explanation blue bibcodes open ADS page with paths to full text
Author name code: edmonds
ADS astronomy entries on 2022-09-14
author:"Edmonds, Frank N."
---------------------------------------------------------
Title: A Statistical Analysis of NAID1 Profile Fluctuations at the
Center of the Solar Disk - Part One - Data Reduction and Resolvable
Velocities
Authors: Edmonds, F. N., Jr.; Hsu, J. -C.
1983SoPh...83..217E Altcode:
Three radial-velocity fluctuation arrays V(Δλ, Y) and line-formation
fluctuation arrays L(Δλ, Y),where Δλ is wavelength displacement
from the center of NaI D<SUB>1</SUB> and Y is displacement on the Sun's
surface along the spectrograph slit, were obtained from Sacramento
Peak Observatory spectrograms. The variations of these line profile
fluctuations are qualitatively described. The RMS<SUB>υ</SUB>'s,
coherences, and power spectra shapes for V(Δλ, Y) fluctuations are
examined at different Δλ with the corresponding effective heights
of formation calculated with Mein weighting functions.
---------------------------------------------------------
Title: A statistical analysis of resolvable velocities obtained from
solar Na I D<SUB>1</SUB> profile fluctuations.
Authors: Edmonds, F. N., Jr.; Hsu, J. -C.
1983BAAS...15..615E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A feasibility study of calibrating stellar photographic
equivalent widths against solar photoelectric equivalent widths.
Authors: Edmonds, F. N., Jr.
1978PASP...90..322E Altcode:
The feasibility of reducing average systematic-plus-random errors in
stellar photographic equivalent widths to S 5% by a direct calibration
method is examined. Solar and stellar 2.5 A mm ' spectrograms covering
the same wavelength range are exposed, developed, and reduced as
similarly as possible, and the calibration of the solar equivalent
widths against those obtained from A High-Resolution Spectral
Atlas of the Solar Irradiance from 380 to 770 Nanometers is used
to correct the stellar equivalent widths for systematic errors. The
effects on overall accuracy of the procedure due to collimator (slit)
illumination, development uniformity, density-to-intensity calibration,
fixing continuum, width of profile measured, and filtering of noise are
investigated. Overall procedure accuracy is estimated by comparison
of calibrated (i.e., corrected) equivalent widths for Arcturus with
those obtained from A Photometric Atlas of the Spectrum of Arcturus,
and from reticon spectra taken at McDonald Observatory. The 5% average
accuracy upper limit is feasible. The study also produces several
cautions and recommended improvements for the procedure. Its potential
for standardizing stellar equivalent widths is briefly discussed. Key
words: equivalent widths-photographic spectra
---------------------------------------------------------
Title: A Feasibility Study of Calibrating Stellar Photographic
Equivalent Widths against solar Photoelectric Equivalent Widths.
Authors: Edmonds, F. N., Jr.
1977BAAS....9..635E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spectral analyses of solar photospheric fluctuations. V:
A two-dimensional analysis of granulation at the center of the disk.
Authors: Edmonds, F. N., Jr.; Hinkle, K. H.
1977SoPh...51..273E Altcode:
Successful subtraction of instrumental background variations has
permitted spectral analyses of two-dimensional measurement arrays of
granulation brightness fluctuations at the center of the disk, arrays
obtained from Stratoscope I, 1959B-flight, high-resolution frames B1551
and B3241. RMS's, uncorrected for instrumental blurring, are 0.0850 of
mean intensity for B1551 and 0.0736 for B3241, somewhat higher than
other determinations. These between-frame and between-investigation
differences probably result from a combination of calibration errors,
frame resolution differences, and, most likely, granulation pattern
differences.
---------------------------------------------------------
Title: A Two-Dimensional Spectral Analysis of Solar Granulation at
the Center of the Disk
Authors: Edmonds, F. N., Jr.; Hinkle, K. H.
1976BAAS....8..311E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spectral Analyses of Solar Photospheric Eluctuations. IV:
The Low-Wavenumber Power of Granulation Brightness Eluctuations
Authors: Edmonds, F. N., Jr.
1975SoPh...44..293E Altcode:
Synthetic one-dimensional scans of brightness fluctuations are generated
from intergranulegranule profiles (IGP), which approximate observed
scans of granulation fluctuations except that the local (i.e. IGP)
mean intensity is kept constant. Comparing the power spectrum of such
scans with the power spectrum of observed scans shows that nearly
two thirds of the low-wavenumber (k < 0.0025 km<SUP>-1</SUP>)
granulation power is due to this variable mean effect. This result
favors the interpretation of granulation as turbulent thermal convection
but cannot rule out the laminar convection interpretation.
---------------------------------------------------------
Title: Convective Flux in the Solar Photosphere as Determined from
Fluctuations
Authors: Edmonds, F. N., Jr.
1975BAAS....7..362E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Convective Flux in the Solar Photosphere as Determined from
Fluctuations
Authors: Edmonds, F. N., Jr.
