Fermi large area telescope detection of a break in the gamma-ray spectrum of the supernova remnant Cassiopeia A

Journal Article · Fri Dec 20 00:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/779/2/117· OSTI ID:22348453

Yuan, Yajie; Funk, Stefan; Lande, Joshua; Tibaldo, Luigi ^[1]; Jóhannesson, Gülauger ^[2]; Uchiyama, Yasunobu ^[3]

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1. W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)
2. Science Institute, University of Iceland, IS-107 Reykjavik (Iceland)
3. 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501 (Japan)

We report on observations of the supernova remnant Cassiopeia A in the energy range from 100 MeV to 100 GeV using 44 months of observations from the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope. We perform a detailed spectral analysis of this source and report on a low-energy break in the spectrum at 1.72{sub −0.89}{sup +1.35} GeV. By comparing the results with models for the gamma-ray emission, we find that hadronic emission is preferred for the GeV energy range.

• OSTI ID: 22348453
• Journal Information: Astrophysical Journal, Vol. 779, 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
ACCELERATION
COMPARATIVE EVALUATIONS
DETECTION
EMISSION
GAMMA RADIATION
GAMMA SPECTRA
GEV RANGE
MEV RANGE 100-1000
SPACE
SUPERNOVA REMNANTS
SUPERNOVAE
TELESCOPES