Modulated Gamma-ray emission from compact millisecond pulsar binary systems

Abstract

A significant amount of the millisecond pulsars has been discovered within binary systems. In several such binary systems the masses of the companion stars have been derived allowing to distinguish two classes of objects, called the Black Widow and the Redback binaries. Pulsars in these binary systems are expected to produce winds which, colliding with stellar winds, create conditions for acceleration of electrons. These electrons should interact with the anisotropic radiation from the companion stars producing gamma-ray emission modulated with the orbital period of the binary system. We consider the interaction of a millisecond pulsar (MSP) wind with a very inhomogeneous stellar wind from the companion star within binary systems of the Black Widow and Redback types. It is expected that the pulsar wind should mix efficiently with the inhomogeneous stellar wind. Electrons accelerated in such mixed, turbulent winds can interact with the magnetic field and also strong radiation from the companion star producing not only synchrotron radiation but also gamma-rays in the the Inverse Compton process. Applying numerical methods, we calculated the GeV-TeV gamma-ray spectra and the light curves expected from some millisecond pulsar binary systems. It is concluded that energetic millisecond pulsar binary systems create a new class of TeV gamma-ray sources which could be detectable by the future Cherenkov arrays (e.g. CTA) and possibly also by the extensive campaigns with the present arrays (HESS, MAGIC, VERITAS). However, gamma-ray emission from the millisecond pulsar binary systems is predicted to have different features than those observed in the case of massive TeV gamma-ray binaries such as LS I 303 61 or LS 5039. The maximum in the TeV gamma-ray orbital light curve should appear when the MSP is behind the companion star.

10 pages, 4 figures, 1 table, accepted to Astronomy and Astrophysics

References in corpus (10)

• The ATNF Pulsar Catalogue
• The Second Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• A Radio Pulsar/X-ray Binary Link
• Gamma-ray binaries: pulsars in disguise ?
• Energy dependent gamma-ray morphology in the Pulsar wind nebula HESSJ1825-137
• Discovery of High-Energy Gamma-Ray Emission from the Binary System PSR B1259-63/LS 2883 Around Periastron with Fermi
• X-ray Variability and Evidence for Pulsations from the Unique Radio Pulsar/X-ray Binary Transition Object FIRST J102347.6+003841
• Periodic very high energy gamma-ray emission from LS I +61 303 observed with the MAGIC telescope
• Propagation of very high energy gamma-rays inside massive binaries LS 5039 and LSI +61 303
• The light curve of the companion to PSR B1957+20

Cited by in corpus (12)

• Constraining Relativistic Bow Shock Properties in Rotation-Powered Millisecond Pulsar Binaries
• X-ray Through Very-High-Energy Intrabinary Shock Emission from Black Widows and Redbacks
• Signatures of Intra-binary shock emission in the black widow pulsar binary PSR J2241-5236
• Fermi Observation of the transitional pulsar binary XSS J12270-4859
• Discovery of Gamma-Ray Orbital Modulation in the Black Widow PSR J1311-3430
• The peculiar chemical abundance of the transitional millisecond pulsar PSR J1023+0038 -- Li enhancement
• Fermi Variability Study of the Candidate Pulsar Binary 2FGL~J0523.3-2530
• On the vanishing orbital X-ray variability of the eclipsing binary millisecond pulsar 47 Tuc W
• Observation of the Black Widow B1957+20 millisecond pulsar binary system with the MAGIC telescopes
• Gamma-rays from the binary system containing PSR J2032+4127 during its periastron passage
• High Energy Emission from Black Widows and Redbacks
• Gamma-Ray Millisecond Pulsars: Off-pulse Emission Characteristics, Phase-Resolved Pseudo-Luminosity--Cutoff Energy Correlation, and High-energy Pulsed Emission