1974SoPh...38...33E Altcode:
The fractional convective flux πF<SUB>c</SUB>(x<SUB>c</SUB>/πF)
is computed for the effective level x<SUB>c</SUB>= logτ<SUB>c</SUB> =
0.125, using bi-dimensional co-spectra for relative continuum-brightness
fluctuations ΔI and radial velocity fluctuations ΔV measured for
the C<SUB>I</SUB> 5052.16 spectral line. A more uncertain flux for
x<SUB>Fe</SUB> ≈ - 0.9 is obtained for the Fe<SUB>I</SUB> 5049.83
line. Since the results (Figure 1) incorporate current uncertainties
in RMS<SUB>ΔI</SUB>, RMS<SUB>ΔV</SUB> and RMS<SUB>ΔT</SUB>(x),
where ΔT are photospheric temperature fluctuations, they must be
considered qualitative until these uncertainties are appreciably
reduced. The requirement that the fractional convective flux < 1,
places restrictions on these uncertainties which suggest that current
RMS<SUB>ΔT</SUB>(x)'s are too large.
---------------------------------------------------------
Title: Statistical Line Blanketing in
Arcturus. I. Blanketing-Coefficient Description of Observations
Authors: Edmonds, Frank N., Jr.
1973PASP...85...24E Altcode:
A statistical description of line blanketing is presented for Arcturus
(a Boo, K2 IlIp, V = +0.06) which is based on equivalent widths and
identifications of roughly 10,000 spectral lines within the wavelength
region AA3600-25,000 A. Equivalent-width contributions or blanketing
coefficients for lines grouped as to equivalent width and identification
are given for 100 A wavelength intervals for A < 9000 A and 500 A
intervals for A> 9000 A (Tables I and II). Strong lines are listed
individually (Table III), and the variation or scatter of blanketing
within intervals is described. Corrections to this description for
limitations in the observations and their analysis are discussed. Key
words: line blanketing - statistics of spectral lines - spectroscopy
---------------------------------------------------------
Title: Spectral Analyses of Solar Photospheric
Fluctuations. III. Bi-Dimensional Power, Coherence and Phase Spectra
of Deep-Seated Radial Velocity and Photometric Fluctuations
Authors: Edmonds, Frank N., Jr.; Webb, Carol J.
1972SoPh...25...44E Altcode:
Fluctuations measured from a time sequence of high-resolution,
high-dispersion Sacramento Peak Observatory spectrograms and
previously analyzed by computing one-dimensional temporal and spatial
spectra (Edmonds et al., 1965), are re-analyzed using bi-dimensional
(temporal and spatial) power, coherence and phase spectra computed by
fast-Fourier-transform techniques. The fluctuations measured are radial
velocity for the FeI 5049.83, CrI 5051.91 and CI 5052.16 spectral lines,
continuum brightness, and equivalent width and central intensity of the
CI line. The bidimensional spectra, particularly those of coherence
and phase, allow isolating different components of the fluctuations
to a degree not possible in the one-dimensional analyses.
---------------------------------------------------------
Title: Line Blanketing in Arcturus - Statistical Descriptions of
Observations.
Authors: Edmonds, F. N., Jr.; Morgan, T. E.
1972BAAS....4..236E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spectral Analyses of Solar Photospheric
Fluctuations. II. Profile Fluctuations in the Wings of the λ 5183. 6
MgI b<SUB>1</SUB> Line
Authors: Edmonds, Frank N., Jr.
1972SoPh...23...47E Altcode:
Residual intensity fluctuation measurements within the wings of the
λ5183.6 MgI b<SUB>1</SUB> line, obtained from two, high-resolution,
high-dispersion, Sacramento Peak Observatory spectrograms, have been
subtracted from intensity fluctuations in the adjacent continuum
in order to isolate fluctuations associated exclusively with line
formation. The useable spectral range for studying these lineformation
fluctuations is restricted to wavelengths between 1040 and 7170 km
because the subtraction increases the relative importance of noise
and large-scale photographic variations across the spectrograms
could not be completely removed. Power and cross-power (coherence and
phase) spectra proved to be valuable diagnostic tools in isolating
line-formation fluctuations.
---------------------------------------------------------
Title: Spectral Analyses of Solar Photospheric Fluctuations. I: Power,
Coherence and Phase Spectra Calculated by Fast-Fourier-Transform
Techniques
Authors: Edmonds, Frank N., Jr.; Webb, Carol J.
1972SoPh...22..276E Altcode:
The application of the fast-Fourier-transform (FFT) algorithm to
calculating one-dimensional and bi-dimensional (temporal and spatial),
power and cross-power (coherence and phase) spectra is examined for
solar photospheric fluctuations. Alternative methods for smoothing raw
spectra, direct averaging (employing various weights) and indirect
truncation of the correlation function, are compared, and indirect
smoothing is compared with spectra calculated by mean-lagged-product
(MLP) methods. Besides providing the raw spectrum, FFT techniques
easily allow computing a series of spectra with varying amounts of
smoothing. From these spectra a range of satisfactory compromise
between resolution and stability can be determined which helps in the
interpretation of spectral trends, and in identifying more clearly the
existence and significance of spectral features. For bi-dimensional
spectra presented as contour plots, this range of satisfactory smoothing
can be restricted, particularly when spectral trends must be represented
by small-scale contours. Equivalent spectra (i.e. comparable equivalent
degrees of freedom) computed or smoothed by different methods have
minor, but not negligible, differences. Examination of these differences
favors computing of FFT spectra smoothed by averaging for photospheric
fluctuations.
---------------------------------------------------------
Title: Line Blanketing in Arcturus - Statistical Descriptions of
Observations.
