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arXiv · 1007.3138

Cosmic-Ray Acceleration Efficiency vs Temperature Equilibration: the Case of SNR 0509-67.5

E. A. Helder·D. Kosenko·J. Vink
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Abstract

We study the 0509-67.5 supernova remnant in the Large Magellanic Cloud with the VLT/FORS2 spectrograph. We detect a broad component in the H-alpha emission with a FWHM of 2680 \pm 70 km/s and 3900 \pm 800 km/s for the southwest (SW) and northeast (NE) shocks respectively. For the SW, the proton temperature appears to be too low for the shock velocity, which we attribute to a cosmic-ray pressure behind the shock front of at least 20% of the total pressure. For the NE, the post-shock proton temperature and the shock velocity are compatible, only if the plasma behind the shock front has a degree of thermal equilibrium of over 20%, which is at odds with current models for temperature equilibration behind fast shocks, which do not accelerate cosmic rays. If we assume the electron temperature to be less than 10% of the proton temperature, we find a post-shock cosmic-ray pressure of at least 7%.

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E. A. Helder, D. Kosenko, J. Vink. 2010-07-19. Cosmic-Ray Acceleration Efficiency vs Temperature Equilibration: the Case of SNR 0509-67.5. https://doi.org/10.1088/2041-8205%2F719%2F2%2Fl140

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