GAMMA-RAY EMISSION FROM SUPERNOVA REMNANT INTERACTIONS WITH MOLECULAR CLUMPS

Journal Article · Tue Apr 01 04:00:00 EDT 2014 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/784/2/L35· OSTI ID:22365930

Tang, Xiaping

Observations of the middle-aged supernova remnants IC 443, W28, and W51C indicate that the brightnesses at GeV and TeV energies are correlated with each other and with regions of molecular clump interaction, but not with the radio synchrotron brightness. We suggest that the radio emission is primarily associated with a radiative shell in the interclump medium of a molecular cloud, while the γ-ray emission is primarily associated with the interaction of the radiative shell with molecular clumps. The shell interaction produces a high pressure region, so that the γ-ray luminosity can be approximately reproduced even if shock acceleration of particles is not efficient, provided that energetic particles are trapped in the cooling region. In this model, the spectral shape ≳ 2 GeV is determined by the spectrum of cosmic ray protons. Models in which diffusive shock acceleration determines the spectrum tend to underproduce TeV emission because of the limiting particle energy that is attained.

• OSTI ID: 22365930
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 784; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
APPROXIMATIONS
BRIGHTNESS
COSMIC RADIATION
GAMMA RADIATION
GEV RANGE
LUMINOSITY
PHOTON EMISSION
SUPERNOVA REMNANTS
TEV RANGE
TRAPPING