Atomic data needed for analysis of EUV and X-Ray spectra

2006 ◽  
pp. 43-50
Author(s):  
John C. Raymond
Keyword(s):  
Atomic Data ◽  
X Ray

Atomic physics calculations relevant to solar flare spectra

1991 ◽  
Vol 336 (1643) ◽  
pp. 471-484 ◽  
Keyword(s):  
Solar Flare ◽  
Atomic Physics ◽  
Solar Flares ◽  
Solar Maximum ◽  
Emission Lines ◽  
Atomic Data ◽  
Solar Maximum Mission ◽  
X Ray ◽  
Physical Conditions ◽  
Recombination Processes

Solar flare spectra in the ultraviolet and X-ray wavelength regions are rich in emission lines from highly ionized ions, formed at temperatures around 10 7 K. These lines can be used as valuable diagnostics for probing the physical conditions in solar flares. Such analyses require accurate atomic data for excitation, ionization and recombination processes. In this paper, we present a review of work which has already been carried out, in particular for the Solar Maximum Mission observations, and we look to future requirements for Solar-A .

scholarly journals Atomic Data Needed for X-ray and EUV Astronomy

1992 ◽  
Vol 9 ◽  
pp. 573-574
Author(s):  
John C. Raymond
Keyword(s):  
Spectral Resolution ◽  
Atomic Data ◽  
Ionization State ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Transmission Grating ◽  
Elemental Abundances ◽  
The Past ◽  
Accurate Temperature

AbstractThe astronomical X-ray and EUV satellites of the past generally had low enough spectral resolution that atomic data of modest quality was sufficient for most interpretation of the data. Typical proportional counter resolution Δ E/E ~ 1 permits a determination of the spectral shape sufficient for an estimate of the temperature of the emitting gas, but only the Fe K feature at 6.7 keV stands out as a distinct emission line. The higher spectral resolution Einstein Transmission Grating, Solid State Spectrometer, and Focal Plane Crystal Spectrometer instruments measured a score of emission lines or line blends, permitting determinations of the elemental abundances, temperature, and ionization state of the emitting gas. The higher spectral resolution and throughput of the BBXRT aboard the ASTRO mission and the instruments planned for EUVE, ASTRO-D, AXAF, and XMM will make possible a far more detailed analysis of the data. It should be possible to derive better abundances for more elements, accurate temperature distributions, electron densities, and accurate ionization states.

scholarly journals TIPTOPbase

2005 ◽  
Vol 13 ◽  
pp. 662-665
Author(s):  
P. Palmeri ◽  
C. Mendoza
Keyword(s):  
Atomic Structure ◽  
Atomic Data ◽  
Virtual Observatory ◽  
X Ray ◽  
Atomic Structure Calculations ◽  
Structure Calculations

AbstractAn overview of the online atomic database referred to as TIPTOPbase is given, in particular its opacity server (OPserver) and current developments regarding online atomic structure calculations. Efforts to include atomic data for X-ray line modeling and to integrate TIPTOPbase within the International Virtual Observatory Alliance (IVOA) are also mentioned.

scholarly journals Atmospheric NLTE models for the spectroscopic analysis of blue stars with winds

2020 ◽  
Vol 642 ◽  
pp. A172
Author(s):  
J. Puls ◽  
F. Najarro ◽  
J. O. Sundqvist ◽  
K. Sen
Keyword(s):  
High Performance ◽  
Extreme Ultraviolet ◽  
Numerical Models ◽  
Atomic Data ◽  
Perfect Agreement ◽  
X Ray ◽  
Spectrum Synthesis ◽  
Representative Model ◽  
Evolutionary Paths ◽  
Uv Range