Authors: Edmonds, F. N.; Morgan, T. E.
1971BAAS....3..454E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Profile Fluctuations in the Wings of the λ5183.6 Mg b Line
Due to Solar Photospheric Inhomogeneities
Authors: Edmonds, Frank N., Jr.
1971BAAS....3....6E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Bidimensional (Spatial and Temporal) Power, Coherence, and
Phase Spectra for Solar Photospheric Spectral Lines
Authors: Edmonds, Frank N., Jr.; Webb, Carol Jean
1970BAAS....2..311E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Comparison of the Statistical Stability and Spectral
Resolution of Power Coherence and Phase Spectra of Solar Photospheric
Fluctuations as Evaluated by Fast-Fourier-Transform Techniques and
by the Mean-Lagged-Product Method
Authors: Edmonds, Frank N., Jr.; Webb, Carol Jean
1970BAAS....2Q.312E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Radial Velocity of Arcturus Determined from Interferometric
Spectra
Authors: Bopp, Bernard W.; Edmonds, Frank N., Jr.
1970PASP...82..299B Altcode:
From high-resolution, infrared, interferometric spectra, the radial
velocity of Arcturus is deterrnined by simple measurements between
superposed spectral tracings of the star and the sun. A velocity
of -5.47 1 0.07 km/sec obtained from metal lines is comparable to a
highly accurate result obtained by Petrie and Fletcher (1967) using
standard methods. A velocity of -5.82 1 0.18 obtained from CO lines
is interpreted in terms of a differentially expanding atmosphere.
---------------------------------------------------------
Title: The Infrared Spectrum of Arcturus
Authors: Montgomery, Earl F.; Connes, Pierre; Connes, Janine; Edmonds,
Frank N., Jr.
1969ApJS...19....1M Altcode:
Equivalent widths of 1036 stellar lines have been measured from
high-resolution interferometric spectra of Arcturus covering the
spectral range 876&3978 (1 129 A). Approximately 60 percent of
these lines have been identified.
---------------------------------------------------------
Title: The Infrared Spectrum of Arcturus
Authors: Montgomery, Earl F.; Connes, Pierre; Connes, Janine; Edmonds,
Frank N., Jr.
1969BAAS....1R.201M Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The McDonald Coudé Sensitometer
Authors: Edmonds, Frank N., Jr.
1969BAAS....1..150E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Radiative transfer within a stellar absorption line. The
contribution curves of fine-analysis methods.
Authors: Edmonds, F. N., Jr.
1969JQSRT...9.1427E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Contribution Curves in the Fine Analysis of Stellar Spectral
Lines.
Authors: Edmonds, Frank N., Jr.
1967AJ.....72R.793E Altcode:
Three methods for the fine analysis of spectral lines are: (1)
a straightforward combination of formulas arising from pertinent
formal solutions to the equation of radiative transfer; (2) the
Planckian-gradient method developed by Mugglestone; (3) the weight-
saturation method developed by Pecker and others. These three methods
are equivalent in that the formulas for one method can be obtained
from those of another by simple integration by parts. In each of the
three cases the formulas allow the computing of contribution curves
which presumably show the relative contribution to line formation
of the different layers of the model atmosphere used in the fine
analysis. Computer programs have been developed for the three methods
which compute the equivalent width and profiles of spectral lines under
the assumption of formation by pure absorption. These programs have
been designed to give contribution curves as well. The contribution
curves for the same line abundance-model atmosphere situation are
quite different for the three methods, and many of the properties of
contribution curves which have been determined previously, using the
weight saturation method, are not found in those for the formal solution
or Planckian-gradient methods. These results lead to the conclusion that
contribution curves are critically method dependent and do not provide
information about the depth dependence of line formation. Previous
determinations of effective depths of line formation based on or
related to contribution curves are therefore suspect. The differences
in the contribution curves of the three methods are such that the
weight-saturation method weights more heavily the contribution from the
upper layers of the atmosphere, while the Planckian-gradient method
gives the least weight to these layers. One might expect, therefore,
differences in equivalent widths and profiles computed by the different
methods because of this difference in weighting. In particular, a
method which weighted the most reliably determined layers of a model
atmosphere would be preferable. Calculations testing these possibilities
are under way, but results obtained so far indicate that differences
between the methods are small, except when layer-dependent factors,
such as the damping constant, critically affect equivalent widths.
---------------------------------------------------------
Title: Amplitude Distributions of Solar Photospheric Fluctuations
Authors: Edmonds, Frank N., Jr.
1967SoPh....1....5E Altcode:
Amplitude distributions, which are nearly Gaussian, have been calculated
for radial velocity, continuum brightness, spectral line equivalent
width and spectral line central residual intensity fluctuations measured
from high-dispersion high-resolution spectrograms taken at the center
of the solar disk. The RMS and skewness S for each distribution have
been calculated in a manner which allows testing of the homogeneity
of the granulation pattern (i.e. variations in its statistics across
the solar disk and with time). Pattern inhomogeneity across the disk
is strongly indicated, and further evidence suggesting appreciable
pattern persistence over time intervals ≳ 15 minutes is presented. The
possibilities for investigations of S and its associated bi-spectrum
are discussed. The qualitative values of S obtained are shown not
to be due to unusually bright, rising granules (though a statistical
tendency towards such granules is possible). An attempt to explain S for
continuum brightness fluctuations in terms of the nonlinear effects of
Planckian emission and opacity fluctuations in a stratified photosphere,
leads to contradiction with the measured amplitude distributions,
a contradiction which is probably due to an oversimplified treatment
of radiative transfer in an inhomogeneous photosphere.
