The shape of the cutoff in the synchrotron emission of SN 1006 observed with XMM-Newton

TL;DR

This study uses XMM-Newton observations to analyze the X-ray synchrotron emission of SN 1006, demonstrating that electron energy cutoff is primarily limited by synchrotron losses, with a specific cutoff shape in the electron spectrum.

Contribution

It provides the first detailed spectral analysis confirming the loss-limited model and characterizing the cutoff shape of the electron spectrum in SN 1006.

Findings

Loss-limited model best fits the spectra

Electron cutoff shape is exp[-(p/p_cut)^2]

Residual thermal emission confirms previous density estimates

Abstract

Synchrotron X-ray emission from the rims of young supernova remnants allows us to study the high-energy tail of the electrons accelerated at the shock front. The analysis of X-ray spectra can provide information on the physical mechanisms that limit the energy achieved by the electrons in the acceleration process. We aim at verifying whether the maximum electron energy in SN 1006 is limited by synchrotron losses and at obtaining information on the shape of the cutoff in the X-ray synchrotron emission. We analyzed the deep observations of the XMM-Newton SN 1006 Large Program. We performed spatially resolved spectral analysis of a set of small regions in the nonthermal limbs and studied the X-ray spectra by adopting models that assume different electron spectra. We found out that a loss-limited model provides the best fit to all the spectra and this indicates that the shape of the cutoff in the electron momentum (p) distribution has the form exp[-(p/p_cut)^2]. We also detected residual thermal emission from shocked ambient medium and confirmed the reliability of previous estimates of the post-shock density. Our results indicate that radiative losses play a fundamental role in shaping the electron spectrum in SN 1006.