Kreykenbohm, I., Wilms, J. (Joern), Coburn, W. (Wayne), Kuster, M. (Markus), Rothschild, Richard E., 1943-, Heindl, W. A., Kretschmar, P. and Staubert, R.. (2004) The variable cyclotron line in GX 301-2. Astronomy & Astrophysics, Vol.427 (No.3). pp. 975-986. ISSN 0004-6361

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Abstract

We present pulse phase resolved spectra of the hypergiant high mass X-ray binary GX 301-2. We observed the source in 2001 October with RXTE continuously for a total on-source time of almost 200 ks. We model the continuum with both, a heavily absorbed partial covering model and a reflection model. In either case we find that the well known cyclotron resonant scattering feature (CRSF) at ~35 keV is - although present at all pulse phases - strongly variable over the pulse: the line position varies by 25% from 30 keV in the fall of the secondary pulse to 38 keV in the fall of the main pulse where it is deepest. The line variability implies that we are seeing regions of magnetic field strength varying between G and G.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science > Physics
Library of Congress Subject Headings (LCSH):	Giant stars, X-ray sources, Galactic, Double stars, Cyclotron resonance
Journal or Publication Title:	Astronomy & Astrophysics
Publisher:	EDP Sciences
ISSN:	0004-6361
Date:	December 2004
Volume:	Vol.427
Number:	No.3
Page Range:	pp. 975-986
Identification Number:	10.1051/0004-6361:20035836
Status:	Peer Reviewed
Access rights to Published version:	Open Access
Funder:	Deutsche Forschungsanstalt für Luft- und Raumfahrt (DLR), Deutscher Akademischer Austauschdienst (DAAD), United States. National Aeronautics and Space Administration (NASA), National Science Foundation (U.S.) (NSF)
Grant number:	50OR0002 (DLR), BAS5-10729 (NASA), NAS5-30720 (NASA), NSF-INT-0003773 (NSF)
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URI:	http://wrap.warwick.ac.uk/id/eprint/3797

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