---------------------------------------------------------
Title: Hydrogen-line Stark broadening functions
Authors: Edmonds, Frank N., Jr.; Schluter, Hans; Wells, Donald C.
1967MmRAS..71..271E Altcode: 1967MmRAS..70..271E
No abstract at ADS
---------------------------------------------------------
Title: A Spectrophotometric Analysis of Procyon. II. The Continuous
Spectrum and Line Blanketing
Authors: Talbert, Freddie D.; Edmonds, Frank N., Jr.
1966ApJ...146..177T Altcode:
Photoelectric spectral scans of Procyon (F5 IV-V), obtained at McDonald
Observatory, are combined with monochromatic magnitudes obtained by
other observers to determine a measured continuous spectrum extending
over the wavelength range X 3390-7460 and corrected for line blanketing
measured from high-dispersion spectrograms. Line-blanketing measurements
over the wavelength range X 3025- 4100 are also given. An attempt
is made, with partial success, to correct further the continuum in
the ultraviolet for blanketing by Balmer lines and unresolved lines,
using primarily a straight-line extrapolation method which assumes that
variations of color temperature with wavelength are small. Comparisons
made between the measured continuous spectrum and the emergent flux
predicted by a set of model atmospheres lead to the selection of a
model atmosphere for the star.
---------------------------------------------------------
Title: The Evidence for an Oscillatory Component in Solar Granulation
Brightness Fluctuations
Authors: Edmonds, Frank N., Jr.; McCullough, James R.
1966ApJ...144..754E Altcode:
The evidence for an oscillatory component of continuum brightness
fluctuations, secondary maxima in temporal autocorrelation functions
and power spectra, is examined critically with the provisional
conclusion that such a component is theoretically possible and
probably does exist. This component, with periods distributed about 5
min, constitutes between 0.5 and 2 per cent of the total fluctuation
power. The results from one analysis (725) suggest the coexistence of
a second oscillatory component with periods distributed about 10 min,
but the evidence is quite uncertain. There are also indications that
the effects of spectral windows may be masking a stronger concentration
of power of continuum brightness fluctuations to lower frequencies
---------------------------------------------------------
Title: A Coherence Analysis of Fraunhofer-Line Fine Structure and
Continuum Brightness Fluctutations Near the Center of the Solar
Disk. II
Authors: Edmonds, Frank N., Jr.
1966ApJ...144..733E Altcode:
Spatial cross-correlation analyses between fluctuations in radial
velocity, V, and continuum brightness, I, have been carried out for four
high-resolution spectrograms of the center of the solar disk obtained
by Michard at the Pic-du-Midi Observatory. These analyses employed a
coherence technique, and the results are quite similar to those recently
obtained from an analysis of Sacramento Peak Observatory spectrograms
by Edmonds, Michard, and Servajean. These results suggest that the
V fluctuations contain a large-scale oscillatory component poorly
correlated with the I fluctuations, and a smaller-scale convective
component sigiiificantly correlated with the I fluctuations. An improved
method for determining confidence limits for the results of a coherence
analysis is presented in the Appendix, and these limits are applied
to the results of four spatial coherence analyses. It is shown that
these and other estimates of random errors of the statistical analysis
cannot explain the differences between the different analyses. Whereas
instrumental and atmospheric blurring may be important causes of these
differences, it appears that for the most part they are real differences
between different samples of photospheric inhomogeneities. The effects
of the possible inclination of inhomogeneities found by Evans are
also discussed. Confidence limits estimates further show that small
variations with wavenumber k1 of power spectra and coherences cannot
be considered significant.
---------------------------------------------------------
Title: The Determination of the Ultraviolet Continuum of Procyon
from Balmer Line Profiles
Authors: Edmonds, F. N., Jr.
1966IAUS...26..159E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Observational studies of macroscopic inhomogeneities in the
solar atmosphere. VII. A statistical analysis of photometric and
kinematic inhomogeneities in the deep atmosphere
Authors: Edmonds, F. N.; Michard, R., Jr.; Servajean, R.
1965AnAp...28..534E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Asymmetry in the Brightness Fluctuations of Solar Granulation.
Authors: Edmonds, Frank N., Jr.
1965AJ.....70Q.674E Altcode:
Recent determination of the amplitude of solar photospheric temperature
fluctuations as a function of optical depth (Edmonds, F. N., Jr.,
Astrophys. J. 139, 1358) has been combined with the empirical model
atmosphere of Pierce and Waddell (Mem. Roy. Astron. Soc. 68, 89) to
calculate the skewness of source-function fluctuations and of emergent
intensity fluctuations for assumed Gaussian and skew Gaussian-like
distributions of the temperature fluctuations. These calculations
show the skewness introduced into the emergent intensity fluctuations
by the Planckian nature of the source function emission and by the
stratification of the continuum contributing layers. This skewness
is calculated as a function of position on the solar disk and is
compared with that determined from a statistical analysis of solar
granulation (Edmonds, F. N., Jr., Astrophys. J. Suppl. 6, 357). This
photometric asymmetry of the granulation pattern is distinguished
from the topological asymmetry (bright blobs surrounded by dark lanes)
which is a manifestation of the upper boundary of the solar hydrogen
convection zone.
