Accession Number : ADA464473
Title : Evidence for Shock Acceleration in the Binary Pulsar System PSR B1259-63
Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC
Personal Author(s) : Grove, J. E. ; Tavani, M. ; Purcell, W. R. ; Johnson, W. N. ; Kurfess, J. D. ; Strockman, M. S. ; Arons, J.
Report Date : 1995
Pagination or Media Count : 10
Abstract : The PSR B1259-63 system (Johnston et al. 1992, 1994) was observed near periastron by the Compton Gamma-Ray Observatory in January 1994. This system contains a rapidly rotating pulsar and a Be star in a highly eccentric binary orbit. We report the discovery by the OSSE instrument of unpulsed emission with a hard power-law spectrum between 50 and 200 keV from the direction of this system. Neither diffuse galactic background emission nor nearby X-ray binaries contribute significant to the detected flux. Our results are particularly important for the theory of interaction of pulsars with gaseous environments. We interpret the hard X-ray emission as synchrotron radiation from relativistic particles of the PSR B1259-63 wind being shocked and accelerated within the binary. Our results indicate, for the first time in a binary pulsar, that shock acceleration can increase the original energy of pulsar wind particles by a factor > but similar to 10, despite the high synchrotron and inverse Compton cooling rates near periastron. The derived shock properties (efficiency, radiation spectrum, timescale) are relevant for a broad class of high-energy astrophysical sources characterized by shocked relativistic plasmas subject to strong radiative cooling.
Descriptors : *HIGH ENERGY , *SYNCHROTRON RADIATION , *COMPTON SCATTERING , EMISSION , REPRINTS , RADIANT COOLING , PULSARS , FLUX DENSITY , INTERACTIONS , X RAYS , GASES
Subject Categories : ASTRONOMY
RADIOFREQUENCY WAVE PROPAGATION
Distribution Statement : APPROVED FOR PUBLIC RELEASE