Papers

Peer-reviewed
Jun, 2016

SUZAKU OBSERVATION OF THE HIGH-INCLINATION BINARY EXO 0748-676 IN THE HARD STATE

ASTROPHYSICAL JOURNAL
  • Zhongli Zhang
  • ,
  • Soki Sakurai
  • ,
  • Kazuo Makishima
  • ,
  • Kazuhiro Nakazawa
  • ,
  • Ko Ono
  • ,
  • Shin'ya Yamada
  • ,
  • Haiguang Xu

Volume
823
Number
2
First page
131
Last page
Language
English
Publishing type
Research paper (scientific journal)
DOI
10.3847/0004-637X/823/2/131
Publisher
IOP PUBLISHING LTD

Utilizing archived Suzaku data acquired on 2007 December 25 for 46 ks, the X-ray spectroscopic properties of the dipping and eclipsing low-mass X-ray binary EXO 0748-676 were studied. At an assumed distance of 7.1 kpc, the data provided a persistent unabsorbed luminosity of 3.4 x 10(36) erg cm(-2) s(-1) in 0.6-55 keV. The source was in a relatively bright low/hard state, wherein the 0.6-55 keV spectrum can be successfully explained by a "double-seed" Comptonization model incorporating a common corona with an electron temperature of similar to 13 keV. The seed photons are thought to be supplied from both the neutron star surface and a cooler truncated disk. Compared to a sample of non-dipping, low-mass X-ray binaries in the low/hard state, the spectrum is subject to stronger Comptonization with a relatively larger Comptonizing y-parameter of similar to 1.4 and a larger coronal optical depth of similar to 5. This result, when attributed to the high inclination of EXO 0748-676, suggests that the Comptonizing corona may elongate along the disk plane and provide a longer path for the seed photons when viewed from edge-on inclinations.

Link information
DOI
https://doi.org/10.3847/0004-637X/823/2/131
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000377410000062&DestApp=WOS_CPL
URL
https://ui.adsabs.harvard.edu/#abs/2016ApJ...823..131Z
ID information
  • DOI : 10.3847/0004-637X/823/2/131
  • ISSN : 0004-637X
  • eISSN : 1538-4357
  • Web of Science ID : WOS:000377410000062

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