Modelling the light curves of ultraluminous X-ray sources as precession
Dauser T, Middleton M, Wilms J (2017)
Publication Status: Published
Publication Type: Journal article
Publication year: 2017
Journal
Publisher: OXFORD UNIV PRESS
Book Volume: 466
Pages Range: 2236-2241
Journal Issue: 2
Abstract
We present a freely available XSPEC model for the modulations seen in the long-term light curves of multiple ultraluminous X-ray sources (ULXs). By incorporating the physics of multiple electron scatterings (ray traced with a Monte Carlo routine), we go beyond analytical predictions and show that the geometrical beaming of radiation in the conical outflow can be more than a factor of 100 for opening angles smaller than 10 degrees. We apply our new model to the long-term, well-sampled Swift light curve of the recently confirmed ULX pulsar NGC 5907 X-1 with an established period of 78 d. Our results suggest that geometrical beaming together with a slight precession of the conical wind can describe the light curve with a consistent set of parameters for the wind. The small opening angle of roughly 10 degrees-13 degrees implies a highly supercritical flow and boosting factors of the order of B = 60-90 that would yield a fairly low surface magnetic field strength of 2 x 10(10) G.
Authors with CRIS profile
Thomas Dauser
Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut
Jörn Wilms
Professur für Astronomie und Astrophysik
Involved external institutions
United Kingdom (GB)How to cite
APA:
Dauser, T., Middleton, M., & Wilms, J. (2017). Modelling the light curves of ultraluminous X-ray sources as precession. Monthly Notices of the Royal Astronomical Society, 466(2), 2236-2241. https://doi.org/10.1093/mnras/stw3304
MLA:
Dauser, Thomas, M. Middleton, and Jörn Wilms. "Modelling the light curves of ultraluminous X-ray sources as precession." Monthly Notices of the Royal Astronomical Society 466.2 (2017): 2236-2241.
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