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The ASCA X-Ray Spectrum of the Unusual Binary LSI +61°303

Leahy, D. A. and Harrison, Fiona A. and Yoshida, A. (1997) The ASCA X-Ray Spectrum of the Unusual Binary LSI +61°303. Astrophysical Journal, 475 (1). pp. 823-828. ISSN 0004-637X.

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The unusual Be binary LSI +61°303 was observed by the ASCA X-ray satellite twice during the 26 day orbital-outburst cycle. Here we present the results of the spectral analysis of the ASCA data. The emission spectrum can be characterized by an absorbed power law and is inconsistent with other single component models such as blackbody or hot plasma emission. The data show both flux and spectral variability between the two observations. The column density is determined for LSI 61°303 , and we put upper limits on Fe line emission and Fe absorption edge optical depth. The power-law index is similar to that seen for classical X-ray pulsars ; however, the low X-ray luminosity and the power-law emission in other wavebands indicate that the emission is not from an optically thick accretion column but rather synchrotron or inverse-Compton emission from relativistic particles. We argue that the sub-eV emission is synchrotron, the super-eV emission is inverse Compton and that the magnetic field in the emission region is a few hundred gauss.

Item Type:Article
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Harrison, Fiona A.0000-0003-2992-8024
Additional Information:© 1997 The American Astronomical Society. D. A. L. acknowledges support from the Natural Sciences and Engineering Research Council. F. A. H. acknowledges support from a Robert A. Millikan Research Fellowship.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Robert A. Millikan FellowshipUNSPECIFIED
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Space Radiation Laboratory1997-42
Issue or Number:1
Record Number:CaltechAUTHORS:20141202-144057199
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:52291
Deposited By: Deborah Miles
Deposited On:03 Dec 2014 01:14
Last Modified:03 Oct 2019 07:41

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