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

D. Klochkov; D. Horns; A. Santangelo; R. Staubert; A. Segreto; C. Ferrigno; P. Kretschmar; I. Kreykenbohm; A. La Barbera; N. Masetti; M. McCollough; K. Pottschmidt; G. Schoenherr; J. Wilms

doi:10.1051/0004-6361:20066801

arXiv · astro-ph/0701791

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

D. Klochkov·D. Horns·A. Santangelo·R. Staubert·A. Segreto·C. Ferrigno·P. Kretschmar·I. Kreykenbohm·A. La Barbera·N. Masetti·M. McCollough·K. Pottschmidt·G. Schoenherr·J. Wilms

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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 Swift. The pulse period P and its temporal derivative P_dot 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 P_dot 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 ~26 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.

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D. Klochkov, D. Horns, A. Santangelo, R. Staubert, A. Segreto, C. Ferrigno, P. Kretschmar, I. Kreykenbohm, A. La Barbera, N. Masetti, M. McCollough, K. Pottschmidt, G. Schoenherr, J. Wilms. 2007-01-27. INTEGRAL and Swift observations of EXO 2030+375 during a giant outburst. https://doi.org/10.1051/0004-6361%3A20066801

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