A RADIO PULSAR SEARCH OF THE {gamma}-RAY BINARIES LS I +61 303 AND LS 5039

Journal Article · Thu Sep 01 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/738/1/105· OSTI ID:21582859

Virginia McSwain, M ^[1]; Ray, Paul S ^[2]; Ransom, Scott M ^[3]; Roberts, Mallory S. E. ^[4]; Dougherty, Sean M ^[5]

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1. Department of Physics, Lehigh University, 16 Memorial Drive E, Bethlehem, PA 18015 (United States)
2. Space Science Division, Naval Research Laboratory, Code 7655, 4555 Overlook Avenue SW, Washington, DC 20375 (United States)
3. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
4. Eureka Scientific, Inc., 2452 Delmer Street, Suite 100, Oakland, CA 94602-3017 (United States)
5. National Research Council of Canada, Herzberg Institute for Astrophysics, Dominion Radio Astrophysical Observatory, P.O. Box 248, Penticton, British Columbia V2A 6J9 (Canada)

LS I +61 303 and LS 5039 are exceptionally rare examples of high-mass X-ray binaries with MeV-TeV emission, making them two of only five known '{gamma}-ray binaries'. There has been disagreement within the literature over whether these systems are microquasars, with stellar winds accreting onto a compact object to produce high energy emission and relativistic jets, or whether their emission properties might be better explained by a relativistic pulsar wind colliding with the stellar wind. Here we present an attempt to detect radio pulsars in both systems with the Green Bank Telescope. The upper limits of flux density are between 4.1 and 14.5 {mu}Jy, and we discuss the null results of the search. Our spherically symmetric model of the wind of LS 5039 demonstrates that any pulsar emission will be strongly absorbed by the dense wind unless there is an evacuated region formed by a relativistic colliding wind shock. LS I +61 303 contains a rapidly rotating Be star whose wind is concentrated near the stellar equator. As long as the pulsar is not eclipsed by the circumstellar disk or viewed through the densest wind regions, detecting pulsed emission may be possible during part of the orbit.

• OSTI ID: 21582859
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 738; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
EMISSION
EVOLUTION
FLUX DENSITY
GAMMA RADIATION
IONIZING RADIATIONS
PULSARS
RADIATIONS
STAR ACCRETION
STAR EVOLUTION
STELLAR ACTIVITY
STELLAR WINDS