HIGH-ENERGY OBSERVATIONS OF PSR B1259-63/LS 2883 THROUGH THE 2014 PERIASTRON PASSAGE: CONNECTING X-RAYS TO THE GeV FLARE

• Published in: Astrophysical journal. Letters Vol. 798; no. 1; p. L26
• Main Authors: Tam, P H T, Li, K L, Takata, J, Okazaki, A T, Hui, C Y, Kong, A K H
• Format: Journal Article
• Language: English
• Published: United States 01.01.2015
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BINARY STARS; Broadband; COSMIC PHOTONS; DETECTION; ENERGY SPECTRA; Flares; Flux; GAMMA RADIATION; GEV RANGE; Joining; KEV RANGE; PULSARS; Spectra; STELLAR WINDS; Synchrotron radiation; TELESCOPES; TEV RANGE; X RADIATION; X-rays
• ISSN: 2041-8205; 2041-8213
• DOI: 10.1088/2041-8205/798/1/L26

The binary system PSR B1259-63/LS 2883 is well sampled in radio, X-rays, and TeV [gamma]-rays, and shows orbital-phase-dependent variability in these frequencies. The first detection of GeV [gamma]-rays from the system was made around the 2010 periastron passage. In this Letter, we present an analysis of X-ray and [gamma]-ray data obtained by the Swift/XRT, NuSTAR/FPM, and Fermi/LAT, through the recent periastron passage which occurred on 2014 May 4. While PSR B1259-63/LS 2883 was not detected by the Large Area Telescope before and during this passage, we show that the GeV flares occurred at a similar orbital phase as in early 2011, thus establishing the repetitive nature of the post-periastron GeV flares. Multiple flares each lasting for a few days have been observed and short-term variability is seen as well. We also found X-ray flux variation contemporaneous with the GeV flare for the first time. Strong evidence of the keV-to-GeV connection came from the broadband high-energy spectra, which we interpret as synchrotron radiation from the shocked pulsar wind.