Abstract
We report the current status of the observations of supernova remnants (SNRs) with the LargeArea Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope, focusing on middle-agedSNRs that appear to be interacting with molecular clouds. Observations with the Fermi LAT in anenergy range from 0.2 GeV to ∼100 GeV have unveiled the presence of luminous GeV gamma-ray emission in middle-aged SNRs, providing a new insight into the shock-acceleration theoryand the origin of galactic cosmic rays. The middle-aged SNRsdetected by the Fermi LAT aregenerally much brighter in GeV than in TeV in terms of energy fl ux, which emphasizes the im-portanceof the GeV observations. Spectral steepeningin the Fermi-LATbandis commonlyfoundfor the GeV-luminous SNRs. Remarkably, most (if not all) of the GeV-luminous SNRs are knownto be interacting with molecular clouds, and they are also the strong sources of synchrotron radioemission. We discuss possible scenarios to explain the enhanced GeV gamma-ray emission in thecloud-interacting SNRs. Particular emphasis is placed on ascenario in which shock-acceleratedcosmic-rays are adiabatically compressed and energized asresult of radiative cooling behind thecloud shock.25th Texas Symposium on Relativistic AstrophysicsDecember 6-10, 2010Heidelberg, Germany
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
