Gamma-ray emission states in the redback millisecond pulsar binary system PSR J1227-4853

Abstract

Long expected transition states between the rotation powered and accretion powered non-thermal emission in the millisecond pulsar binary systems have been recently observed in the case of three objects PSR J1023+0038, PSR J1824-2452, and PSR J1227-4859. Surprisingly, the transition is related to the significant change in the $\gamma$-ray flux being a factor of a few higher with the presence of an accretion disk. The origin of this enhanced emission seems to be related to the penetration of the inner pulsar magnetosphere by the accretion disk. We propose that the radiation processes, characteristic for the rotation powered pulsar, can co-exist with the presence of an accretion disk in the inner pulsar magnetosphere. In our scenario additional $\gamma$-ray emission is produced by secondary leptons, originated close to the acceleration gap, which Compton up-scatter thermal radiation from the accretion disk to GeV energies. The accretion disk penetrates deep into the pulsar magnetosphere allowing the matter to fall onto the NS surface producing pulsed X-ray emission. We show that the sum of the rotation powered pulsar $\gamma$-ray emission, produced by the primary electrons in the curvature process, and the $\gamma$-ray emission, produced by secondary leptons, can explain the observed high energy radiation from the redback binary pulsar PSR J1227-4853 in the state with evidences of the accretion disk.

12 pages, 3 figures, MNRAS Lett., accepted

References in corpus (7)

• Discovery of PSR J1227-4853: A transition from a low-mass X-ray binary to a redback millisecond pulsar
• X-ray coherent pulsations during a sub-luminous accretion disk state of the transitional millisecond pulsar XSS J12270-4859
• Identification of the High-Energy Gamma-Ray Source 3FGL J1544.6-1125 as a Transitional Millisecond Pulsar Binary in an Accreting State
• Discovery of Gamma-ray Pulsations from the Transitional Redback PSR J1227-4853
• Fermi Observation of the transitional pulsar binary XSS J12270-4859
• Accretion-powered pulsations in an apparently quiescent neutron star binary
• Coordinated X-ray, Ultraviolet, Optical, and Radio Observations of the PSR J1023+0038 System in a Low-mass X-ray Binary State

Cited by in corpus (1)

• High energy signatures of quasi-spherical accretion onto rotating, magnetized neutron star in the ejector-accretor intermediate state