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Title: Very-high energy observations of the galactic center region by VERITAS in 2010-2012

The Galactic center is an interesting region for high-energy (0.1-100 GeV) and very-high-energy (E > 100 GeV) γ-ray observations. Potential sources of GeV/TeV γ-ray emission have been suggested, e.g., the accretion of matter onto the supermassive black hole, cosmic rays from a nearby supernova remnant (e.g., Sgr A East), particle acceleration in a plerion, or the annihilation of dark matter particles. The Galactic center has been detected by EGRET and by Fermi/LAT in the MeV/GeV energy band. At TeV energies, the Galactic center was detected with moderate significance by the CANGAROO and Whipple 10 m telescopes and with high significance by H.E.S.S., MAGIC, and VERITAS. We present the results from three years of VERITAS observations conducted at large zenith angles resulting in a detection of the Galactic center on the level of 18 standard deviations at energies above ∼2.5 TeV. The energy spectrum is derived and is found to be compatible with hadronic, leptonic, and hybrid emission models discussed in the literature. Future, more detailed measurements of the high-energy cutoff and better constraints on the high-energy flux variability will help to refine and/or disentangle the individual models.
Authors:
; ; ; ;  [1] ;  [2] ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ; ; ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] more »; « less
  1. Department of Physics, Washington University, St. Louis, MO 63130 (United States)
  2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  3. Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States)
  4. Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States)
  5. School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)
  6. Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States)
  7. Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)
  8. Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)
  9. Institute of Physics and Astronomy, University of Potsdam, D-14476 Potsdam-Golm (Germany)
  10. Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States)
  11. School of Physics, National University of Ireland Galway, University Road, Galway (Ireland)
  12. Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 (United States)
  13. School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
Publication Date:
OSTI Identifier:
22365466
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 790; 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; ACCELERATION; ANNIHILATION; BLACK HOLES; COSMIC RADIATION; DATA ANALYSIS; DETECTION; EMISSION; ENERGY SPECTRA; GALAXIES; GAMMA RADIATION; GEV RANGE; HADRONS; MEV RANGE; NONLUMINOUS MATTER; SUPERNOVA REMNANTS; TELESCOPES; TEV RANGE