Author/Authors :
Katja Pottschmidt، نويسنده , , Ingo Kreykenbohm، نويسنده , , Jorn Wilms، نويسنده , , Wayne Coburn، نويسنده , , Richard E. Rothschild، نويسنده , , Peter Kretschmar، نويسنده , , Vanessa McBride، نويسنده , , Slawomir Suchy، نويسنده , , Rudiger Staubert، نويسنده ,
Abstract :
We present an analysis of the 2-150 keV spectrum of the transient X-ray pulsar V0332+53 taken with the Rossi X-Ray Timing Explorer (RXTE) in 2004 December. We report on the detection of three cyclotron resonance features at 27, 51, and 74 keV in the phase-averaged data, corresponding to a polar magnetic field of 2.7 * 1012 G. After 4U 0115+63, this makes V0332+53 the second accreting neutron star in which more than two cyclotron lines have been detected; this has now also been confirmed by INTEGRAL. Pulse-phase spectroscopy reveals remarkably little variability of the cyclotron line through the 4.4 s X-ray pulse.
