Spectral diagnostic for the soft X-ray Fe XVII spectral line in the solar corona

2016 ◽  
Vol 68 (8) ◽  
pp. 994-997 ◽  
Author(s):  
Jian He ◽  
Qingguo Zhang ◽  
Qiuze Li
Keyword(s):  
Spectral Line ◽  
Solar Corona ◽  
X Ray ◽  
Spectral Diagnostic

scholarly journals Calculations on the Solar Spectrum from 1 to 60 Å

1972 ◽  
Vol 14 ◽  
pp. 666-667 ◽  
Author(s):  
R. Mewe
Keyword(s):  
Spectral Line ◽  
Solar Corona ◽  
Radiation Intensity ◽  
Research Laboratory ◽  
Solar Spectrum ◽  
X Ray ◽  
Line Intensities ◽  
University College London ◽  
Set Up ◽  
The Continuum

Over two hundred spectral line intensities between 1 and 60 Å from ions in the solar corona have been computed for electron temperatures ranging between 105 and 109 K (Mewe, 1972a). Also the continuum (ff+fb) radiation intensity has been computed. The calculations were set up to interprete soft X-ray measurements aboard the ESRO 2B satellite (IRIS): Wavelength bands 44–55 Å (experiment of Space Research Laboratory, Utrecht) and 1–3, 3–9, 6–18 Å(expt. of University College, London) (Brinkman and Shaw, 1972).

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

SOFT X-RAY IMAGES OF THE SOLAR CORONA USING NORMAL INCIDENCE OPTICS

1988 ◽  
Vol 49 (C1) ◽  
pp. C1-115-C1-118 ◽  
Author(s):  
M. E. BRUNER ◽  
B. M. HAISCH ◽  
W. A. BROWN ◽  
L. W. ACTON ◽  
J. H. UNDERWOOD
Keyword(s):  
Solar Corona ◽  
Normal Incidence ◽  
X Ray

scholarly journals Silicon in the solar corona

1965 ◽  
Vol 23 ◽  
pp. 115-123
Author(s):  
K. G. Widing ◽  
J. R. Porter
Keyword(s):  
Solar Corona ◽  
Relative Intensity ◽  
Line Emission ◽  
X Ray ◽  
Resonance Transitions ◽  
Spectral Ranges

Resonance lines of coronal ions of silicon are prominent in the spectral ranges 40–62 Å and 254–356 Å.An unexpected feature of the soft X-ray spectrum is the weakness or absence of the resonance lines of iron in ionization stages XI through XV.A second feature is the prominence of lines of the type (3d → 2p) relative to the resonance transitions (3p → 2s) in Li-like and Beryllium-like spectra. It is suggested that the upper levels (3d) are excited by quadrupole collisions from the ground 2s or 2s2levels.The intensity of the soft X-ray lines relative to the resonance lines in the 300 Å region seems to be more consistent with temperatures well above one million degrees than with temperatures as low as 700000°K, but the data are not adequate for a precise comparison. The relative intensity of the line emission from the various stages of silicon ionization may be interpreted as indicating that the ionization of silicon peaks in stages IX and X.The abundances of C, Mg, S, and Al relative to silicon do not seem to be greatly different from the chromospheric abundances reported by Pottasch or with the photospheric abundances.

scholarly journals Measuring the supermassive black hole parameters with space missions

2006 ◽  
Vol 2 (S238) ◽  
pp. 475-476
Author(s):  
Alexander F. Zakharov
Keyword(s):  
Black Hole ◽  
Spectral Line ◽  
Accretion Disks ◽  
Seyfert Galaxies ◽  
Emission Lines ◽  
X Ray ◽  
Line Shapes ◽  
Supermassive Black Hole ◽  
Broad Emission ◽  
Different Types

AbstractRecent X-ray observations of microquasars and Seyfert galaxies reveal broad emission lines in their spectra, which can arise in the innermost parts of accretion disks. Recently Müller & Camenzind (2004) classified different types of spectral line shapes and described their origin. Zakharov (2006b) clarified their conclusions about an origin of doubled peaked and double horned line shapes in the framework of a radiating annulus model and discussed s possibility to evaluate black hole parameters analyzing spectral line shapes.

All-sky hard X-ray spectral line survey with EXIST

2006 ◽  
Vol 50 (7-8) ◽  
pp. 637-639
Author(s):  
G.J. Fishman ◽  
J.E. Grindlay ◽  
J. Hong ◽  
D.H. Hartmann ◽  
S. Vadawale ◽  
...  
Keyword(s):  
Spectral Line ◽  
X Ray ◽  
Line Survey

X-Ray Observations Of an Over-the-limb Solar Flare with Large Spectral Line Shifts

1996 ◽  
pp. 557-558 ◽  
Author(s):  
A. C. Sterling ◽  
L. K. Harra-Murnion ◽  
H. S. Hudson ◽  
J. R. Lemen ◽  
K. T. Strong
Keyword(s):  
Solar Flare ◽  
Spectral Line ◽  
X Ray

scholarly journals MHD Aspects of Coronal Transients

1980 ◽  
Vol 91 ◽  
pp. 263-277 ◽  
Author(s):  
U. Anzer
Keyword(s):  
Solar Corona ◽  
Time Scales ◽  
White Light ◽  
Solar Flares ◽  
Great Length ◽  
X Ray

If one defines coronal transients as events which occur in the solar corona on rapid time scales (≲ several hours) then one would have to include a large variety of solar phenomena: flares, sprays, erupting prominences, X-ray transients, white light transients, etc. Here we shall focus our attention on the latter two phenomena; solar flares have been discussed at great length in a recent Skylab workshop and IAU Colloqium No. 44 was devoted to the study of prominences. Coronal transients, in the narrower sense, were first seen with the instruments on board of Skylab, both in the optical and the X-ray part of the spectrum.

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