---------------------------------------------------------
Title: The Continuous Spectrum and Line Blanketing for Procyon.
Authors: Talbert, F. D.; Edmonds, F. N., Jr.
1965AJ.....70Q.332T Altcode:
Low-dispersion photoelectric spectrum scans coupled with high-dispersion
coude' plates have been used to construct an empirical continuum
of Procyon corrected for line blanketing. Blanketing factors for
25 A intervals in the range XA30254100 have been determined. The
straight-line extrapolation method of Canavaggia and Chalonge has been
used to determine the continuum in the near ultraviolet, ~x3650#000,
and concordant results have been obtained from a determination based
on matching observed and computed profiles of the Balmer lines in
this wavelength range. Comparison of the empirical continuum with that
predicted by several model atmospheres calculated for Procyon indicate
moderate discrepancies in the ultraviolet. Possible causes for these
discrepancies are discussed.
---------------------------------------------------------
Title: A Set of Non-Gray Model Atmospheres for Procyon.
Authors: Edmonds, Frank N., Jr.
1964ApJ...140..902E Altcode:
A set of eight non-gray model atmospheres has been calculated for
the subgiant Procyon (F5 IV) using the Str6mgren-Swihart method for
determining a temperature-optical depth relation which maintains
constant flux. The eight models correspond to two values each of the
parameters Te (effective temperature), A (hydrogen-to-metal ratio),
and p (helium-to-hydrogen ratio). These models are compared with respect
to the variation with optical depth and/or wavelength of the following
properties: 0 = 5040/T, log Fe, log Pg, hydrogen convection zone, limb
darkening, and emergent flux with associated continuum contribution
functions. The problem of model selection (and parameter determination)
is discussed in general terms. The parameter Te can be obtained from
the observed continuous spectrum, but the parameters A and p cannot,
as would be expected for the spectral class F5 IV. The parameters A
and p cannot be determined effectively from the observed strengths of
weak spectral lines or from the Stark of the Balmer lines. Conversely,
the determination of these two parameters does not seem to be necessary
for a spectrophotometric analysis of weak lines.
---------------------------------------------------------
Title: Source-Function and Temperature Fluctuations in the Solar
Photosphere. I. The Isotropic Approximation.
Authors: Edmonds, Frank N., Jr.
1964ApJ...139.1358E Altcode:
Measurements of power spectra and RMS's for granulation brightness
fluctuations across the solar disk, as obtained from 1957 Stratoscope
photographs by Edmonds (1962), are used to determine source- function
and temperature fluctuations as a function of optical depth in the
solar photosphere. This involves the solving, by the Laplace-transform
method employing polynomials, of integral equations which are based
on an approximation of isotropy and which are quite similar to the
formal solution of the equation of radiative transfer. Limitations
imposed on the results by the measurements and the method employed are
discussed. Source-function and temperature fluctuations are presented
in Tables 2,3, and 4 and in Figures 3 and 4. These fluctuations
increase with optical depth r, this increase becoming more gradual or
leveling off around optical depth 1.5 as the result of the maximum
in the granulation brightness fluctuations which occurs at 0 500 on
the disk. The best determined RMS of temperature fluctuations at the
same opticat depth is approximately 880 K at r = 0.32, 2720 K at r =
0.80, 4540 K at r = 1.28, and 5140 K at r = 2.08. For the first three
of these optical depths, the RMS's at the same geometricat tevet are
880 K, 3600 K, and 7400 K.
---------------------------------------------------------
Title: On the Calculation of Equivalent Widths from Spectral-Line
Profiles. II.
Authors: Edmonds, Frank N., Jr.
1964ApJ...139.1017E Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Cross Correlation between Continuum Brightness and Radial
Velocity Fluctuations in the Solar Photosphere.
Authors: Edmonds, Frank N., Jr.
1964AJ.....69Q.540E Altcode:
Spatial coherence and phase analyses of the cross correlation
between continuum brightness and radial velocity fluctuations in
the solar photosphere have been completed for four bigh-resolution
spectrograms obtained by R. Michard at the Pic-du-Midi Observatory,
and from a time sequence of 60 spectrograms taken by J. W. Evans at
Sacramento Peak Observatory. The latter set includes the low-lying CI
line N5052.16, and its analysis is a joint effort with Dr. R. Michard
and Dr. R. Servajean at the Observatoire de Paris Meudon. The results
give mean cross-correlation coefficients for each set of 0.35 and
mean, nearly anti- phase coherences which are significant (>0.5)
in wavenumber ranges that lie between 10- and 2.5 X 1O-i km-'. These
results, together with earlier analyses (Edmonds, Astrophys. J. 136,
507,1962), indicate first that, in general, significant cross
correlation does exist between continuum brightness and radial
velocities fluctuations with scales less than 8000 km. Therefore,
thermal- driven convection is an appreciable physical cause of the
fluctuations. Secondly, there is considerable variation in behavior
between different samples of solar photospheric inhomogeneities,
these differences appearing in other statistical properties and in
the tracings of the fluctuations. That stronger cross correlation
is not found is possibly understandable in terms of the recent
discovery by Evans (to be published in A strophysica Norvegica;
also see abstract by J. W. Evans) that photospheric inhomogeneities
may be strongly inclined to the radial direction. There are problems
with this interpretation which arise from the small separation ($ 200
km) between layers of continuum formation and of line formation. An
analysis of the effects of random shifts in position on the solar disk
between radial velocity and continuum brightness fluctuations predicts
that orientation could reduce the cross-correlation coefficient only
to about 0.75 and reduce coherence correspondingly in a manner which
increases with wavenumber. Also, temporal coherence and phase analysis
(Evans Michard, and Servajean, Ann. d'Astrophys. 26, 368,1963), provides
a clearer picture as to the role played by oscillations (with periods
around 300 sec) which are an important component of the radial velocity
fluctuations but not of the contiuum brightness fluctuations. These
results, together with more recent power spectra computed by Michard and
Servajean suggest that whereas the oscillatory component is dominant
for optical depths &0.01, it is still appreciable in continuum-
forming depths >1.0.
