We present the results of broad band (3-100 keV) observations of several X-ray pulsars with the INTEGRAL and RXTE observatories. We concentrate on the luminosity and energy dependence of the pulse profile and the variations of the cyclotron line energy. In V0332+53 the line energy changes nearly linearly with the source luminosity, while in 4U0115+63 its behavior is more complicated. Strong variations of the pulse profile with the energy and source intensity were found for both of pulsars; in V0332+53 the changes of the pulse profile near the cyclotron line are especially drastic. The preliminary results obtained for Her X-1 and GX 301-2 in a high intensity state show the absence of significant pulse profile changes with the energy. Results and possible emission mechanisms are briefly discussed in terms of theoretical models of accreting pulsars.
@article{arxiv.astro-ph/0610476,
title = {Pulse profiles and cyclotron line energy dependence on X-ray pulsars luminosity},
author = {S. Tsygankov and A. Lutovinov and E. Churazov and R. Sunyaev},
journal= {arXiv preprint arXiv:astro-ph/0610476},
year = {2007}
}
Comments
5 pages, submitted proceeding of the 6th INTEGRAL Workshop "The Obscured Universe" July 2-8, 2006 Space Research Institute Moscow, Russia