The interstellar medium in young supernova remnants: key to the production of cosmic X-rays and $\gamma$-rays

Abstract

We review recent progress in elucidating the relationship between high-energy radiation and the interstellar medium (ISM) in young supernova remnants (SNRs) with ages of $\sim$2000 yr, focusing in particular on RX J1713.7$-$3946 and RCW 86. Both SNRs emit strong nonthermal X-rays and TeV $\gamma$-rays, and they contain clumpy distributions of interstellar gas that includes both atomic and molecular hydrogen. We find that shock-cloud interactions provide a viable explanation for the spatial correlation between the X-rays and ISM. In these interactions, the supernova shocks hit the typically pc-scale dense cores, generating a highly turbulent velocity field that amplifies the magnetic field up to 0.1-1 mG. This amplification leads to enhanced nonthermal synchrotron emission around the clumps, whereas the cosmic-ray electrons do not penetrate the clumps. Accordingly, the nonthermal X-rays exhibit a spatial distribution similar to that of the ISM on the pc scale, while they are anticorrelated at sub-pc scales. These results predict that hadronic $\gamma$-rays can be emitted from the dense cores, resulting in a spatial correspondence between the $\gamma$-rays and the ISM. The current pc-scale resolution of $\gamma$-ray observations is too low to resolve this correspondence. Future $\gamma$-ray observations with the Cherenkov Telescope Array will be able to resolve the sub-pc-scale $\gamma$-ray distribution and provide clues to the origin of these cosmic $\gamma$-rays.

18 pages, 15 figures, accepted for publication in Astrophysics and Space Science

References in corpus (19)

• An eclipsing binary distance to the Large Magellanic Cloud accurate to 2 per cent
• Primary particle acceleration above 100 TeV in the shell-type Supernova Remnant RX J1713.7-3946 with deep H.E.S.S. observations
• Observations of the young supernova remnant RX J1713.7-3946 with the Fermi Large Area Telescope
• Inverse Compton Emission from Galactic Supernova Remnants: Effect of the Interstellar Radiation Field
• Study of Nonthermal Emission from SNR RX J1713.7-3946 with Suzaku
• Theory of cosmic ray production in the supernova remnant RX J1713.7-3946
• Gamma ray emission from SNR RX J1713.7-3946 and the origin of galactic cosmic rays
• Characterizing the non-thermal emission of Cas A
• Hadronic gamma-rays from RX J1713.7-3946?
• Optically thick HI dominant in the local interstellar medium; an alternative interpretation to "dark gas"
• Updated radio $\Sigma -D$ relation for Galactic supernova remnants
• Expansion measurement of Supernova Remnant RX J1713.7-3946
• Bell-Instability-Mediated Spectral Modulation of Hadronic Gamma Rays from a Supernova Remnant Interacting with a Molecular Cloud
• ALMA CO Observations of the Gamma-Ray Supernova Remnant RX J1713.7-3946: Discovery of Shocked Molecular Cloudlets and Filaments at 0.01 pc scales
• Shock-Cloud Interaction in the Southwestern Rim of RX J1713.7$-$3946 Evidenced by Chandra X-ray Observations
• Discovery of a Pulsar-powered Bow Shock Nebula in the Small Magellanic Cloud Supernova Remnant DEMS5
• Gas and Dust Properties in the Chamaeleon Molecular Cloud Complex based on the Optically Thick HI
• X-ray Hotspots in the Northwest Shell of the Supernova Remnant RX J1713.7$-$3946
• Study of the Cosmic Rays and Interstellar Medium in Local HI Clouds using Fermi-LAT Gamma-Ray Observations

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• Physical properties of the molecular cloud, N4, in SS433; Evidence for an interaction of molecular cloud with the jet from SS433
• A First-look at Spatially-resolved Infrared Supernova Remnants in M33 with JWST
• A Study of Radio Knots within Supernova Remnant Cassiopeia A
• Measurement of the Forward Shock Velocities of the Supernova Remnant N132D Based on the Thermal X-ray Emission
• Survival of Molecular Complexity under Recent Supernova Feedback: Detection of Hot Cores in RX J1713.7-3946