---------------------------------------------------------
Title: On the Calculation of Equivalent Widths from Spectral-Line
Profiles.
Authors: Edmonds, Frank N., Jr.
1963ApJ...137..470E Altcode:
The determination of equivalent width from a line profile in terms
of Hjerting functions requires knowledge of the scale factor = A /V,
where AX is the displacement in wavelength from the line's center and V
is the Hjerting function argument. Tables are given in Section II which
will allow the determination of p for a profile Pk(AXk) evaluated only
at three values of AX,. Necessary factors to compute the equivalent
width, based on fitting a Hjerting function to these points, are also
tabulated. More general numerical integration formulae for determining
the equivalent width, based on Hjerting functions, are discussed in
Section III, and the weights and divisions V, are tabulated As shown
in Section IV, these formulae will give greater accuracy for fewer
divisions than methods now in use. For computed profiles, this should
effect a worthwhile reduction in computational effort.
---------------------------------------------------------
Title: A Coherence Analysis of Fraunhofer Line Fine Structures and
Continuum Brightness Fluctuations Near the Center of the Solar Disk.
Authors: Edmonds, Frank N., Jr.
1962ApJ...136..507E Altcode:
Cross-correlation analyses between fluctuations in radial velocity
V and continuum brightness I have been carried out for four sets of
measurements made near the center of the solar disk: those obtained
from a McMath-Hulbert spectrogram (w18), those of Richardson and
Schwarzschild (1950) (RS), those of Plaskett (1954) (P), and those
of Servajean (1961) (S). in addition, cross-correlation analyses
between fluctuations in line equivalent width W and fluctuations
in V and in I have been applied to the w18 measurements. These
analyses employed a coherence technique which gives the coherence
or cross- correlation between the Fourier components of the same
wavelength for each set of fluctuations and the phase difference
(across the solar disk) between these Fourier components (Figs. 4 5
6 8 10 12). The analyses also computed power spectra (Figs. 3, 7,
9, 11), r.m.s. `5, and filtered and unfiltered cross-correlations
(Table 2). A significant VI coherence with 180 phase difference was
found in the wavelength range km (on the surface of the sun) for the
RS measurements; no VI coherence was found for the w18 measurements;
and the S and P measurements gave inconclusive results. A significant
1W coherence with 1800 phase difference for wavelengths > 5000 km,
and no VW coherence was obtained for the w18 measurements. These results
cannot be explained in terms of differences in the solar atmosphere
levels making an appreciable contribution to line formation and to
continuum formation. The negative nature of the 1W cross-correlation
seemingly can be explained only in terms of 4-10 per cent increases
in the level of microturbulence for dark areas on the solar surface,
with corresponding decreases for the bright areas The inconsistent
picture presented by the four VI coherence analyses can be explained
in terms of a negative VI cross-correlation existing for wavelengths
< 5000 km plus certain differences in instrumental and atmospheric
resolution for the four sets of measurements. However, an explanation
in terms of a heterogeneous convection pattern at the sun's surface
seems more reasonable. The nature of the radial-velocity power spectra
and the effects producing a low cross-correlation are also discussed.
---------------------------------------------------------
Title: A Coherence Analysis of Fraunhofer Line Radial Velocity Fine
Structure and Continuum Brightness Fluctuations near the Center of
the Solar Disk.
Authors: Edmonds, Frank N., Jr.
1962AJ.....67Q.271E Altcode:
Cross correlation analyses between fluctuations in radial velocity
V and continuum brightness I have been carried out for four sets of
measurements made near the center of the solar disk; those obtained
from a McMath-Hulbert spectrogram (w18), those of R. S. Richardson
and M. Schwarzschild (Astrophys. J. 111, 351, 1950) (RS), those
of H. H. Plaskett (Monthly Notices Roy. Astron. Soc. 114, 251,
1954) (P), and those of R. Servajean (Ann. Astrophys. 24, 1, 1961)
(S). These analyses employed a coherence technique which gives the
coherence or cross correlation between the Fourier components of the
same wavelength for each set of fluctuations, and the phase difference
(across the solar disk) between these Fourier components. The analyses
also computed power spectra, RMS's and filtered and unfiltered cross
correlations. A significant VI coherence with 180~ phase difference
was found in the wavelength range 1200-5200 km (on the surface of
the sun) for the RS measurements, no VI coherence was found for the
w18 measurements, and the S and P measurements gave inconclusive
results. These results cannot be explained in terms of differences
in the solar atmosphere levels making an appreciable contribution to
line formation and to continuum formation. The inconsistent picture
presented by the four VI coherence analyses can be explained in terms
of a negative VI cross correlation existing for wavelengths ~ 5000 km
plus certain differences in instrumental and atmospheric resolution
for the four sets of measurements. However, an explanation in terms
of a heterogeneous convection pattern at the sun's surface seems
more reasonable.
