved field
elements, scattered light, and instrumental noise.
---------------------------------------------------------
Title: Non-LTE line formation in the presence of magnetic fields.
Authors: Auer, L. H.; Heasley, J. N.; House, L. L.
1977ApJ...216..531A Altcode:
The equations of radiative transfer and statistical equilibrium in
the presence of a magnetic field are presented. A general difference
equation scheme for solving the vector transfer equation in Stokes
parameters, allowing for arbitrary variations of the magnetic field
and other quantities, is described. The solution of the Stokes non-LTE
problem for Ca II by the complete linearization method is described,
and numerical examples of the procedure are presented.
---------------------------------------------------------
Title: Radiative Transfer Calculated from a Markov Chain Formalism
Authors: Esposito, L. W.; House, L.
1977BAAS....9R.470E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal emission-line polarization from the statistical
equilibrium of magnetic sublevels. I. Fe XIII.
Authors: House, L. L.
1977ApJ...214..632H Altcode:
A general formulation for the polarization of coronal emission lines
is presented, and the physics is illustrated through application
of the formulation to the lines of Fe xiii at 10747 and 10798
A. The goal is to present a foundation for the determination of the
orientation of coronal magnetic fields from emission-line polarization
measurements. The physics of emission-line polarization is discussed
using the statistical equilibrium equations for the magnetic
sublevels of a coronal ion. The formulation of these equations,
which describe the polarization of the radiation field in terms of
Stokes parameters, is presented; and the various rate parameters-
both radiative and collisional-are considered. The emission Stokes
vector is constructed from the solution of the equilibrium equations
for a point in the corona where the magnetic field has an arbitrary
orientation. From these results, it is possible to discuss the
development of a full three-dimensional model for emission-line
polarization from the corona in which the temperature, density, and
magnetic field structure may have arbitrary distributions. Integration
along the line of sight is accounted for. On the basis of this model,
a computer code for the calculation of emission-line polarization is
briefly described and illustrated with a number of sample calculations
for Fe xiii. Calculations are carried out for three-dimensional
models that demonstrate the physics of the formation of emission-line
polarization and illustrate how the degree of polarization and angle
of polarization and their variations over the corona are related to
the density and magnetic field structure. The models considered range
from simple cases in which the density distribution with height is
spherically symmetric and the field is radial or dipole to a complex
case in which both the density and magnetic field distributions are
derived from realistic three-dimensional distributions for the 1973
eclipse on the basis of K-coronameter measurements for the density
and potential-field extrapolation of surface magnetic fields in the
corona. Subject headings: atomic processes - polarization - Sun:
corona - Sun: magnetic fields - Zeeman effect
---------------------------------------------------------
Title: A spectrum scanning Stokes polarimeter
Authors: Baur, T. G.; House, L. L.
1977SPIE..112..209B Altcode:
A photoelectric polarimeter for measuring solar spectral line profiles
in all four Stokes parameters has been built and operates on a 40 cm
coronagraph in a joint project with Sacramento Peak Observatory. A
description of the optical and electronic systems and the calibration
scheme is presented. Performance parameters determined from observations
are also given. The polarimeter package consisting of a pair of KDP's,
a quarter wave plate, and a polarizing beam splitter is located at
the prime focus of the coronograph. Modulation of the KDP's encodes
polarization information into intensity signals that are electronically
detected. The scanning of the spectrum, accomplished by rotating the
grating, permits Stokes line profiles to be recorded on magnetic tape
for processing. The instrument can be used to scan any line from 3900
to 7000 A with a spectral resolution of .01 A. Polarizations as small
as .001 percent are detectable. The polarimeter and observing system
are computer controlled.
---------------------------------------------------------
Title: A spectral scanning Stokes polarimeter.
Authors: Baur, T. G.; House, L. L.
1977oppo.conf..209B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Confirmation of Strong Small Scale Fields in the Solar
Photosphere.
Authors: House, L. L.; Baur, T. G.; Elmore, D. E.