Context. Obtaining precise stellar and wind properties and abundance patterns of massive stars is crucial to understanding their nature and interactions with their environments, as well as to constrain their evolutionary paths and end-products. Aims. To enable higher versatility and precision of the complete ultraviolet (UV) to optical range, we improve our high-performance, unified, NLTE atmosphere and spectrum synthesis code FASTWIND. Moreover, we aim to obtain an advanced description of X-ray emission from wind-embedded shocks, consistent with alternative modeling approaches. Methods. We include a detailed comoving frame radiative transfer for the essential frequency range, but still apply methods that enable low turnaround times. We compare the results of our updated computations with those from the alternative code CMFGEN, and our previous FASTWIND version, for a representative model grid. Results. In most cases, our new results agree excellently with those from CMFGEN, both regarding the total radiative acceleration, strategic optical lines, and the UV-range. Moderate differences concern He II λλ4200-4541 and N V λλ4603-4619. The agreement regarding N III λλ4634−4640−4642 has improved, though there are still certain discrepancies, mostly related to line overlap effects in the extreme ultraviolet, depending on abundances and micro-turbulence. In the UV range of our coolest models, we find differences in the predicted depression of the pseudo-continuum, which is most pronounced around Lyα. This depression is larger in CMFGEN, and related to different Fe IV atomic data. The comparison between our new and previous FASTWIND version reveals an almost perfect agreement, except again for N V λλ4603-4619. Using an improved, depth-dependent description for the filling factors of hot, X-ray emitting material, we confirm previous analytic scaling relations with our numerical models. Conclusions. We warn against uncritically relying on transitions, which are strongly affected by direct or indirect line-overlap effects. The predicted UV-continuum depression for the coolest grid-models needs to be checked, both observationally, and regarding the underlying atomic data. Wind lines from “super-ionized” ions such as O VI can, in principle, be used to constrain the distribution of wind-embedded shocks. The new FASTWIND version v11 is now ready to be used.

scholarly journals Atomic Calculations for the Highly Ionized Iron Ions Produced in Solar Flares

1984 ◽  
Vol 86 ◽  
pp. 141-142
Author(s):  
H.E. Mason ◽  
A.K. Bhatia
Keyword(s):  
Electron Scattering ◽  
Solar Flares ◽  
Electron Collision ◽  
Atomic Data ◽  
Proton Scattering ◽  
Iron Ions ◽  
X Ray ◽  
University College London ◽  
The University ◽  
Pair Coupling

The XUY (90–150 Å) and X-ray (10–25 Å) spectra of solar flares are rich in lines from the highly ionized iron ions. Atomic data have been calculated for Fe XVIII (Bhatia, unpublished), Fe XIX (Loulergue et al., 1984, Bhatia and Mason, 1984), Fe XX (Mason and Bhatia, 1980, 1983), Fe XXI (Mason et al., 1979), Fe XXII (Mason and Storey, 1980), Fe XXIII (Bhatia and Mason, 1981), Fe XXIV (Hayes, 1979). The University College London computer package was used. This consists of an atomic structure code (SUPERSTRUCTURE, Eissner et al., 1974); a ‘distorted wave’ electron scattering program (COLLDW, Eissner and Seaton, 1972); a ‘Bethe’ approximation electron scattering program (Burgess and Shoerey, unpublished); a program for obtaining electron collision strength in pair coupling from R matrices in LS coupling (JAJOM, Saraph, 1972); a proton scattering program (Bely and Faucher, 1970) and a program for obtaining level populations and intensity ratios.

scholarly journals Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi*

2018 ◽  
Vol 70 (2) ◽  
Author(s):  
Hitomi Collaboration, Felix Aharonian ◽  
Hiroki Akamatsu ◽  
Fumie Akimoto ◽  
Steven W Allen ◽  
Lorella Angelini ◽  
...  
Keyword(s):  
High Resolution ◽  
Atomic Data ◽  
Spectral Modeling ◽  
X Ray ◽  
Perseus Cluster

scholarly journals UPDATED ATOMIC DATA AND CALCULATIONS FOR X-RAY SPECTROSCOPY

2012 ◽  
Vol 756 (2) ◽  
pp. 128 ◽  
Author(s):  
A. R. Foster ◽  
L. Ji ◽  
R. K. Smith ◽  
N. S. Brickhouse
Keyword(s):  
Atomic Data ◽  
X Ray
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