TY - JOUR
T1 - X-ray spectra of the Fe-L complex: II. Atomic data constraints from the EBIT experiment and X-ray grating observations of Capella
AU - Gu, Liyi
AU - Shah, Chintan
AU - Mao, Junjie
AU - Raassen, Ton
AU - De Plaa, Jelle
AU - Pinto, Ciro
AU - Akamatsu, Hiroki
AU - Werner, Norbert
AU - Simionescu, Aurora
AU - Mernier, François
AU - Sawada, Makoto
AU - Mohanty, Pranav
AU - Amaro, Pedro
AU - Gu, Ming Feng
AU - Porter, F. Scott
AU - Crespo López-Urrutia, José R.
AU - Kaastra, Jelle S.
N1 - Project No. 266229290
UID/FIS/04559/2020
grant ST/R000743/1
grant agreement n. 871158
PY - 2020/9/1
Y1 - 2020/9/1
N2 - The Hitomi results for the Perseus cluster have shown that accurate atomic models are essential to the success of X-ray spectroscopic missions and just as important as the store of knowledge on instrumental calibration and astrophysical modeling. Preparing the models requires a multifaceted approach, including theoretical calculations, laboratory measurements, and calibration using real observations. In a previous paper, we presented a calculation of the electron impact cross sections on the transitions forming the Fe-L complex. In the present work, we systematically tested the calculation against cross-sections of ions measured in an electron beam ion trap experiment. A two-dimensional analysis in the electron beam energies and X-ray photon energies was utilized to disentangle radiative channels following dielectronic recombination, direct electron-impact excitation, and resonant excitation processes in the experimental data. The data calibrated through laboratory measurements were further fed into a global modeling of the Chandra grating spectrum of Capella. We investigated and compared the fit quality, as well as the sensitivity of the derived physical parameters to the underlying atomic data and the astrophysical plasma modeling. We further list the potential areas of disagreement between the observations and the present calculations, which, in turn, calls for renewed efforts with regard to theoretical calculations and targeted laboratory measurements.
AB - The Hitomi results for the Perseus cluster have shown that accurate atomic models are essential to the success of X-ray spectroscopic missions and just as important as the store of knowledge on instrumental calibration and astrophysical modeling. Preparing the models requires a multifaceted approach, including theoretical calculations, laboratory measurements, and calibration using real observations. In a previous paper, we presented a calculation of the electron impact cross sections on the transitions forming the Fe-L complex. In the present work, we systematically tested the calculation against cross-sections of ions measured in an electron beam ion trap experiment. A two-dimensional analysis in the electron beam energies and X-ray photon energies was utilized to disentangle radiative channels following dielectronic recombination, direct electron-impact excitation, and resonant excitation processes in the experimental data. The data calibrated through laboratory measurements were further fed into a global modeling of the Chandra grating spectrum of Capella. We investigated and compared the fit quality, as well as the sensitivity of the derived physical parameters to the underlying atomic data and the astrophysical plasma modeling. We further list the potential areas of disagreement between the observations and the present calculations, which, in turn, calls for renewed efforts with regard to theoretical calculations and targeted laboratory measurements.
KW - Atomic data
KW - Methods: laboratory: atomic
KW - Stars: coronae
KW - Techniques: spectroscopic
UR - http://www.scopus.com/inward/record.url?scp=85092776882&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202037948
DO - 10.1051/0004-6361/202037948
M3 - Article
AN - SCOPUS:85092776882
SN - 0004-6361
VL - 641
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A93
ER -