1976BAAS....8Q.500H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Observation of Vector Magnetic Fields in Sunspots
Authors: House, L. L.; Baur, T. G.; Elmore, D. E.; Auer, L. W.;
Gurman, J.; Heasley, J. N.
1976BAAS....8..346H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Division of Solar Physics: 1975. Annual report.
Authors: House, L. L.
1976BAAS....8..401H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Initial Operation of a Scanning Stokes Polarimeter
Authors: House, L. L.; Baur, T. G.; Hull, H. K.
1975SoPh...45..495H Altcode: 1976SoPh...45..495H
A polarimeter capable of obtaining line profiles in the four Stokes
parameters is described in its initial operation. A brief description
of the instrument and the first sunspot observation is given.
---------------------------------------------------------
Title: Initial Results from a Scanning Stokes Polarimeter
Authors: House, L. L.; Baur, T. G.; Hull, H. K.
1975BAAS....7..349H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Non-LTE Line Formation in the Presence of a Magnetic Field
Authors: Auer, L. H.; Heasley, J. N.; House, L. L.
1975BAAS....7..349A Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Spectrum Scanning Stokes Polarimeter
Authors: Baur, T. G.; House, L. L.; Hull, H. K.
1975BAAS....7..351B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The non-LTE transport equation for polarized radiation in
the presence of magnetic fields. I. Formulation.
Authors: House, L. L.; Steinitz, R.
1975ApJ...195..235H Altcode:
A formulation of the radiative transfer of polarized light under
conditions departing from local thermodynamic equilibrium and accounting
for the presence of a magnetic field is presented. The formulation is
self-consistent in that the equations of statistical equilibrium for
magnetic sublevels are also included. The quantum-mechanical derivation
of the absorption matrix, the key to the presentation, is derived in
detail utilizing the density matrix approach. The polarization of the
radiation field is described in terms of the usual Stokes parameters,
but the discussion of the Stokes parameters in this paper illustrates
their quantum mechanical origin and interpretation. The equation of
radiative transfer for the Stokes vector is cast in a form reminiscent
of the nonlocal thermodynamic equilibrium (NLTE) scalar equation
of transfer, except that the equation is now a vector equation in
the Stokes parameters and the source function is a vector function
containing the population of magnetic sublevels.
---------------------------------------------------------
Title: The Theory of the Polarization of Coronal Forbidden Lines
Authors: House, Lewis L.
1974PASP...86..490H Altcode:
A brief review, presented in simplified terms, is given for the
theory of the origin of coronal emission-line polarization. A
classical view of the scattering problem in terms of harmonic
oscillators is first presented where the influence of the magnetic
field is demonstrated. The Van Vleck depolarization phenomena is
described in these terms. Next, a more precise physical picture of
the emission-line polarization is established through a discussion
of the Zeeman effect in scattering. Sample results are discussed for
three-dimensional coronal emission4ine models based upon the solution
of the statistical equilibrium equations for magnetic sublevels of the
Fe xiv ion. Finally, comments are directed toward the determination
of magnetic fields based upon emission-line polarization observations
where both medeling and deconvolution procedures are mentioned. Key
words: corona - polarization - magnetic fields - forbidden lines
---------------------------------------------------------
Title: The Stokes Formulation of Non-LTE Radiative Transfer in a
Magnetic Field
Authors: House, Lewis L.; Steinitz, Raphael
1973ApL....15..129H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal Emission Line Polarization
Authors: House, Lewis L.
1972SoPh...23..103H Altcode:
A discussion of a program for the computation of coronal emission line
polarization is presented. The starting point is a general formulation
of the scattering function for magnetic dipole transitions between any
two total angular momentum levels, J → J, J ± 1. Illustration of
the behavior of the scattering function for different transitions is
given. The integration of the scattering function over the solar disk
and along the line of sight accounting for arbitrary distribution of
magnetic fields as well as an inhomogeneous temperature and density
structure of the corona is considered next.
---------------------------------------------------------
Title: The Mueller Matrix for Scattering - Including the Effects
of Interference
Authors: House, L. L.
