scholarly journals Atomic Physics Calculations for Iron L-line Spectra

2005 ◽  
Vol 13 ◽  
pp. 627-629
Author(s):  
Jacques Dubau ◽  
Delphine Porquet ◽  
Oleg Zabaydullin
Keyword(s):  
Solar Corona ◽  
Atomic Physics ◽  
Theoretical Approach ◽  
Emission Lines ◽  
Atomic Data ◽  
Iron Ions ◽  
X Ray ◽  
Upper Level ◽  
New Generation

AbstractAbsorption L-lines of iron ions are observed, in spectra of Seyfert 1 galaxies by the new generation of X-ray satellites: Chandra and XMM-Newton. Lines associated to Fe 23+ to Fe16+ have been already observed in emission, in the solar corona and in laboratory. Whereas, those corresponding to Fe 15+ to Fe6+ have not been observed as emission lines, the upper level of the transition decaying preferentially by autoionization. Many atomic data are available for the first ion set. For the second set, some data have been recently published for n=2 to n’=3 transitions. We have recalculated them using another theoretical approach and have extended them to n’=4.

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 .

ATOMIC PHYSICS RESEARCHES AT COOLER STORAGE RING IN LANZHOU

2009 ◽  
Vol 18 (02) ◽  
pp. 373-380 ◽  
Author(s):  
◽  
X. MA ◽  
X. H. CAI ◽  
X. L. ZHU ◽  
S. F. ZHANG ◽  
...  
Keyword(s):  
Electron Beam ◽  
Atomic Physics ◽  
Laser Cooling ◽  
X Ray ◽  
Density Distributions ◽  
Ion Interactions ◽  
Main Ring ◽  
Argon Ions ◽  
New Generation ◽  
Charged Ions

The commissioning of the cooler storage rings (CSR) was successful, and the facility provides new possibilities for atomic physics with highly charged ions. Bare carbon, argon ions, were successfully stored in the main ring CSRm, cooled by cold electron beam, and accelerated up to 1 GeV/u. Heavier ions as Xe 44+ and Kr 28+ were also successfully stored in the CSRs. Both of the rings are equipped with new generation of electron coolers which can provide different electron beam density distributions. Electron-ion interactions, high precision X-ray spectroscopy, complete kinematical measurements for relativistic ion-atom collisions will be performed at CSRs. Laser cooling of heavy ions are planned as well. The physics programs and the present status will be summarized.

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 Probing X-ray Emitting Plasma with High Resolution Chandra and XMM-Newton Spectra

2005 ◽  
Vol 13 ◽  
pp. 618-621
Author(s):  
Julia C. Lee
Keyword(s):  
High Resolution ◽  
Atomic Physics ◽  
Theoretical Calculations ◽  
Atomic Data ◽  
Experimental Measurements ◽  
Edge Structure ◽  
X Ray

AbstractHighlights of interesting astrophysical discoveries are reviewed in the context of high resolution X-ray spectroscopy made possible with Chandra and XMM-Newton, and its relevance to atomic physics calculations and measurements is discussed. These spectra have shown that the overlap between astrophysics and atomic physics is stronger than ever, as discoveries of new X-ray lines and edge structure is matching the need for increasingly detailed theoretical calculations and experimental measurements of atomic data.

scholarly journals X-Ray and EUV Spectra of Solar Flares and Laboratory Plasmas

1975 ◽  
Vol 68 ◽  
pp. 165-181 ◽  
Author(s):  
G. A. Doschek
Keyword(s):  
Solar Flare ◽  
Solar Flares ◽  
Emission Lines ◽  
Laboratory Work ◽  
Iron Ions ◽  
X Ray ◽  
Laboratory Plasmas ◽  
Euv Spectrum ◽  
Recent Laboratory

Recent laboratory work relevant to solar flares on the spectroscopy of highly ionized atoms is reviewed. Much of this work has concerned the X-ray and EUV spectrum of iron ions, Fe XVIII–Fe XXIV, which produce prominent emission lines in the spectra of solar flares. Also discussed are recently obtained laboratory X-ray spectra of emission lines of hydrogen-like and helium-like ions, and associated satellite lines due to transitions of the type, 1s2l—2p2l, 1s22l—1s2p2l, and 1s22l— —1s2l3p. Satellite lines have also been identified in spectra of solar flares, and can be used to determine the electron temperature of the plasma. The laboratory work is important in the planning of future experiments in solar flare X-ray and EUV spectroscopy.

scholarly journals PyAtomDB: Extending the AtomDB Atomic Database to Model New Plasma Processes and Uncertainties

