High-energy Observations of PSR B1259-63/LS 2883 through the 2014 Periastron Passage: Connecting X-Rays to the GeV Flare
Abstract
The binary system PSR B1259-63/LS 2883 is well sampled in radio, X-rays, and TeV γ-rays, and shows orbital-phase-dependent variability in these frequencies. The first detection of GeV γ-rays from the system was made around the 2010 periastron passage. In this Letter, we present an analysis of X-ray and γ-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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2015
- DOI:
- 10.1088/2041-8205/798/1/L26
- arXiv:
- arXiv:1412.2483
- Bibcode:
- 2015ApJ...798L..26T
- Keywords:
-
- gamma rays: stars;
- pulsars: individual: PSR B1259–63;
- X-rays: binaries;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 16 pages, 3 figures, 2 tables, ApJ Letters, in press