Published by
EDP Sciences
EDP Sciences Journals List
Subscriber Authentication Point
Home All issues Volume 464/ 3 Article
Free access
Issue A&A
Volume 464, Number 3, March IV 2007
Page(s) L45 - L48
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20066801



A&A 464, L45-L48 (2007)
DOI: 10.1051/0004-6361:20066801

Letter

INTEGRAL and Swift observations of EXO 2030+375 during a giant outburst

D. Klochkov1, D. Horns1, A. Santangelo1, R. Staubert1, A. Segreto2, C. Ferrigno2, P. Kretschmar3, I. Kreykenbohm1, 4, A. La Barbera2, N. Masetti5, M. McCollough6, K. Pottschmidt7, G. Schönherr1, and J. Wilms8

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 )

Abstract
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 $\dot P$ 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 $\dot P$ 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 $E\sim26$ 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

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.