Open AccessV0332+53 in the outburst of 2004–2005: luminosity dependence of the cyclotron line and pulse profile
Author(s) -
Tsygankov S. S.,
Lutovinov A. A.,
Churazov E. M.,
Sunyaev R. A.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10610.x
Subject(s) - physics , cyclotron , pulsar , luminosity , cyclotron resonance , astrophysics , line (geometry) , harmonics , pulse (music) , scattering , nuclear physics , plasma , optics , geometry , mathematics , quantum mechanics , voltage , galaxy , detector
We present the results of observations of the transient X‐ray pulsar V0332+53 performed during a very powerful outburst, from 2004 December to 2005 February, with the INTEGRAL and RXTE observatories in a wide (3–100 keV) energy band. A cyclotron resonance scattering line at an energy of ∼26 keV has been detected in the source spectrum together with its two higher harmonics at ∼50 and ∼73 keV, respectively. We show that the energy of the line is not constant but changes linearly with the source luminosity. Strong pulse profile variations, especially near the cyclotron line, are revealed for different levels of source intensity. We discuss the obtained results in terms of the theoretical models of X‐ray pulsars.