Atoms ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 49
Author(s):  
Adam R. Foster ◽  
Keri Heuer
Keyword(s):  
Software Package ◽  
Extreme Ultraviolet ◽  
Emission Lines ◽  
Atomic Data ◽  
Model Calculations ◽  
X Ray ◽  
Hot Plasma ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Spectrum Generation

The AtomDB project provides models of X-ray and extreme ultraviolet emitting astrophysical spectra for optically thin, hot plasma. We present the new software package, PyAtomDB, which now underpins the entire project, providing access to the underlying database, collisional radiative model calculations, and spectrum generation for a range of models. PyAtomDB is easily extensible, allowing users to build new tools and models for use in analysis packages such as XSPEC. We present two of these, the kappa and ACX models for non-Maxwellian and Charge-Exchange plasmas respectively. In addition, PyAtomDB allows for full open access to the apec code, which underlies all of the AtomDB spectra and has enabled the development of a module for estimating the sensitivity of emission lines and diagnostic line ratios to uncertainties in the underlying atomic data. We present these publicly available tools and results for several X-ray diagnostics of Fe L-shell ions and He-like ions as examples.

scholarly journals Atomic Data Needed for Solar Astronomy from Space

1992 ◽  
Vol 9 ◽  
pp. 569-570
Author(s):  
Jacques Dubau
Keyword(s):  
Transition Region ◽  
Temporal Resolution ◽  
Upper Atmosphere ◽  
Emission Lines ◽  
Atomic Data ◽  
X Ray ◽  
The Earth ◽  
Space Observatories ◽  
Solar Astronomy

The UV and X-ray wavelength ranges are rich in emission unes from the transition region and the corona, formed at temperatures from 104 K to 107 K. Fortunately, these emission lines, absorbed by the earth upper atmosphere, can be observed by some solar space observatories. In particular, the NASA SMM satellite, from 1980 to 1990, has obtained very interesting spectra from which important solar results were derived. In a close future, they will be again observed but with improved spectral, spatial and temporal resolution by SOLAR-A and SOHO.

scholarly journals The solar corona above active regions: a comparison of extreme ultraviolet line emission with radio emission

1968 ◽  
Vol 35 ◽  
pp. 404-410 ◽  
Author(s):  
Werner M. Neupert
Keyword(s):  
Active Region ◽  
Radio Emission ◽  
Solar Corona ◽  
Extreme Ultraviolet ◽  
Line Emission ◽  
Active Regions ◽  
Emission Lines ◽  
Line Radiation ◽  
X Ray ◽  
Spot Group

The observations of extreme ultraviolet (EUV) emission lines of Feix through Fe XVI made by OSO-I have been applied to a study of the solar corona above active regions. Ultraviolet and radio emission are determined for several levels of activity classified according to the type of sunspot group associated with the active region. Both radio emission and line radiation from Fe XVI, the highest stage of ionization of Fe observed, are observed to increase rapidly with the onset of activity and are most intense over an E spot group early in the lifetime of the active region. As activity diminishes, radiation from Fe XV and Fe XIV becomes relatively more prominent. Preliminary X-ray data from OSO-III obtained during a flare are introduced. These indicate that radiation from the highest stage of iron thus far observed, Fe XXV, reaches a maximum first in an X-ray burst and that maxima in lower stages of ionization follow, with delays from 2 to 15 min.

scholarly journals PyAtomDB: Extending the AtomDB Atomic Database to Model New Plasma Processes and Uncertainties

2020 ◽  
Author(s):  
Adam R. Foster ◽  
Keri Heuer
Keyword(s):  
Open Access ◽  
Software Package ◽  
Emission Lines ◽  
Atomic Data ◽  
Model Calculations ◽  
X Ray ◽  
Hot Plasma ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Spectrum Generation

The AtomDB project provides models of X-ray and EUV emitting astrophysical spectra for optically thin, hot plasma. We present the new software package, PyAtomDB, which now underpins the entire project, providing access to the underlying database, collisional radiative model calculations, and spectrum generation for a range of models. PyAtomDB is easily extensible allowing users to build new tools and models for use in analysis packages such as XSPEC. We present two of these, the kappa and ACX models for non-Maxwellian and Charge-Exchange plasmas respectively. In addition, PyAtomDB allows full open access to the apec code which underlies all of the AtomDB spectra and has enabled development of a module for estimating the sensitivity of emission lines and diagnostic line ratios to uncertainties in the underlying atomic data. We present these publicly available tools and results for several X-ray diagnostics of Fe L-shell ions and He-like ions as examples.

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.

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