Cyclotron resonant scattering feature simulations: I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling

Journal article
(Original article)


Publication Details

Author(s): Schwarm FW, Schönherr G, Falkner S, Pottschmidt K, Wolff M, Becker PA, Sokolova-Lapa E, Klochkov D, Ferrigno C, Fuerst F, Hemphill PF, Marcu-Cheatham DM, Dauser T, Wilms J
Journal: Astronomy & Astrophysics
Publisher: EDP Sciences
Publication year: 2017
Volume: 597
ISSN: 1432-0746
Language: English


Abstract


Context. Electron cyclotron resonant scattering features (CRSFs) are observed as absorption-like lines in the spectra of X-ray pulsars. A significant fraction of the computing time for Monte Carlo simulations of these quantum mechanical features is spent on the calculation of the mean free path for each individual photon before scattering, since it involves a complex numerical integration over the scattering cross section and the (thermal) velocity distribution of the scattering electrons. Aims. We aim to numerically calculate interpolation tables which can be used in CRSF simulations to sample the mean free path of the scattering photon and the momentum of the scattering electron. The tables also contain all the information required for sampling the scattering electron's final spin. Methods. The tables were calculated using an adaptive Simpson integration scheme. The energy and angle grids were refined until a prescribed accuracy is reached. The tables are used by our simulation code to produce artificial CRSF spectra. The electron momenta sampled during these simulations were analyzed and justified using theoretically determined boundaries. Results. We present a complete set of tables suited for mean free path calculations of Monte Carlo simulations of the cyclotron scattering process for conditions expected in typical X-ray pulsar accretion columns (0:01 ≤ B/B ≤ 0.12, where B = 4.413 × 10 G, and 3 keV ≤ kT ≤ 15 keV). The sampling of the tables is chosen such that the results have an estimated relative error of at most 1=15 for all points in the grid. The tables are available online (see link in footnote, page 1).


FAU Authors / FAU Editors

Dauser, Thomas Dr.
Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut
Falkner, Sebastian Dr.
Professur für Astronomie und Astrophysik
Schönherr, Gabriele Dr.
Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut
Schwarm, Fritz-Walter
Professur für Astronomie und Astrophysik
Sokolova-Lapa, Ekaterina
Professur für Astronomie und Astrophysik
Wilms, Jörn Prof. Dr.
Professur für Astronomie und Astrophysik


External institutions with authors

Eberhard Karls Universität Tübingen
European Space Astronomy Centre (ESAC)
George Mason University
Massachusetts Institute of Technology (MIT)
University of Geneva / Université de Genève (UNIGE)
University of Maryland, Baltimore County
U.S. Naval Research Laboratory


How to cite

APA:
Schwarm, F.-W., Schönherr, G., Falkner, S., Pottschmidt, K., Wolff, M., Becker, P.A.,... Wilms, J. (2017). Cyclotron resonant scattering feature simulations: I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling. Astronomy & Astrophysics, 597. https://dx.doi.org/10.1051/0004-6361/201629352

MLA:
Schwarm, Fritz-Walter, et al. "Cyclotron resonant scattering feature simulations: I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling." Astronomy & Astrophysics 597 (2017).

BibTeX: 

Last updated on 2019-20-07 at 07:20