XMM-Newton evidence of shocked ISM in SN 1006: indications of hadronic acceleration

Abstract

Shock fronts in young supernova remnants are the best candidates for being sites of cosmic ray acceleration up to a few PeV, though conclusive experimental evidence is still lacking. Hadron acceleration is expected to increase the shock compression ratio, providing higher postshock densities, but X-ray emission from shocked ambient medium has not firmly been detected yet in remnants where particle acceleration is at work. We exploited the deep observations of the XMM-Newton Large Program on SN 1006 to verify this prediction. We performed spatially resolved spectral analysis of a set of regions covering the southeastern rim of SN 1006. We studied the spatial distribution of the thermodynamic properties of the ambient medium and carefully verified the robustness of the result with respect to the analysis method. We detected the contribution of the shocked ambient medium. We also found that the postshock density of the interstellar medium significantly increases in regions where particle acceleration is efficient. Under the assumption of uniform preshock density, we found that the shock compression ratio reaches a value of ~6 in regions near the nonthermal limbs. Our results support the predictions of shock modification theory and indicate that effects of acceleration of cosmic ray hadrons on the postshock plasma can be observed in supernova remnants.

Accepted for publication in A&A

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Cited by in corpus (22)

• A High-Resolution X-Ray and Optical Study of SN 1006: Asymmetric Expansion and Small-Scale Structure in a Type Ia Supernova Remnant
• Kinetic Simulations of Cosmic-Ray-Modified Shocks II: Particle Spectra
• Kinetic Simulations of Cosmic-Ray-Modified Shocks I: Hydrodynamics
• Study of TeV shell supernova remnants at gamma-ray energies
• Electron-Ion Temperature Ratio in Astrophysical Shocks
• The northwestern ejecta knot in SN 1006
• Shock-cloud interaction and particle acceleration in SN 1006
• Detection of two TeV shell-type remnants at GeV energies with Fermi-LAT: HESS J1731-347 and SN 1006
• The supernova remnant SN 1006 as a Galactic particle accelerator
• Evolution and observational signatures of the cosmic ray electron spectrum in SN 1006
• XMM-Newton Large Program on SN1006 - I: Methods and Initial Results of Spatially-Resolved Spectroscopy
• The shape of the cutoff in the synchrotron emission of SN 1006 observed with XMM-Newton
• Electron Heating, Magnetic Field Amplification, and Cosmic Ray Precursor Length at Supernova Remnant Shocks
• Measurement of the X-ray proper motion in the south-east rim of RX J1713.7-3946
• An Expanding Shell of Neutral Hydrogen Associated with SN 1006: Hints for the Single-Degenerate Origin and Faint Hadronic Gamma-Rays
• Modeling the shock-cloud interaction in SN 1006: unveiling the origin of nonthermal X-ray and gamma-ray emission
• Parametric studies of cosmic ray acceleration in supernova remnants
• XMM-Newton Large Program on SN1006 - II: Thermal Emission
• Plasma heating and particle acceleration in collisionless shocks through astrophysical observations
• X-ray emitting structures in the Vela SNR: ejecta anisotropies and progenitor stellar wind residuals
• Hadronic particle acceleration in the supernova remnant SN 1006 as traced by Fermi-LAT observations
• The loss-limited electron energy in SN 1006: effects of the shock velocity and of the diffusion process