1972lfpm.conf...71H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Coronal Emission Line Polarization
Authors: House, L. L.
1972lfpm.conf..113H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Empirically Corrected Calculations of Coronal Visible Lines
from the 3p^{5}3D Configuration
Authors: Wagner, William J.; House, Lewis L.
1971ApJ...166..683W Altcode:
A laboratory study of extreme-ultraviolet spectral lines provided
empirical data on the 3p23d configuration in high ionization stages of
the Ar I sequence. Using a three-electrode spark source with variable
inductance, we have identified t elve 3p53d-3p84f transitions in each of
the ions V vi to Fe ix. A least-squares procedure gave a fit of Slater
integrals, spin-orbit parameters, and interactions of the type aL(L +
1) to the extreme-ultraviolet wavelengths. Using these empirically
corrected energy parameters, we recalculated the energy levels of the
3p03d configuration. Within 3p53d, we suggest that six magnetic-dipole
transitions may be associated with visible emission lines observed in
the solar corona: N3021, Ni xi, 3F3-1D1 X3167, Fe ix, 3F3-0F3; X3534,
Fe ix, 3F2-3D2 X3643, Fe ix, 3F3-'D3; 3S01, Ni xi, 3F3-1D2 4359,
Fe ix, 3F3-3D2.
---------------------------------------------------------
Title: Solar Superthermal Event Deduced from X-Ray Lines
Authors: Blake, Richard L.; House, Lewis L.
1971ApJ...166..423B Altcode:
improved identifications are given for the ionization stages of iron
that contributed to the 1.91 A emission feature in solar spectra
obtained by the NRL group in a 1966 rocket flight. in addition, it is
shown that the observed emission requires a two-component model of the
coronal condensation in which, over some 100 seconds, one component
must have either departures from iaxwellian velocity distributions or
differences in ionization and electron temperatures.
---------------------------------------------------------
Title: Coherence Properties of Polarized Radiation in Weak Magnetic
Fields
Authors: House, L. L.
1971IAUS...43..130H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The resonance fluorescence of polarized radiation - III. The
Stokes parameter and circular polarization formulation of the
scattering redistribution function.
Authors: House, L. L.
1971JQSRT..11..367H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Empirically-corrected calculations of coronal visible lines
from the 3p<SUP>5</SUP>3d configuration.
Authors: Wagner, W. J.; House, L. L.
1971BAAS....3T.265W Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The resonance fluorescence of polarized radiation - I. The
general scattering function.
Authors: House, L. L.
1970JQSRT..10..909H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The resonance fluorescence of polarized radiation-
II. Scattering in the normal Zeeman triplet (J = 0 - J” = 1).
Authors: House, L. L.
1970JQSRT..10.1171H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Solar Spicule Model Based Upon Calcium II K Line Radiative
Transfer Studies
Authors: Avery, Lorne W.; House, Lewis L.
1969SoPh...10...88A Altcode:
Monte Carlo radiative transfer techniques are used to develop a
height-dependent spicule model based upon a more realistic configuration
than has hitherto been considered. The spicule is represented by a
uniform cylinder, of finite length, standing vertically upon a plane
chromosphere. The observed, limb-darkened, anisotropic chromospheric
flux incident upon the cylinder is incorporated into the transfer
calculations.
---------------------------------------------------------
Title: The Treatment of Resonance Scattering of Polarized Radiation
in Weak Magnetic Fields by the Monte Carlo Technique
Authors: House, Lewis L.; Cohen, Leonard C.
