Cyclotron resonant scattering feature simulations: I. Thermally averaged cyclotron scattering cross sections, mean free photonpath 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, SokolovaLapa E, Klochkov D, Ferrigno C, Fuerst F, Hemphill PF, MarcuCheatham DM, Dauser T, Wilms J
Journal: → Astronomy & Astrophysics 
Publisher: EDP Sciences
Publication year: 2017
Volume: 597
ISSN: 14320746
Language: English
Abstract
Context. Electron cyclotron resonant scattering features (CRSFs) are observed as absorptionlike lines in the spectra of Xray 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 Xray 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
   Dr.KarlRemeisSternwarte Bamberg, Astronomisches Institut 

   Professur für Astronomie und Astrophysik 

   Dr.KarlRemeisSternwarte Bamberg, Astronomisches Institut 

   Professur für Astronomie und Astrophysik 

   Professur für Astronomie und Astrophysik 

   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 photonpath tables, and electron momentum sampling. Astronomy & Astrophysics, 597. https://dx.doi.org/10.1051/00046361/201629352 
MLA:  Schwarm, FritzWalter, et al. "Cyclotron resonant scattering feature simulations: I. Thermally averaged cyclotron scattering cross sections, mean free photonpath tables, and electron momentum sampling." Astronomy & Astrophysics 597 (2017). 