DISCOVERY OF A NEW TeV GAMMA-RAY SOURCE: VER J0521+211

Journal Article · Sun Oct 20 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/776/2/69· OSTI ID:22270753

Archambault, S. ^[1]; Arlen, T.; Aune, T. ^[2]; Behera, B.; Federici, S. ^[3]; Beilicke, M.; Buckley, J. H.; Bugaev, V. ^[4]; Benbow, W. ^[5]; Bird, R. ^[6]; Bouvier, A. ^[7]; Byrum, K. ^[8]; Cesarini, A.; Connolly, M. P. ^[9]; Ciupik, L. ^[10]; Cui, W.; Feng, Q.; Finley, J. P. ^[11]; Errando, M. ^[12]; others, and

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1. Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada)
2. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)
3. DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
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. Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)
9. School of Physics, National University of Ireland Galway, University Road, Galway (Ireland)
10. Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States)
11. Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)
12. Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States)

We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov Telescope Array. These observations were motivated by the discovery of a cluster of >30 GeV photons in the first year of Fermi Large Area Telescope observations. VER J0521+211 is relatively bright at TeV energies, with a mean photon flux of (1.93 ± 0.13{sub stat} ± 0.78{sub sys}) × 10{sup –11} cm{sup –2} s{sup –1} above 0.2 TeV during the period of the VERITAS observations. The source is strongly variable on a daily timescale across all wavebands, from optical to TeV, with a peak flux corresponding to ∼0.3 times the steady Crab Nebula flux at TeV energies. Follow-up observations in the optical and X-ray bands classify the newly discovered TeV source as a BL Lac-type blazar with uncertain redshift, although recent measurements suggest z = 0.108. VER J0521+211 exhibits all the defining properties of blazars in radio, optical, X-ray, and gamma-ray wavelengths.

• OSTI ID: 22270753
• Journal Information: Astrophysical Journal, Vol. 776, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
BL LACERTAE OBJECTS
BLACK HOLES
CHERENKOV COUNTERS
COSMIC GAMMA SOURCES
CRAB NEBULA
GALAXIES
GAMMA ASTRONOMY
GEV RANGE
QUASARS
RED SHIFT
TELESCOPE COUNTERS
TEV RANGE
X RADIATION