1969ApJ...157..261H Altcode:
The problem of resonance scattering in a finite medium which is
permeated by a uniform magnetic field is described. A parallel beam of
unpolarized photons is assumed incident upon the lower surface of the
scattering medium, the direction of propagation being perpendicular
to the magnetic field Through inclusion of the Hanle effect which
influences the phase coherency of the scattering process, it has
been possible to treat the case of weak fields for the normal Zeeman
triplet. This is in contrast to most studies of the transport of
polarized radiation in which a strong field is assumed, giving rise to
well-separated Zeeman components. By the Monte Carlo process "photons"
are traced through the scattering medium by using the prob- abilistic
laws of interaction, and, by counting the "photons" as they exit,
line profiles and the degree of polarization are determined. Results
are given for viewing the medium both along and perpendicular to the
magnetic field. When the medium is optically thin and viewed along
the magnetic field, the linear polarization may change from 100 toO
per cent because of the Hanle effect. As the optical depth increases,
additional depolarization occurs because of multiple scattering,
and it is found that an average of oniy five to ten scatterings are
required to completely depolarize the radiation essentially independent
of the magnetic field strength. Future application of this type of
calculation is discussed in relation to quiescent prominences in the
solar atmosphere
---------------------------------------------------------
Title: Hartree-Fock Calculations of Coronal Forbidden Lines in the
Argon i Iso-Electronic Sequence
Authors: Wagner, William J.; House, Lewis L.
1969ApJ...155..677W Altcode:
In the Argon i isoelectronic sequence it is highly likely that coronal
forbidden visible transitions will be discovered occurring between
levels of the lowest excited configuration 3p53d. Hartree-Fock calcula-
tions of wavelengths and magnetic dipole and electric quadrupole
transition probabilities have been made in the ions Cr vii to Cu xii. In
these stages thirty-four forbidden lines are predicted having transition
probabilities greater than 1 sec'. Due to large uncertainties inherent
in state-of-the-art self-consistent field calculations, the predicted
wavelengths have insufficient accuracy at present to allow a unique
identification with coronal lines observed at eclipses
---------------------------------------------------------
Title: Theoretical Wavelengths for Ka-TYPE X-Ray Lines in the Spectra
of Ionized Atoms (carbon to Copper)
Authors: House, Lewis L.
1969ApJS...18...21H Altcode:
Theoretical Hartree-Fock calculations have been used to determine
wavelengths of Ka-type X-ray transitions in atoms in which a varying
number of the outer, shielding electrons have been removed. The atoms
treated range from carbon to copper, and for each element all stages
of ionization are considered, with the exception, where applicable,
of those stages containing electrons beyond the 3d shell. For the
light elements, carbon to neon, the influence of term structure is
taken into account. In addition to wavelengths, tables are given
for configuratioa and term energies, dipole integrals, and relative
multiplet strengths. Comparison of the theoretical wavelengths with
known normal Ka X-ray lines and with observed or extrapolated lines
in helium-like ions shows that the calculations are not in error by
more than 5 per cent. An adjustment of the calculations to match the
few known wavelengths yields final results that can aid in further
laboratory and astronomical studies of the identification of these
unusual X-ray lines.
---------------------------------------------------------
Title: Radiative transport in finite homogeneous cylinders by the
Monte Carlo technique.
Authors: Avery, L. W.; House, L. L.; Skumanich, A.
1969JQSRT...9..519A Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Monte Carlo technique applied to radiative transfer.
Authors: House, L. L.; Avery, L. W.
1969JQSRT...9.1579H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Reinterpretation of the Feature at 23.28 Å in Solar Soft-X
Spectra
Authors: Blake, Richard L.; House, Lewis L.
1968ApJ...154L.141B Altcode:
The feature at 23.28 A observed in solar X-ray spectra and previously
reported (Blake and House) as probably a Ka-type line of 0 iii is
actually an instrumental effect. Other lines, particularly X1.91,
suggested by Fritz et a!., are still believed to be Ka-type lines
---------------------------------------------------------
Title: The Monte Carlo Technique Applied to Radiative Transfer
Authors: House, L. L.; Avery, L. W.
1968rla..conf..133H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Treatment of Resonance Scattering of Polarized Radiation
in Weak Magnetic Fields by the Monte Carlo Technique
Authors: House, L. L.; Cohen, L. C.
1968rla..conf..255H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Survey of Current Coronal Visible Line Identifications
Authors: Wagner, William J.; House, Lewis L.
