skip to main content

Title: Long term observations of B2 1215+30 with veritas

We report on VERITAS observations of the BL Lac object B2 1215+30 between 2008 and 2012. During this period, the source was detected at very high energies (VHEs; E > 100 GeV) by VERITAS with a significance of 8.9σ and showed clear variability on timescales larger than months. In 2011, the source was found to be in a relatively bright state and a power-law fit to the differential photon spectrum yields a spectral index of 3.6 ± 0.4{sub stat} ± 0.3{sub syst} with an integral flux above 200 GeV of (8.0 ± 0.9{sub stat} ± 3.2{sub syst}) × 10{sup –12} cm{sup –2} s{sup –1}. No short term variability could be detected during the bright state in 2011. Multi-wavelength data were obtained contemporaneously with the VERITAS observations in 2011 and cover optical (Super-LOTIS, MDM, Swift/UVOT), X-ray (Swift/XRT), and gamma-ray (Fermi-LAT) frequencies. These were used to construct the spectral energy distribution (SED) of B2 1215+30. A one-zone leptonic model is used to model the blazar emission and the results are compared to those of MAGIC from early 2011 and other VERITAS-detected blazars. The SED can be reproduced well with model parameters typical for VHE-detected BL Lac objects.
Authors:
;  [1] ;  [2] ; ;  [3] ; ; ;  [4] ;  [5] ;  [6] ;  [7] ; ;  [8] ;  [9] ; ; ;  [10] ;  [11] ;  [12] ;  [13] more »; ; « less
  1. Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States)
  2. Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada)
  3. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)
  4. Department of Physics, Washington University, St. Louis, MO 63130 (United States)
  5. Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States)
  6. School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)
  7. Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States)
  8. School of Physics, National University of Ireland Galway, University Road, Galway (Ireland)
  9. Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States)
  10. Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)
  11. School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
  12. Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States)
  13. DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
Publication Date:
OSTI Identifier:
22348475
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 779; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BL LACERTAE OBJECTS; COMPARATIVE EVALUATIONS; EMISSION; ENERGY SPECTRA; GAMMA RADIATION; GEV RANGE; PHOTONS; WAVELENGTHS; X RADIATION