INTEGRAL observation of the high-mass X-ray transient V 0332+53 during the 2005 outburst decline
UNSPECIFIED. (2006) INTEGRAL observation of the high-mass X-ray transient V 0332+53 during the 2005 outburst decline. ASTRONOMY & ASTROPHYSICS, 451 (1). pp. 187-194. ISSN 0004-6361Full text not available from this repository.
Official URL: http://dx.doi.org/10.1051/0004-6361:20054235
The decline of the high mass X-ray transient V0332+53 during the Dec. 2004 to Feb. 2005 outburst is analysed from the data recorded by INTEGRAL. The flux is shown to decrease exponentially until 2005 Feb. 10, with a decay time scale of similar to 30 days above 20 keV and similar to 20 days at lower energies, and to decrease linearly thereafter. The energy spectrum is well modelled throughout the decay by a power law with a folding energy of similar to 7.5 keV, and with two cyclotron absorption features. The folding energy does not vary significantly over the decay, but the spectrum becomes harder with time. Most importantly, we show that the parameters describing the fundamental cyclotron line around 27 keV do vary with time: its energy and depth increase (by about 17% for the energy in similar to 6 weeks), while its width decreases. These changes of the cyclotron line parameters are interpreted as resulting from a change in the extent of the cyclotron scattering region. Two quasi-periodic oscillations are also observed at various times during the observations, one at 0.05 Hz and another one near the pulsation frequency around 0.23 dHz.
|Item Type:||Journal Article|
|Subjects:||Q Science > QB Astronomy|
|Journal or Publication Title:||ASTRONOMY & ASTROPHYSICS|
|Publisher:||EDP SCIENCES S A|
|Official Date:||May 2006|
|Number of Pages:||8|
|Page Range:||pp. 187-194|
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