---------------------------------------------------------
Title: A Statistical Photometric Analysis of Granulation across the
Solar Disk.
Authors: Edmonds, Frank N., Jr.
1962ApJS....6..357E Altcode:
Twenty-five microphotometer scans from Stratoscope granulation
photographs distributed across the solar disk have been analyzed
statistically to yield amplitude distributions, power spectra, and
related quantities. Power spectra have been calculated for twenty
additional scans of the center of the disk obtained by Schwarzschild
(1959). A difference in calibration procedures in part explains
RMS's that are nearly twice those obtained by sChwarzschild. The
range of wave numbers k1 for which power-spectra calculations yield
quantitative results is limited by uncertainties in low-wave-number
filtering to k1 > 0.001 km-' and by what is probably instrumental
noise in the photographs to k1 < 0.008 km-'. This upper limit
is further reduced to k1 < 0.004 km-' or less by instrumental
corrections, using the method of Uberoi (1955b) generalized for
foreshortening. These corrections account for the instrumental profile
of the Stratoscope (determined from the limb of the solar disk),for
focus of the photographs, and for the analyzing spot and focus of the
microphotometer. The variation in the relative brightness fluctuation
RMS across the solar disk (Figs. 4 and 9) is characterized by an
increase from 0.14 for the central regions of the disk (out to 0 20
, to 0.20 at 0 50 and then a sharper decrease, which levels off and
reverses itself at 0 70 . Ezamination of limb photographs attributes
this reversal to the emerging photometric importance of a large-scale,
essentially unforeshortened, pattern which does not seem to be
instrumental or telluric aild may not be part of the normal photosphere
granulation. Scatter in the RMS of adjacent scans can be attributed to
statistical inhomogeneities in the granulation pattern. The amplitude
distributions are approximately Gaussian (Fig. 3) with moderate positive
skewness. The power spectra (uncorrected, Tables 3 and 4 and Figs. 2
and 5; corrected, Table 8 and Fig. 10) are characterized by a rapid
decrease with increasing k,. A steepening of this falling-off toward
the limb is probably due to the large-scale pattern. The variation in
the brightness fluctuation RMS across the disk has been converted to
the RMS of temperature fluctuations as a function of optical depth,
using the Eddington-Barbier approximation (Fi . 11). The maximum of
brightness RMS at 0 50 becomes a maximum in temperature RMS of 290
K at r 0.65. An inhomogeneous model solar atmosphere based on these
temperature fluctuations has been constrncted (Table 9), and, using
the&etical results of Ledoux, Schwarzschild, and Spiegel (1961),
an associated velocity spectrum and convective transport have been
roughly determined. Scans of two special regions have been analyzed:
a region at the center of the disk, which is characterized by a low
RMS and a flattened spectrum, and a facular region, which shows the
normal spectrum and ouly a slightly higher RMS.
---------------------------------------------------------
Title: On Solar Granulation.
Authors: Edmonds, Frank N., Jr.
1960ApJ...131...57E Altcode:
From the examination of high-quality stratoscope photographs of solar
granulation it has been determined that the fading of the granulation
pattern occurs primarily in the region 60 < 0 < 78 and that
the fading granulation is replaced by a larger, low-contrast pattern
observable out to 0 87 . Inhomogeneities in the granulation pattern
have also been observed. These consist of low-contrast regions which
seem to persist for periods longer than 10 minutes and small-scale
regions which seem to evolve with the normal pattern
---------------------------------------------------------
Title: Letters to the Editor CA II Emission in the Spectrum of
Procyon.
Authors: Kraft, Robert P.; Edmonds, Frank N., Jr.
1959ApJ...129..522K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Coefficients of Viscosity and Thermal Conductivity in
the Hydrogen Convection Zone.
Authors: Edmonds, Frank N., Jr.
1957ApJ...125..535E Altcode:
The coefficient of viscosity, , the coefficient of thermal conductivity
by conduction, X , and the coefficient of the thermal conductivity by
radiation, X , have been calculated for stellar material (85 per cent
hydrogen, 15 per cent helium) over temperature and pressure ranges
which should include the hydrogen convection zones of most stars.
---------------------------------------------------------
Title: The DEBYE-HÜCKEL Effect and Statistical Theories for Collision
Broadening.
Authors: Edmonds, Frank N., Jr.
1956ApJ...123...95E Altcode:
The theory of Debye and for electrolytes is shown to be valid and
pertinent for ionized gases of astrophysical interest Corrections to
statistical theories of collision broadening due to the effect are shown
to be negligible in the cases of linear and quadratic Stark broadening
of the spectral lines of ions In Appendix I, Debye- effect corrections
are calculated for the related problem of the average distance to the
nearest charged particle.
---------------------------------------------------------
Title: Noncoherent Scattering due to Collisions. I. Zanstra's Ratio
of Coherent to Uncorrelated Noncoherent Scattering.
