Broad-band Spectral Properties of Accreting X-ray Binary Pulsars

Abstract

Broad-band spectra of accreting X-ray binary pulsars can be fit by a phenomenological model composed by a power law with a high energy rollover above 10 keV, plus a blackbody component with a temperature of few hundred eV. While, at least qualitatively, the hard tail can be explained in terms of (inverse) Compton scattering, the origin of the soft component cannot find a unique explanation. Recently a qualitative picture able to explain the overall broad band-spectrum of luminous X-ray pulsars was carried out by taking into account the effect of bulk Comptonization in the accretion column. After a review on these recent theoretical developments, I will present a case study of how different modelization of the continuum affect broad features, in particular the cyclotron resonance features in Vela X-1.

8 pages, 3 figures; to appear in the Proceedings of COSPAR Colloquium "Spectra & Timing of Compact X-ray Binaries," January 17-20, 2005, Mumbai, India

References in corpus (5)

• Origin of the Soft Excess in X-ray Pulsars
• Hard Spectra of X-Ray Pulsars from INTEGRAL Data
• Spectral Formation in X-Ray Pulsars: Bulk Comptonization in the Accretion Shock
• Spectral Formation in X-Ray Pulsar Accretion Columns
• A Hard X-ray View of Accreting X-ray Binary Pulsars

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• The accretion environment in Vela X-1 during a flaring period using XMM-Newton
• IGRJ18179-1621: An obscured X-ray pulsar discovered by INTEGRAL
• The X-ray Transient 2XMMi J003833.3+402133: A Candidate Magnetar at High Galactic Latitude