Time-Dependent Escape of Cosmic Rays from Supernova Remnants, and their Interaction with Dense Media

Abstract

Context. Supernova remnants (SNRs) are thought to be the main source of Galactic cosmic rays (CRs) up to the "knee" in CR spectrum. During the evolution of a SNR, the bulk of the CRs are confined inside the SNR shell. The highest-energy particles leave the system continuously, while the remaining adiabatically cooled particles are released when the SNR has expanded sufficiently and decelerated so that the magnetic field at the shock is no longer able to confine them. Particles escaping from the parent system may interact with nearby molecular clouds, producing $\gamma$-rays in the process via pion decay. The soft gamma-ray spectra observed for a number of SNRs interacting with molecular clouds, however, challenge current theories of non-linear particle acceleration that predict harder spectra. Aims. We study how the spectrum of escaped particles depends on the time-dependent acceleration history in both Type Ia and core-collapse SNRs, as well as on different assumptions about the diffusion coefficient in the vicinity of the SNR. Methods. We solve the CR transport equation in a test-particle approach combined with numerical simulations of SNR evolution. Results. We extend our method for calculating the cosmic-ray acceleration in SNRs to trace the escaped particles in a large volume around SNRs. We calculate the evolution of the spectra of CRs that have escaped from a SNR into a molecular cloud or dense shell for two diffusion models. We find a strong confinement of CRs in a close region around the SNR, and a strong dilution effect for CRs that were able to propagate out as far as a few SNR radii.

arXiv comment11 pages, 8 figures. Accepted for publication in A&A

References in corpus (39)

• Constraints on cosmic-ray propagation models from a global Bayesian analysis
• Broad-band nonthermal emission from molecular clouds illuminated by cosmic rays from nearby supernova remnants
• Observations of the young supernova remnant RX J1713.7-3946 with the Fermi Large Area Telescope
• Observation of Supernova Remnant IC443 with the Fermi Large Area Telescope
• On the spectrum of high-energy cosmic rays produced by supernova remnants in the presence of strong cosmic-ray streaming instability and wave dissipation
• 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
• On the role of injection in kinetic approaches to nonlinear particle acceleration at non-relativistic shock waves
• Fermi LAT Observations of the Supernova Remnant W28 (G6.4-0.1)
• HESS Observations and VLT Spectroscopy of PG 1553+113
• Nonthermal Radiation of Young Supernova Remnants
• Spectrum of Galactic Cosmic Rays Accelerated in Supernova Remnants
• Discovery of TeV Gamma Ray Emission from Tycho's Supernova Remnant
• Fermi-LAT discovery of GeV gamma-ray emission from the young supernova remnant Cassiopeia A
• First detection of VHE gamma-rays from SN 1006 by H.E.S.S
• Gamma rays from molecular clouds illuminated by cosmic rays escaping from interacting supernova remnants
• The Evolution of Supernovae in Circumstellar Wind-Blown Bubbles I. Introduction and One-Dimensional Calculations
• Diffusive Shock Acceleration with Magnetic Amplification by Non-resonant Streaming Instability in SNRs
• Observation of Extended VHE Emission from the Supernova Remnant IC 443 with VERITAS
• Fermi-LAT Detection of the Young SuperNova Remnant Tycho
• The Evolution of Supernovae in Circumstellar Wind Bubbles II: Case of a Wolf-Rayet star
• The contribution of supernova remnants to the galactic cosmic ray spectrum
• Fermi LAT Observations of Supernova Remnants Interacting with Molecular Clouds
• Escaping the accelerator; how, when and in what numbers do cosmic rays get out of supernova remnants?
• Discovery of gamma-ray emission from the shell-type supernova remnant RCW 86 with H.E.S.S
• On the escape of particles from cosmic ray modified shocks
• Gamma rays from molecular clouds illuminated by accumulated diffusive protons from supernova remnant W28
• Molecular Clouds as a Probe of Cosmic-Ray Acceleration in a Supernova Remnant
• Observations of the shell-type SNR Cassiopeia A at TeV energies with VERITAS
• Core-collapse model of broadband emission from SNR RX J1713.7-3946 with thermal X-rays and Gamma-rays from escaping cosmic rays
• The Interaction of Cosmic Rays with Diffuse Clouds
• Gamma-ray emission of accelerated particles escaping a supernova remnant in a molecular cloud
• Particle Spectra from Acceleration at Forward and Reverse Shocks of Young Type Ia Supernova Remnants
• Steady-State Solutions in Nonlinear Diffusive Shock Acceleration
• Cosmic Ray streaming from SNRs and gamma ray emission from nearby molecular clouds
• Gamma-Rays Produced in Cosmic-Ray Interactions and the TeV-band Spectrum of RX J1713-3946
• Propagation and Source Energy Spectra of Cosmic-Ray Nuclei at High Energies
• Slow Diffusion of Cosmic-Rays around a Supernova Remnant
• Alfven Wave Amplification and Self-Containment of Cosmic-Rays Escaping from a Supernova Remnant
• Synchrotron aging and the radio spectrum of SN 1993J

Cited by in corpus (26)

• Cosmic ray production in supernovae
• The origin of the spectral intensities of cosmic-ray positrons
• X-ray Measurements of the Particle Acceleration Properties at Inward Shocks in Cassiopeia A
• Cosmic-ray acceleration and escape from post-adiabatic Supernova remnants
• Acceleration of cosmic rays by young core-collapse supernova remnants
• Transport of magnetic turbulence in Supernova remnants
• Wind nebulae and supernova remnants of very massive stars
• Non-thermal emission from stellar bow shocks
• Analysis of GeV-band gamma-ray emission from SNR RX J1713.7-3946
• Spectral softening in core-collapse supernova remnant expanding inside wind-blown bubble
• Non-thermal emission from the reverse shock of the youngest galactic Supernova remnant G1.9+0.3
• Exploring the Gamma-Ray Emissivity of Young Supernova Remnants I: Hadronic Emission
• Non-linear diffusion of cosmic rays escaping from supernova remnants: Cold partially neutral atomic and molecular phases
• Discovery of X-ray Emission from the Galactic Supernova Remnant G32.8-0.1 with Suzaku
• X-ray Spectroscopy of the Mixed Morphology Supernova Remnant W28 with XMM-Newton
• Leptonic non-thermal emission from supernova remnants evolving in the circumstellar magnetic field
• Post-adiabatic supernova remnants in an interstellar magnetic field: oblique shocks and non-uniform environment
• X-Ray Luminous Supernovae: Threats to Terrestrial Biospheres
• Mixing of materials in magnetised core-collapse supernova remnants
• A Self-Consistent Explanation of TeV Emissions from HESS J1640-465 and HESS J1641-463
• A Hydro-Based MCMC Analysis of SNR 0509-67.5 Revealing the Explosion Properties from Fluid Discontinuities Alone
• A Possible Hadronic Origin of TeV Photon Emission from SNR G106.3+2.7
• Supernova remnants in super bubbles as cosmic ray accelerators
• On the Evolution of the Maximum Energy of Accelerated Particles in Young Supernova Remnants
• Interaction of escaping cosmic rays with molecular clouds
• Spectrally resolved cosmic rays: II -- Momentum-dependent cosmic ray diffusion drives powerful galactic winds