1968SoPh....5...55W Altcode:
A literature search has been made pertaining to the identifications
of coronal visible lines. Of over one hundred lines reported seen
at eclipses, about forty identifications are widely quoted. Close
scrutiny of the literature, however, reveals that only twenty of these
identifications are not disputed by one or more authors.
---------------------------------------------------------
Title: An Investigation of Resonance-Line Scattering by the Monte
Carlo Technique
Authors: Avery, Lorne W.; House, Lewis L.
1968ApJ...152..493A Altcode:
The problem of photon diffusion through a purely scattering atmosphere
is investigated by means of the Monte Carlo technique for two types of
scattering: (1) complete redistribution and (2) coherent scattering
in the rest frame of the atom which leads to partially coherent
scattering in the external frame. The Monte Carlo techniques are
applied to Lyman-a photons generated at a point source at the center
of a plane-parallel slab of large optical thickness. The mean number
of scatterings required for escape, (N), is computed for both types
of scattering. For thick slabs (N) is found to be much greater under
partially coherent conditions. As a result the source function should
approach the equilibrium value at smaller optical depths than one
predicts under complete redistribution. In addition it is found that,
under partially coherent scattering, photons tend to diffuse more
easily in space, but less easily in frequency than under complete
redistribution. Thus for complete redistribution the photons are more
likely to remain in the vicinity of their origin until they escape
from the atmosphere as the result of a single, large frequency shift
---------------------------------------------------------
Title: Radiation Transport in a Medium with a Magnetic Field.
Authors: House, Lewis L.
1968AJS....73S..63H Altcode:
The Monte Carlo method has been applied to photon transport in volume
simulating quiescent prominence. This volume is taken to be finite
in two dimensions, homogeneous, and permeated by a uniform magnetic
field. The lower surface of the model prominence is illuminated by a
continuum of unpolarized photons which are assumed to undergo pure
scattering. There is no thermal generation of photons within the
atmosphere for the present model. The model atom assumed produces a
normal Zeeman triplet. In this particular case, application can be
made to the resonance line 4227A of Cai. By the Monte Carlo method
the history of the photon states of polarization ~1,j2, and ir are
traced through the multiple scattering process, and emergent line
profiles in flux and intensity are constructed. The absorption line
as seen looking at the top and the emission lines from the side and
bottom of the prominence will be discussed showing the relation between
broadening, polarization, and total intensity or flux versus magnetic
field, density and dimensions of the prominence.
---------------------------------------------------------
Title: Additional Resonance Lines of Highly Ionized Sulfur, Chlorine,
Argon, and Potassium
Authors: Deutschman, William A.; House, Lewis L.
1967ApJ...149..451D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Some Intermediate Coupling Transition Probabilities in Ca XV
and Fe XIII
Authors: House, Lewis L.
1967ApJ...149..211H Altcode:
Absolute line strengths and transition probabilities are calculated in
the domain of intermediate coupling for the transition array s2p2-sp3
in Ca xv and Fe xiii. The dipole integrals as well as the energy
parameters are calculated from the Hartree-Fock program of Dr. Charlotte
Froese. Extrapolated wavelengths are given where sufficient empirical
data are available; otherwise, theoretical Hartree-Fock energies are
used to compute the wavelengths. The results clearly indicate the
necessity for the use of intermediate coupling results where coronal
statistical equilibrium problems are concerned. Several lines forbidden
in LS coupling show strengths comparable to allowed resonance lines and
should, therefore, be observable in the extreme ultraviolet spectrum
of the solar corona.
---------------------------------------------------------
Title: K-α X-Ray Transitions in the Solar Atmosphere and Laboratory
Plasma
Authors: Blake, R. L.; House, L. L.
1967ApJ...149L..33B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Erratum: New Inner-Shell Resonance Lines in Highly Ionized
Sulfur and Chlorine
Authors: Deutschman, William A.; House, Lewis L.
1966ApJ...145..660D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: New Inner-Shell Resonance Lines in Highly Ionized Sulfur
and Chlorine
Authors: Deutschman, William A.; House, Lewis L.