Authors: Edmonds, Frank N., Jr.
1955ApJ...121..418E Altcode:
A quantum-theory formulation of the problem of noncoherent scattering
due to collisions is presented in a general form and then made
equivalent to Zanstra's classical oscillator formulation by a set
of assumptions. These assumptions are examined critically as an
indirect method of determining whether Zanstra's results are correct
for statistical broadening. It would seem that Zanstra's ratio of
coherent to uncorrelated noncoherent scattering is too large by at
least a factor of 20, and the coherent component is not strictly
coherent. The validity of evaluating Zanstra's results for impact
broadening by this method is bnefly discussed.
---------------------------------------------------------
Title: Compton Scattering by Electron Atmospheres. II. Problems with
Incident Normal Flux.
Authors: Edmonds, Frank N., Jr.
1954ApJ...119..425E Altcode:
The problem of the transfer of radiation in an atinosphere of free
electrons is solved in the first approximation for two sets of boundary
conditions involving an incident normal flux, that of the planetary
nebula problem and that of no incident diffuse radiation field. In
the solution, account is taken of the noncoherent character of the
electron scattering due to the Doppler shifts arising from a Maxwellian
distribution of thermal velocities, the red shift of the Compton
effect, and a non-Doppler blue shift arising from thermal motions
and first pointed out by Dirac. The latter two effects, designated as
"Compton scattering," are shown to produce asymmetries in spectral lines
which would be very difficult to detect for very high temperatures,
as they are much smaller than the thermal broadening. In an appendix,
application of the solutions obtained to multiple Compton scattering
of low-energy gamma radiation is considered.
---------------------------------------------------------
Title: Compton Scattering by Electron Atmospheres. I. The Schuster
Problem.
Authors: Edmonds, Frank N., Jr.
1954ApJ...119...58E Altcode:
The problem of the transfer of radiation in an atmosphere of free
electrons is solved in the first approximation under the conditions
of the standard Schuster problem of line formation. In the solution,
account is taken of the noncoherent character of the electron scattering
due to the Doppler shifts arising from a Maxwellian distribution
of thermal velocities, the red shift of the Compton effect, and
a non-Doppler blue shift arising from thermal motions and first
pointed out by Dirac. The latter two effects, designated as "Compton
scattering," are shown to produce asymmetries in spectral lines which
would be very difficult to detect for stellar temperatures, as they
are much smaller than the thermal broadening.
---------------------------------------------------------
Title: Compton Scattering by Electrons with a Maxwellian Distribution
of Thermal Velocities.
Authors: Edmonds, Frank N., Jr.
1953ApJ...117..298E Altcode:
The theory of the Compton effect is applied to the problem of scattering
of radiation by electrons with a Maxwellian distribution of thermal
; and a spectral distribution function for scattered radiation is
obtnined in the second approximation. This function, equation (26), is
asymmetric, and the frequency shift of scattered radiation corresponding
to this asymmetry is given by - cos 0 - t m0 c2 (kv-3kT), where p is
the incident frequency, p' the scattered frequency, 0 the angle of
scattering, and the other symbols have their usual meaning. The red
shift in this expression is due to the Compton effect, while the blue
shift is a result of the thermal motions of the electrons, as first
pointed out by Dirac.
---------------------------------------------------------
Title: Scattering by a Moving Electron Atmosphere and its Effect on
Spectral LINES.I. the Schuster Problem.
Authors: Edmonds, Frank N., Jr.
1950ApJ...112..307E Altcode:
The problem of the transfer of radiation in an atmosphere of free
electrons undergoing differential expansion is solved in the first
approximation under the conditions of the standard Schuster problem
of line formation. It is further assumed that electron scattering
is in accordance with the frequency-independent Thomson scattering
coefficient, the Rayleigh phase function, and a Maxwellian distribution
of thermal velocities. In the solution, account is taken of the
noncoherent character of the scattering due to velocities arising
from the thermal and mass motions of the electrons. The solution
for radiation emerging from the atmosphere contains terms for
unscattered and scattered radiation. The latter contains a function
which represents the spectral distribution of scattered radiation for
incident monochromatic radiation. The shape of this function, which is
due to the thermal motions of the electrons, produces broad spectral
lines characterized by a shallow center and extended wings. Further,
a shift of this spectral distribution function resulting from the
differential expansion of the atmosphere produces asymmetries in
spectral lines. Two numerical examples of these effects have been
calculated.
---------------------------------------------------------
Title: Scattering by a Moving Electron Atmosphere and its Effect on
Spectral Lines. II. The Planetary Nebula Problem.
Authors: Edmonds, Frank N., Jr.
1950ApJ...112..324E Altcode:
The problem of the transfer of radiation in a planetary nebula
undergoing differential expansion and consisting of free electrons in
thermal motion is solved in the first approximation for the emergent
radiation. In the solution, account is taken of the noncoherent
character of the scattering, which is due to the thermal and mass
motions of the electrons. The solution for the emergent radiation
represents radiation of the incident flux from the central star, which
has suffered scattering by electrons in the nebula. The solution
contains a function which describes the spectral distribution of
scattered intensity for incident monochromatic flux. The shape of
this function produces in the solution a broadening of spectral lines
characterized by a shallow center and extended wings. A shift of this
function, due to the differential expansion of the nebula, produces
shifts in the lines. A numerical example has been worked out.
