Ca II K line profile of the truly quiet Sun

Solar Physics ◽  
1996 ◽  
Vol 163 (1) ◽  
pp. 93-97 ◽  
Author(s):  
K. R. Sivaraman ◽  
S. S. Gupta ◽  
R. Kariyappa
Keyword(s):  
Line Profile ◽  
Quiet Sun

scholarly journals Capabilities of bisector analysis of the Si I 10 827 Å line for estimating line-of-sight velocities in the quiet Sun

2020 ◽  
Vol 634 ◽  
pp. A19 ◽  
Author(s):  
S. J. González Manrique ◽  
C. Quintero Noda ◽  
C. Kuckein ◽  
B. Ruiz Cobo ◽  
M. Carlsson
Keyword(s):  
Spectral Line ◽  
Line Profile ◽  
Line Of Sight ◽  
Solar Telescope ◽  
Simple Method ◽  
Quiet Sun ◽  
Line Intensities ◽  
Line Core ◽  
Reference Images ◽  
Non Local

We examine the capabilities of a fast and simple method to infer line-of-sight (LOS) velocities from observations of the photospheric Si I 10 827 Å line. This spectral line is routinely observed together with the chromospheric He I 10 830 Å triplet as it helps to constrain the atmospheric parameters. We study the accuracy of bisector analysis and a line core fit of Si I 10 827 Å. We employ synthetic profiles starting from the Bifrost enhanced network simulation. The profiles are computed solving the radiative transfer equation, including non-local thermodynamic equilibrium effects on the determination of the atomic level populations of Si I. We found a good correlation between the inferred velocities from bisectors taken at different line profile intensities and the original simulation velocity at given optical depths. This good correlation means that we can associate bisectors taken at different line-profile percentages with atmospheric layers that linearly increase as we scan lower spectral line intensities. We also determined that a fit to the line-core intensity is robust and reliable, providing information about atmospheric layers that are above those accessible through bisectors. Therefore, by combining both methods on the Si I 10 827 Å line, we can seamlessly trace the quiet-Sun LOS velocity stratification from the deep photosphere to higher layers until around logτ = −3.5 in a fast and straightforward way. This method is ideal for generating quick-look reference images for future missions like the Daniel K. Inoue Solar Telescope and the European Solar Telescope, for example.

Contrast of Filament Bright Rims

1994 ◽  
Vol 144 ◽  
pp. 365-367
Author(s):  
E. V. Kononovich ◽  
O. B. Smirnova ◽  
P. Heinzel ◽  
P. Kotrč
Keyword(s):  
High Altitude ◽  
Line Profile ◽  
Line Center ◽  
Magnetic Structures ◽  
The Mean

AbstractThe Hα filtergrams obtained at Tjan-Shan High Altitude Observatory near Alma-Ata (Moscow University Station) were measured in order to specify the bright rims contrast at different points along the line profile (0.0; ± 0.25; ± 0.5; ± 0.75 and ± 1.0 Å). The mean contrast value in the line center is about 25 percent. The bright rims interpretation as the bases of magnetic structures supporting the filaments is suggested.

Interpretation of the Filament Depression at Millimetric and Centimetric Wavelengths

1979 ◽  
Vol 44 ◽  
pp. 131-134
Author(s):  
A. Raoult ◽  
P. Lantos ◽  
E. Fürst
Keyword(s):  
Radio Telescope ◽  
Active Regions ◽  
Simple Shape ◽  
Quiet Sun ◽  
Unstable Process

The depressions at centimetric and millimetric wavelengths associated with the filaments are studied using already published maps as well as unpublished observations from the Effelsberg 100 m radio telescope of the M.P.I., Bonn. The study has been restricted to large Ha quiescent prominences of relatively simple shape, situated far from the limb and from active regions. The data has been reduced employing one method whose main characteristics are choice of a local quiet sun definition and avoidance of the unstable process of deconvolution.

Frequency Redistribution Effects in the Formation of Lyman α in Prominences and Their Influence on the Ratio of Hα to Lα

1979 ◽  
Vol 44 ◽  
pp. 53-55
Author(s):  
R.W. Milkey ◽  
J.N. Heasley ◽  
E.J. Schmahl ◽  
O. Engvold
Keyword(s):  
Line Profile ◽  
Large Fraction ◽  
Partial Frequency ◽  
Frequency Redistribution ◽  
Partial Frequency Redistribution ◽  
Emergent Intensity

The effect of partial frequency redistribution in the formation of Lyman α in the chromosphere has been discussed by Milkey and Mihalas (1973) and others, and it has been shown that in this case the coherency of scattering in the wings of the line substantially influences the line profile. Although there are non-negligible sources for La photons within a prominence, a large fraction of the emergent line photons are due to scattering of photons incident on the surface of the prominence so that one expects that in a prominence the frequency redistribution processes will play an important role in determining the emergent intensity.

Microstructure of post-deformed ECAP-Ti investigated by Multiple X-Ray Line Profile Analysis

2006 ◽  
Vol 2006 (suppl_23_2006) ◽  
pp. 129-134 ◽  
Author(s):  
E. Schafler ◽  
K. Nyilas ◽  
S. Bernstorff ◽  
L. Zeipper ◽  
M. Zehetbauer ◽  
...  
Keyword(s):  
Line Profile ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
X Ray

Wind Inhomogeneities in Wolf-Rayet Stars. III. Unusual Emission-Line Profile Variations in [FORMULA][F]γ[SUP]2[/SUP][/F][/FORMULA] Velorum

1999 ◽  
Vol 117 (3) ◽  
pp. 1441-1453 ◽  
Author(s):  
Sébastien Lépine ◽  
Thomas Eversberg ◽  
Anthony F. J. Moffat
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Emission Line Profile

Emission-Line Diagnostics of T Tauri Magnetospheric Accretion. I. Line Profile Observations

1998 ◽  
Vol 116 (1) ◽  
pp. 455-468 ◽  
Author(s):  
James Muzerolle ◽  
Lee Hartmann ◽  
Nuria Calvet
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
T Tauri ◽  
Magnetospheric Accretion

Wind Inhomogeneities in Wolf‐Rayet Stars. II. Investigation of Emission‐Line Profile Variations

1999 ◽  
Vol 514 (2) ◽  
pp. 909-931 ◽  
Author(s):  
Sebastien Lepine ◽  
Anthony F. J. Moffat
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Emission Line Profile
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