Bibcode
Caballero-García, M. D.; Camero-Arranz, A.; Özbey Arabacı, M.; Zurita, C.; Suso, J.; Gutiérrez-Soto, J.; Beklen, E.; Kiaeerad, F.; Garrido, R.; Hudec, R.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 589, id.A9, 12 pp.
Advertised on:
4
2016
Revista
Número de citas
15
Número de citas referidas
14
Descripción
Aims: We present a study of the Be/X-ray binary system V 0332+53
with the main goal of characterizing its behaviour mainly during the
intermediate-luminosity X-ray event in 2008. In addition, we aim to
contribute to the understanding of the behaviour of the donor companion
by including optical data from our dedicated campaign starting in 2006.
Methods: V 0332+53 was observed by RXTE and Swift during the
decay of the intermediate-luminosity X-ray outburst of 2008, and with
Suzaku before the rising of the third normal outburst of the 2010
series. In addition, we present recent data from the Spanish
ground-based astronomical observatories of El Teide (Tenerife), Roque de
los Muchachos (La Palma), and Sierra Nevada (Granada), and since 2006
from the Turkish TÜBİTAK National Observatory (Antalya). We
have performed temporal analyses to investigate the transient behaviour
of this system during several outbursts. Results: Our optical
study revealed that continuous mass ejection episodes from the Be star
have been taking place since 2006 and another is currently ongoing. The
broad-band 1-60 keV X-ray spectrum of the neutron star during the decay
of the 2008 outburst was well fitted with standard phenomenological
models that were enhanced by an absorption feature of unknown origin at
about 10 keV and a narrow iron K-alpha fluorescence line at 6.4 keV. For
the first time in V 0332+53 we tentatively see an increase in the
cyclotron line energy with increasing flux (although further and more
sensitive observations are needed to confirm this). The fast aperiodic
variability shows a quasi-periodic oscillation (QPO) at 227 ± 9
mHz only during the lowest luminosities, which might indicate that the
inner regions surrounding the magnetosphere are more visible during the
lowest flux states.