atomic data for Fe L-shell complex & Hitomi (trac #426)

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reported by: @CloudyLex

X-ray spectra of the Fe-L complex Gu, L., Raassen, A. J. J., Mao, J., de Plaa, J., Shah, C., Pinto, C., Werner, N., Simionescu, A., Mernier, F., & Kaastra, J. S. 2019, arXiv e-prints, ,

ABSTRACT: The Hitomi results on the Perseus cluster lead to improvements in our knowledge of atomic physics which are crucial for the precise diagnostic of hot astrophysical plasma observed with high-resolution X-ray spectrometers. However, modeling uncertainties remain, both within but especially beyond Hitomi's spectral window. A major challenge in spectral modeling is the Fe-L spectrum, which is basically a complex assembly of n>2 to n=2 transitions of Fe ions in different ionization states, affected by a range of atomic processes such as collisional excitation, resonant excitation, radiative recombination, dielectronic recombination, and innershell ionization. In this paper we perform a large-scale theoretical calculation on each of the processes with the flexible atomic code (FAC), focusing on ions of Fe XVII to Fe XXIV that form the main body of the Fe-L complex. The new data are found to be consistent within 20% with the recent individual R-matrix calculations for the main Fe-L lines. By further testing the new FAC calculations with the high-quality RGS data from 15 elliptical galaxies and galaxy clusters, we note that the new model gives systematically better fits than the current SPEX v3.04 code, and the mean Fe abundance decreases by 12%, while the O/Fe ratio increases by 16% compared with the results from the current code. Comparing the FAC fit results to those with the R-matrix calculations, we find a temperature-dependent discrepancy of up to ~10% on the Fe abundance between the two theoretical models. Further dedicated tests with both observed spectra and targeted laboratory measurements are needed to resolve the discrepancies, and ultimately, to get the atomic data ready for the next high-resolution X-ray spectroscopy mission.

KEYWORDS: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Physics - Atomic Physics

LOCAL FILE : ~/Dropbox/literature/atomic_data/X-ray/Gu.L19X-ray-spectra-of-the-Fe-L-complex.pdf REMOTE URL : http://arxiv.org/abs/1905.07871 REMOTE URL : https://ui.adsabs.harvard.edu/abs/2019arXiv190507871G ADS URL : https://ui.adsabs.harvard.edu/abs/2019arXiv190507871G

Migrated from https://www.nublado.org/ticket/426

{
    "status": "new",
    "changetime": "2019-06-02T13:17:25Z",
    "_ts": "1559481445247993",
    "description": "X-ray spectra of the Fe-L complex \nGu, L., Raassen, A. J. J., Mao, J., de Plaa, J., Shah, C., Pinto, C., Werner, N., Simionescu, A., Mernier, F., & Kaastra, J. S.\n2019, arXiv e-prints, , \n\nABSTRACT: The Hitomi results on the Perseus cluster lead to improvements in our knowledge of atomic physics which are crucial for the precise diagnostic of hot astrophysical plasma observed with high-resolution X-ray spectrometers. However, modeling uncertainties remain, both within but especially beyond Hitomi's spectral window. A major challenge in spectral modeling is the Fe-L spectrum, which is basically a complex assembly of n>2 to n=2 transitions of Fe ions in different ionization states, affected by a range of atomic processes such as collisional excitation, resonant excitation, radiative recombination, dielectronic recombination, and innershell ionization. In this paper we perform a large-scale theoretical calculation on each of the processes with the flexible atomic code (FAC), focusing on ions of Fe XVII to Fe XXIV that form the main body of the Fe-L complex. The new data are found to be consistent within 20% with the recent individual R-matrix calculations for the main Fe-L lines. By further testing the new FAC calculations with the high-quality RGS data from 15 elliptical galaxies and galaxy clusters, we note that the new model gives systematically better fits than the current SPEX v3.04 code, and the mean Fe abundance decreases by 12%, while the O/Fe ratio increases by 16% compared with the results from the current code. Comparing the FAC fit results to those with the R-matrix calculations, we find a temperature-dependent discrepancy of up to ~10% on the Fe abundance between the two theoretical models. Further dedicated tests with both observed spectra and targeted laboratory measurements are needed to resolve the discrepancies, and ultimately, to get the atomic data ready for the next high-resolution X-ray spectroscopy mission.\n\nKEYWORDS: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Physics - Atomic Physics\n\nLOCAL FILE : ~/Dropbox/literature/atomic_data/X-ray/Gu.L19X-ray-spectra-of-the-Fe-L-complex.pdf\nREMOTE URL : http://arxiv.org/abs/1905.07871\nREMOTE URL : https://ui.adsabs.harvard.edu/abs/2019arXiv190507871G\nADS URL : https://ui.adsabs.harvard.edu/abs/2019arXiv190507871G\n",
    "reporter": "gary",
    "cc": "",
    "resolution": "",
    "time": "2019-06-02T13:17:25Z",
    "component": "atomic/molecular data base",
    "summary": "atomic data for Fe L-shell complex & Hitomi",
    "priority": "good to do",
    "keywords": "",
    "version": "",
    "milestone": "no milestone",
    "owner": "nobody",
    "type": "enhancement"
}