EVIDENCE FOR LONG-TERM GAMMA-RAY AND X-RAY VARIABILITY FROM THE UNIDENTIFIED TeV SOURCE HESS J0632+057


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Acciari V. A., Aliu E., Arlen T., Beilicke M., Benbow W., Boltuch D., ...Daha Fazla

ASTROPHYSICAL JOURNAL LETTERS, cilt.698, sa.2, 2009 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 698 Sayı: 2
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1088/0004-637x/698/2/l94
  • Dergi Adı: ASTROPHYSICAL JOURNAL LETTERS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: acceleration of particles, binaries: general, gamma rays: observations, stars: individual (HESS J0632+057, MWC 148), DISCOVERY, EMISSION
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

HESS J0632+057 is one of only two unidentified very-high-energy gamma-ray sources which appear to be point-like within experimental resolution. It is possibly associated with the massive Be star MWC 148 and has been suggested to resemble known TeV binary systems like LS I + 61 303 or LS 5039. HESS J0632+057 was observed by VERITAS for 31 hr in 2006, 2008, and 2009. During these observations, no significant signal in gamma rays with energies above 1 TeV was detected from the direction of HESS J0632+057. A flux upper limit corresponding to 1.1% of the flux of the Crab Nebula has been derived from the VERITAS data. The nondetection by VERITAS excludes with a probability of 99.993% that HESS J0632+057 is a steady gamma-ray emitter. Contemporaneous X-ray observations with the Swift X-Ray Telescope reveal a factor of 1.8 +/- 0.4 higher flux in the 1-10 keV range than earlier X-ray observations of HESS J0632+057. The variability in the gamma-ray and X-ray fluxes supports interpretation of the object as a gamma-ray emitting binary.