1966ApJ...144..435D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Erratum: the Formation of the Lyman Continuum: Isothermal
Atmosphere.
Authors: Dietz, R. D.; House, L. L.
1965ApJ...142.1315D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Formation of the Lyman Continuum: Isothermal Atmosphere.
Authors: Dietz, R. D.; House, L. L.
1965ApJ...141.1393D Altcode:
We present in this paper some techniques and results which form a basis
for analysis of the solar Lyman continuum The source function for an
atom with one bound level is derived taking into account the frequency
dependence of continuum processes The Eddington transfer equation
for Lyman-continuum radiation in an isothermal, constant-density,
hydrogen atmosphere is solved numerically. An approximate analytic
solution of the problem is also obtained.
---------------------------------------------------------
Title: Laboratory production of the solar iron lines in the vacuum
ultra-violet
Authors: House, L. L.
1965IAUS...23...27H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Time-Dependent Coronal Ionization.
Authors: House, L. L.; Billings, D. E.
1964ApJ...140.1182H Altcode:
Time-dependent ionization processes are tested for possible
significance under the conditions of a shodk wave passing through
the corona. Equations are solved to determine the time variation of
ion and electron temperatures. The resulting electron temperature is
used to compute the time variation in ionization of iron. The results
of these calculations, when compared to observational characteristics
of the corona, definitely favor processes in the corona comparable in
scale and frequency to those in the photosphere.
---------------------------------------------------------
Title: The laboratory production of solar iron lines in the vacuum
ultraviolet
Authors: House, Lewis L.
1964AnAp...27..763H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Neon VII and VIII Wavelengths in the Vacuum Ultraviolet.
Authors: House, Lewis L.; Sawyer, George A.
1964ApJ...139..775H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Ionization Equilibrium of the Elements from H to Fe.
Authors: House, Lewis L.
1964ApJS....8..307H Altcode:
Non-thermodynamic equilibrium calculations to determine the relative
concentration of the various stages of ionization of the elements
from H to Fe are presented. The results are derived from statistical
equilibrium equations for simplified atomic models containing only a
ground state and continuum for each stage of ionization. Calculations
are given for an electron temperature range of logio T(ev) = -0.5 to
3.0. In general, the calculations apply for an electron density n, <
10 . In many cases they are valid for high densities, n, = 1016 or 10
. A table is given which allows one to determine the upper-limIt of
n, for any specific case. The same table illustrates the value of n,
required before local thermodynamic equilibrium would be valid.
---------------------------------------------------------
Title: Excitation of Chromospheric MG I.
Authors: Athay, R. Grant; House, L. L.
1963ApJ...137..601A Altcode:
Our earlier analysis of chromospheric Mg I data is extended to
discussions of both empirical and theoretical departures from radiative
detailed balance in the strong singlet and triplet lines. At 500 km,
general agreement between the empirical and theoretical values is
obtained for all lines, assuming an isothermal, spherically symmetric
atmosphere. At heights of 1000 and 1500 km, however, further evidence
is found for strong departures from spherical symmetry.
---------------------------------------------------------
Title: Departures from Thermodynamic Equilibrium in Chromospheric
MG i, CA i, and O I.
Authors: Athay, R. Grant; House, Lewis L.
1962ApJ...135..500A Altcode:
Comparisons of intensities of Mg I and 0 I emission lines in the
flash-spectrum of the low chromosphere reveal evidence of marked
departures from a Boltzmann distribution of populations of energy
levels. These departures are in the same sense as those found earlier
for He I, viz , an overpopulation of the levels connected to the
ground state through optically forbidden transitions relative to the
levels with permitted transitions. A search for a similar effect in
the populations of the excited singlets and triplets of Ca I has not
indicated a significant departure from a Boltzmann distribution for the
levels studied. However, evidence is found that the ratio Ca i/Ca ii is
much greater than would be expected in thermodynamic equilibrium. In
the case of Mg I, the optical thickness of the chromosphere in the
triplet lines is obtained directly from the observed intensity of the
forbidden intercombination line X 4571 (33P-31S). Computed populations
of energy levels for a model Mg I atom under a range of temperature
and density show satisfactory agreement with observational data for
choices of chromospheric temperatures and densities consistent with
a model departing from spherical symmetry given by Thomas and Athay
(1961, chap. 7).
