DIRECT EVIDENCE FOR HADRONIC COSMIC-RAY ACCELERATION IN THE SUPERNOVA REMNANT IC 443

Journal Article · Sat Feb 20 00:00:00 EST 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/710/2/L151; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301271

Tavani, M; Argan, A; Cocco, V; D'Ammando, F; Costa, E; De Paris, G; Monte, E Del; Donnarumma, I; Evangelista, Y; Feroci, M ^[1]; Giuliani, A; Chen, A W; Caraveo, P; Contessi, T ^[2]; Barbiellini, G ^[3]; Bulgarelli, A; Cocco, G Di; Fuschino, F ^[4]; Cattaneo, P W ^[5]; Ferrari, A ^[6]

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1. INAF/IASF-Roma, I-00133 Roma (Italy)
2. INAF/IASF-Milano, I-20133 Milano (Italy)
3. Dipartimento di Fisica and INFN Trieste, I-34127 Trieste (Italy)
4. INAF/IASF-Bologna, I-40129 Bologna (Italy)
5. INFN-Pavia, I-27100 Pavia (Italy)
6. CIFS-Torino, I-10133 Torino (Italy)

The supernova remnant (SNR) IC 443 is an intermediate-age remnant well known for its radio, optical, X-ray, and gamma-ray energy emissions. In this Letter, we study the gamma-ray emission above 100 MeV from IC 443 as obtained by the AGILE satellite. A distinct pattern of diffuse emission in the energy range 100 MeV-3 GeV is detected across the SNR with its prominent maximum (source 'A') localized in the northeastern shell with a flux F=(47{+-}10)x10{sup -8} photons cm{sup -2}s{sup -1} above 100 MeV. This location is the site of the strongest shock interaction between the SNR blast wave and the dense circumstellar medium. Source 'A' is not coincident with the TeV source located 0.4 deg. away and associated with a dense molecular cloud complex in the SNR central region. From our observations, and from the lack of detectable diffuse TeV emission from its northeastern rim, we demonstrate that electrons cannot be the main emitters of gamma rays in the range 0.1-10 GeV at the site of the strongest SNR shock. The intensity, spectral characteristics, and location of the most prominent gamma-ray emission together with the absence of cospatial detectable TeV emission are consistent only with a hadronic model of cosmic-ray acceleration in the SNR. A high-density molecular cloud (cloud 'E') provides a remarkable 'target' for nucleonic interactions of accelerated hadrons; our results show enhanced gamma-ray production near the molecular cloud/shocked shell interaction site. IC 443 provides the first unambiguous evidence of cosmic-ray acceleration by SNRs.

• OSTI ID: 21301271
• Journal Information: Astrophysical Journal Letters, Vol. 710, Issue 2; Other Information: DOI: 10.1088/2041-8205/710/2/L151; Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ACCELERATION
COSMIC RADIATION
ELECTRONS
GAMMA RADIATION
HADRONS
MEV RANGE 100-1000
PHOTONS
SATELLITES
SUPERNOVA REMNANTS
SUPERNOVAE
TEV RANGE