THE DIFFUSE GeV-TeV {gamma}-RAY EMISSION OF THE CYGNUS REGION

Journal Article · Mon Apr 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/695/2/883; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21296254

Xiaojun, Bi; Yue, Wang; Qiang, Yuan ^[1]

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1. Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

Recently the Milagro experiment observed diffuse multi-TeV gamma ray emission in the Cygnus region, which is significantly stronger than what is predicted by the Galactic cosmic ray model. However, the sub-GeV observation by EGRET shows no excess to the prediction based on the same model. This TeV excess implies possible high-energy cosmic rays populated in the region with harder spectrum than that observed on the Earth. In the work we studied this theoretical speculation in detail. We find that, a diffuse proton source with power index {alpha} {sub p} {approx}< 2.3, or a diffuse electron source with power index {alpha} {sub e} {approx}< 2.6 can reproduce the Milagro's observation without conflicting with the EGRET data. Further detections on neutrinos, a diagnostic of the hadronic model, and hard X-ray synchrontron radiation, a diagnostic of the lepton model, help to break this degeneracy. In combination with the gamma ray observations to several hundred GeV by Fermi, we will be able to understand the diffuse emission mechanisms in the Cygnus region better.

• OSTI ID: 21296254
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 695; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ACCELERATION
COSMIC RADIATION
ELECTRON SOURCES
GAMMA RADIATION
GEV RANGE
HADRONS
HARD X RADIATION
NEUTRINOS
PROTON SOURCES
TEV RANGE