TeV cosmic ray nuclei acceleration in shell-type supernova remnants with hard $\gamma$-ray spectra

Abstract

The emission mechanism for hard $\gamma$-ray spectra from supernova remnants (SNRs) is still a matter of debate. Recent multi-wavelength observations of TeV source HESS J1912+101 show that it is associated with an SNR with an age of $\sim 100$ kyrs, making it unlikely produce the TeV $\gamma$-ray emission via leptonic processes. We analyzed Fermi observations of it and found an extended source with a hard spectrum. HESS J1912+101 may represent a peculiar stage of SNR evolution that dominates the acceleration of TeV cosmic rays. By fitting the multi-wavelength spectra of 13 SNRs with hard GeV $\gamma$-ray spectra with simple emission models with a density ratio of GeV electrons to protons of $\sim 10^{-2}$, we obtain reasonable mean densities and magnetic fields with a total energy of $\sim 10^{50}$ ergs for relativistic ions in each SNR. Among these sources, only two of them, namely SN 1006 and RCW 86, favor a leptonic origin for the $\gamma$-ray emission. The magnetic field energy is found to be comparable to that of the accelerated relativistic ions and their ratio has a tendency of increase with the age of SNRs. These results suggest that TeV cosmic rays mainly originate from SNRs with hard $\gamma$-ray spectra.

25 pages, 21 figures, 2 tables, Accepted for Publication in ApJ

References in corpus (30)

• HI4PI: A full-sky HI survey based on EBHIS and GASS
• Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
• Measurement of the cosmic-ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite
• H.E.S.S. observations of the supernova remnant RX J0852.0-4622: shell-type morphology and spectrum of a widely extended VHE gamma-ray source
• First detection of VHE gamma-rays from SN 1006 by H.E.S.S
• 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
• Hadronic gamma-rays from RX J1713.7-3946?
• Discovery of the radio and X-ray counterpart of TeV Gamma-ray source HESS J1731-347
• The Slow X-Ray Expansion of the Northwestern Rim of the Supernova Remnant RX J0852.0-4622
• The First X-Ray Proper-Motion Measurements of the Forward Shock in the Northeastern Limb of SN 1006
• Unified model for the gamma-ray emission of supernova remnants
• Interstellar protons in the TeV gamma-ray SNR HESS J1731-347:Possible evidence for the coexistence of hadronic and leptonic gamma-rays
• A detailed study of the interstellar protons toward the TeV $\gamma$-ray SNR RX J0852.0$-$4622 (G266.2$-$1.2, Vela Jr.); a third case of the $\gamma$-rays and ISM spatial correspondence
• Detection of two TeV shell-type remnants at GeV energies with Fermi-LAT: HESS J1731-347 and SN 1006
• Expansion measurement of Supernova Remnant RX J1713.7-3946
• The Search for Faint Radio Supernova Remnants in the Outer Galaxy: Five New Discoveries
• Search for Pulsar Wind Nebula Associations of Unidentified TeV Gamma-Ray Sources
• Anomalous distributions of primary cosmic rays as evidence for time-dependent particle acceleration in Supernova remnants
• X-ray Hotspot Flares and Implications for Cosmic Ray Acceleration and Magnetic Field amplification in Supernova Remnants
• Bell-Instability-Mediated Spectral Modulation of Hadronic Gamma Rays from a Supernova Remnant Interacting with a Molecular Cloud
• Gamma-Ray Emission from Supernova Remnant Interaction with Molecular Clumps
• Is HESS J1912+101 associated with an old Supernova Remnant?
• Detection of GeV $\gamma$-ray emission in the direction of HESS J1731-347 with Fermi-LAT
• Detection of GeV Gamma-rays from HESS J1534-571 and Multiwavelength Implications for the Origin of the Non-thermal Emission
• XMM-Newton observations of the non-thermal supernova remnant HESS J1731-347 (G353.6-0.7)
• Is Supernova Remnant Cassiopeia A a PeVatron?
• G279.0+1.1: a new extended source of high-energy gamma rays
• Global Constraints on Diffusive Particle Acceleration by Strong Nonrelativistic Shocks
• Modeling the non-thermal emission of the gamma Cygni Supernova Remnant up to the highest energies