Pulse profiles and cyclotron line energy dependence on X-ray pulsars   luminosity
  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. 
S. Tsygankov (1), A. Lutovinov (1), E. Churazov (1 and 2), R. Sunyaev   (1 and 2) ((1) Space Research Institute, Moscow, Rus...