A Radio Pulsar Search of the Gamma-ray Binaries LS I +61 303 and LS 5039

Abstract

LS I +61 303 and LS 5039 are exceptionally rare examples of HMXBs with MeV-TeV emission, making them two of only five known or proposed "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 4.1-14.5 uJy, 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.

ApJ, in press

References in corpus (16)

• Mass loss from hot massive stars
• Catalogue of high-mass X-ray binaries in the Galaxy ($4^{th}$ edition)
• Gamma-ray binaries: pulsars in disguise ?
• Modeling interaction of relativistic and nonrelativistic winds in binary system PSR 1259-63/SS2883. I.Hydrodynamical limit
• Accretion vs colliding wind models for the gamma-ray binary LS I +61 303: an assessment
• Global X-ray properties of the O and B stars in Carina
• Discovery of a point-like very-high-energy gamma-ray source in Monoceros
• Orbital X-Ray Variability of the Microquasar LS 5039
• Confirmation of persistent radio jets in the microquasar LS 5039
• INTEGRAL and XMM-Newton observations of LSI +61 303
• Joint H-alpha and X-Ray Observations of Massive X-Ray Binaries. II. The Be X-ray Binary and Microquasar LS I +61 303
• The gamma-ray binary LS 5039: mass and orbit constraints from MOST observations
• Exploring the connection between the stellar wind and the non-thermal emission in LS 5039
• The B and Be Star Population of NGC 3766
• H-alpha Emission Variability in the gamma-ray Binary LS I +61 303
• Modeling the Wind of the Be Star SS 2883

Cited by in corpus (19)

• Gamma-ray binaries and related systems
• On the binary nature of the gamma-ray sources AGL J2241+4454 (=MWC 656) and HESS J0632+057 (=MWC 148)
• Large-scale flow dynamics and radiation in pulsar gamma-ray binaries
• Sign of hard X-ray pulsation from the gamma-ray binary system LS 5039
• Periodic morphological changes in the radio structure of the gamma-ray binary LS 5039
• Physical properties of the gamma-ray binary LS 5039 through low and high frequency radio observations
• Possible changes of state and relevant timescales for a neutron star in LS I +61°303
• Estimating the contribution of Galactic sources to the diffuse neutrino flux
• On the origin of LS 5039 and PSR J1825-1446
• H-alpha observations of the gamma-ray-emitting Be/X-ray binary LSI+61303: orbital modulation, disk truncation, and long-term variability
• Search for radio pulsations in LS I +61 303
• Radio absorption in high-mass gamma-ray binaries
• Impact of the orbital uncertainties on the timing of pulsars in binary systems
• Multiwavelength Observations of The TeV Binary LS I +61 303 with VERITAS, Fermi-LAT and Swift-XRT During a TeV Outburst
• Modelling the correlated keV/TeV light curves of Be/gamma-ray binaries
• Orbital and superorbital variability of LS I +61 303 at low radio frequencies with GMRT and LOFAR
• Tracing colliding winds in the UV line orbital variability of gamma-ray binaries
• Low frequency radio spectrum of LS 5039 during periastron and apastron passages
• Spectral lags of flaring events in $LSI+61^o$ 303 from RXTE Observations