Issue |
A&A
Volume 464, Number 3, March IV 2007
|
|
---|---|---|
Page(s) | L45 - L48 | |
Section | Letters | |
DOI | https://doi.org/10.1051/0004-6361:20066801 | |
Published online | 29 January 2007 |
Letter to the Editor
INTEGRAL and Swift observations of EXO 2030+375 during a giant outburst*
1
Institut für Astronomie und Astrophysik, University of Tübingen, Sand 1, 72076 Tübingen, Germany e-mail: klochkov@astro.uni-tuebingen.de
2
INAF IFC-Pa, via U. La Malfa 153, 90146 Palermo, Italy
3
Integral SOC ESA, Madrid, Spain
4
INTEGRAL Science Data Centre, Chemin d'Écogia, 16, 1290, Versoix, Switzerland
5
INAF IASF-Bo, via Gobetti 101, 40129 Bologna, Italy
6
Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138, USA
7
Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92093-0424, USA
8
Dr. Karl Remeis-Sternwarte, Astronomisches Institut, Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
Received:
23
November
2006
Accepted:
26
January
2007
Aims.We investigate the X-ray spectral and timing properties of the high mass X-ray binary EXO 2030+375 observed during its June–September 2006 giant (type II) outburst.
Methods.The data analyzed in this work are
from partly simultaneous observations with INTEGRAL
and Swift.
The pulse period P and its temporal derivative are
measured. X-ray pulse profiles in different energy ranges and time
intervals are constructed. Pulse averaged X-ray spectra for different
time intervals are studied.
Results.We report a strong spin-up of the source during the
outburst, comparable to that observed in 1985 during the previous
giant outburst when the source was discovered.
The value of is found to be linearly related to the X-ray luminosity
of the source during the outburst.
For the first time the hard X-ray (>25 keV) characteristics of
the source during a type II outburst are studied.
The X-ray pulse profiles apparently change with luminosity.
The X-ray spectral continuum in the 3–120 keV energy range is modeled with an
absorbed power law with an exponential cutoff around
keV.
An iron emission line at ~6–7 keV is observed.
The spectrum reveals some features between 10 and 20 keV which
can be modeled either by a broad emission line at ~13–15 keV
(a “bump”) or by two absorption lines at ~10 and ~20 keV.
Key words: X-ray binaries / stars: neutron / accretion, accretion disks
© ESO, 2007
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