VERITAS SEARCH FOR VHE GAMMA-RAY EMISSION FROM DWARF SPHEROIDAL GALAXIES

Journal Article · Fri Sep 10 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/720/2/1174· OSTI ID:21460062

Acciari, V A; Benbow, W ^[1]; Arlen, T ^[2]; Aune, T; Furniss, A ^[3]; Beilicke, M; Buckley, J H; Bugaev, V; Dickherber, R ^[4]; Boltuch, D ^[5]; Bradbury, S M ^[6]; Byrum, K ^[7]; Cannon, A ^[8]; Cesarini, A ^[9]; Christiansen, J L ^[10]; Ciupik, L ^[11]; Cui, W; Finley, J P ^[12]; Duke, C ^[13]; Finnegan, G ^[14]

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1. Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States)
2. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)
3. Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States)
4. Department of Physics, Washington University, St. Louis, MO 63130 (United States)
5. Department of Physics and Astronomy and the Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States)
6. School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT (United Kingdom)
7. Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)
8. School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)
9. School of Physics, National University of Ireland Galway, University Road, Galway (Ireland)
10. Physics Department, California Polytechnic State University, San Luis Obispo, CA 94307 (United States)
11. Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States)
12. Department of Physics, Purdue University, West Lafayette, IN 47907 (United States)
13. Department of Physics, Grinnell College, Grinnell, IA 50112-1690 (United States)
14. Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)

Indirect dark matter searches with ground-based gamma-ray observatories provide an alternative for identifying the particle nature of dark matter that is complementary to that of direct search or accelerator production experiments. We present the results of observations of the dwarf spheroidal galaxies Draco, Ursa Minor, Booetes 1, and Willman 1 conducted by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). These galaxies are nearby dark matter dominated objects located at a typical distance of several tens of kiloparsecs for which there are good measurements of the dark matter density profile from stellar velocity measurements. Since the conventional astrophysical background of very high energy gamma rays from these objects appears to be negligible, they are good targets to search for the secondary gamma-ray photons produced by interacting or decaying dark matter particles. No significant gamma-ray flux above 200 GeV was detected from these four dwarf galaxies for a typical exposure of {approx}20 hr. The 95% confidence upper limits on the integral gamma-ray flux are in the range (0.4-2.2) x 10{sup -12}photonscm{sup -2} s{sup -1}. We interpret this limiting flux in the context of pair annihilation of weakly interacting massive particles (WIMPs) and derive constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the WIMPs (({sigma}v) {approx}< 10{sup -23} cm{sup 3} s{sup -1} for m {sub {chi} {approx}}> 300 GeV c {sup -2}). This limit is obtained under conservative assumptions regarding the dark matter distribution in dwarf galaxies and is approximately 3 orders of magnitude above the generic theoretical prediction for WIMPs in the minimal supersymmetric standard model framework. However, significant uncertainty exists in the dark matter distribution as well as the neutralino cross sections which under favorable assumptions could further lower this limit.

• OSTI ID: 21460062
• Journal Information: Astrophysical Journal, Vol. 720, Issue 2; Other Information: DOI: 10.1088/0004-637X/720/2/1174; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ANNIHILATION
ASTROPHYSICS
CROSS SECTIONS
GALAXIES
GAMMA RADIATION
GEV RANGE 100-1000
NONLUMINOUS MATTER
PHOTON EMISSION
PHOTONS
STANDARD MODEL
SUPERSYMMETRY
TELESCOPES
BOSONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EMISSION
ENERGY RANGE
FIELD THEORIES
GEV RANGE
GRAND UNIFIED THEORY
INTERACTIONS
IONIZING RADIATIONS
MASSLESS PARTICLES
MATHEMATICAL MODELS
MATTER
PARTICLE INTERACTIONS
PARTICLE MODELS
PHYSICS
QUANTUM FIELD THEORY
RADIATIONS
SYMMETRY
UNIFIED GAUGE MODELS