title   
  

Is the lack of pulsations in low mass X-Ray binaries due to comptonizing coronae?

Göğüş, Ersin and Alpar, M. Ali and Gilfanov, Marat (2007) Is the lack of pulsations in low mass X-Ray binaries due to comptonizing coronae? The Astrophysical journal, 659 (1). pp. 580-584. ISSN 0004-637X

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Official URL: http://dx.doi.org/10.1086/512028

Abstract

The spin periods of the neutron stars in most Low Mass X-ray Binary (LMXB) systems still remain undetected. One of the models to explain the absence of coherent pulsations has been the suppression of the beamed signal by Compton scattering of X-ray photons by electrons in a surrounding corona. We point out that simultaneously with wiping out the pulsation signal, such a corona will upscatter (pulsating or not) X-ray emission originating at and/or near the surface of the neutron star leading to appearance of a hard tail of Comptonized radiation in the source spectrum. We analyze the hard X-ray spectra of a selected set of LMXBs and demonstrate that the optical depth of the corona is not likely to be large enough to cause the pulsations to disappear.

Item Type:Article
Uncontrolled Keywords:accretion, accretion disks; stars : individual (GX 9+1), (GX 9+9), (Sco X-1); stars : neutron; X-rays : binaries
Subjects:Q Science > QC Physics
ID Code:273
Deposited By:Ersin Göğüş
Deposited On:20 Mar 2007 02:00
Last Modified:25 May 2011 14:04

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