Publication Date:
2009-06-27
Description:
Cosmic rays are the most energetic particles arriving at Earth. Although most of them are thought to be accelerated by supernova remnants, the details of the acceleration process and its efficiency are not well determined. Here we show that the pressure induced by cosmic rays exceeds the thermal pressure behind the northeast shock of the supernova remnant RCW 86, where the x-ray emission is dominated by synchrotron radiation from ultrarelativistic electrons. We determined the cosmic-ray content from the thermal Doppler broadening measured with optical spectroscopy, combined with a proper-motion study in x-rays. The measured postshock proton temperature, in combination with the shock velocity, does not agree with standard shock heating, implying that 〉50% of the postshock pressure is produced by cosmic rays.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Helder, E A -- Vink, J -- Bassa, C G -- Bamba, A -- Bleeker, J A M -- Funk, S -- Ghavamian, P -- van der Heyden, K J -- Verbunt, F -- Yamazaki, R -- New York, N.Y. -- Science. 2009 Aug 7;325(5941):719-22. doi: 10.1126/science.1173383. Epub 2009 Jun 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astronomical Institute Utrecht, Utrecht University, Post Office Box 80000, NL-3508 TA Utrecht, Netherlands. e.a.helder@uu.nl〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19556465" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