---------------------------------------------------------
Title: Departures from Thermodynamic Equilibrium in Chromospheric
Magnesium i, Calcium i, and Oxygen I.
Authors: House, Lewis Lundberg
1962PhDT.........1H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Balmer: Paschen Ratio in the Chromosphere and the
Equilibrium Populations of Hydrogen Angular-Momentum States.
Authors: House, Lewis L.; Athay, R. Grant; Zirin, Harold
1961ApJ...133..608H Altcode:
The work reported in this paper is a test of the hypothesis that the
angular-momentum states of hydrogen are not populated according to
their statistical weights. The anomalous ratio of the hydrogen Balmer to
Paschen lines observed at the 1952 eclipse is investigated in relation
to both observations and theoretical calculations. The Paschen decrement
is used to test for a reduced population of states of higher angular
momentum; such a depopulation of states was previously suggested as
accounting for the anomalous ratio. The decrement does not confirm the
suggestion. A statistical equilibrium analysis of the angular-momentum
states is used to determine departures in the populations from their
LTE values. The results indicate that departures are too small to
give the observed Balmer: Paschen ratio. An calculation shows that it
is reasonable to average together the substates of different angular
momentum in hydrogen chromospheric calculations.
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Title: Departures from Thermodynamic Equilibrium in Chromospheric MgI,
CaI, and OI.
Authors: House, Lewis L.; Athay, R. Grant
1961AJ.....66U.286H Altcode:
Line intensities from the chromospheric flash spectrum observed at
the 1952 total eclipse clearly indicate marked departures from LTE in
Mgi and Oi. The same is suggested for Cai, but not unambiguously. The
following remarks relate only to Mgi. The stronger triplets X5184 and
X3838 are influenced by self-absorption for heights below about 2500
km. The forbidden line X4571 is observed, and is shown to be free from
self-absorption. Its intensity leads directly to the opacities in the X5
184 and X3838 triplets. At 500 km the radial opacities at line center
are T5i94 3 and T3539 7, establishing that the centers of these lines
in the Fraunhofer spectrum are chromospheric in origin. The singlet
line X5528 is observed to fall off much more rapidly with height than
the triplets even in the absence of self-absorption. The singlet to
triplet ratios give unambiguous evidence of departures from LTE. At
1000 km, the intensity of X4571 is enhanced relative to X5528 by
factors of 20 to 200 for assumed values of Te of 60000 and 10 0000,
respectively. Solutions to the statistical equilibrium equations yield
populations of energy levels in good agreement with the empirical
values for opacities consistent with those in the chromosphere. The
departures from LTE in 3'S and 33P are shown to be the same and
essentially independent of height. Typical computed values are b3'5~25
at 60000 and 200 at 80000. The departures from LTE in the higher triplet
levels are also relatively independent of height. Typical values are
b435~1.4 at 60000 and 3.3 at 80000. For the upper level of N5528, 4'd,
the departure from LTE depends strongly on height thereby accounting
for the steep gradient in the X5528 emission.
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Title: Oscillator Strength for the 3s3p^{2} ^{2}S-3s^{2} 3p^{2}P
Transition in AL I.
Authors: Eddy, John A.; House, Lewis L.; Zirin, Harold
1961ApJ...133..299E Altcode:
The oscillator strength for the transition 1s22s22p63s23p2 P2i2, 2S1/2
of Al I has been calculated. A potential was obtained which allowed a
numerical solution of the equation for the ground- and excited-state
wave functions. An f-value of 034 was computed from both the dipole
and the momentum matrix elements, using theoretical energy levels
This is thought to be a more reliable value than that derived from
observed energies.
