Multi-wavelength observations of the binary system PSR B1259-63/LS 2883 around the 2014 periastron passage
Krivonos, R.; Tsygankov, S.; Tomsick, J. A.; Zhang, S.; Buckley, D. A. H.; Kretschmar, P.; Babyk, Iu.; Wood, K.; Li, J.; van Soelen, B.; McSwain, M. V.; Chernyakova, M.; Koen, C.; Callanan, P.; Malyshev, D.; Neronov, A.; Vovk, Ie.; O'Shaughnessy, L.; Torres, D.
Ireland, Switzerland, South Africa, Ukraine, Finland, Germany, United States, Russia, Spain, China
Abstract
We report on the results of the extensive multi-wavelength campaign from optical to GeV γ-rays of the 2014 periastron passage of PSR B1259-63, which is a unique high-mass γ-ray emitting binary system with a young pulsar companion. Observations demonstrate the stable nature of the post-periastron GeV flare and prove the coincidence of the flare with the start of rapid decay of the Hα equivalent width, usually interpreted as a disruption of the Be stellar disc. Intensive X-ray observations reveal changes in the X-ray spectral behaviour happening at the moment of the GeV flare. We demonstrate that these changes can be naturally explained as a result of synchrotron cooling of monoenergetic relativistic electrons injected into the system during the GeV flare.