中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Global constraints on diffusive particle acceleration by strong non-relativistic shocks

文献类型:期刊论文

作者Zhang, Yiran1,2; Liu, Siming1,2
刊名MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
出版日期2019-02-01
卷号482期号:4页码:5268-5274
关键词acceleration of particles shock waves cosmic rays ISM: supernova remnants
ISSN号0035-8711
DOI10.1093/mnras/sty3136
通讯作者Zhang, Yiran(zhangyr@pmo.ac.cn) ; Liu, Siming(liusm@pmo.ac.cn)
英文摘要Estimating the cosmic-ray acceleration efficiency epsilon in supernova remnants (SNRs) through observations is a challenging task in general. Based on the Rankine-Hugoniot shock conditions, we find an anticorrelation between epsilon and the power-law spectral index alpha of relativistic particle distribution produced via diffusive particle acceleration by non-relativistic shocks, implying more efficient acceleration in older SNRs with harder radio spectra. Then epsilon may be estimated from some hard radio spectral index measurements. Assuming the particle distribution in downstream of strong shocks to be a non-relativistic Maxwellian plus a relativistic power law with a high-energy cut-off, we also find that the injection rate for relativistic particles eta needs to greater than or similar to 10(-6) for a prominent decrease of the adiabatic index in SNRs, which implies higher compression ratio and lower values of alpha. This threshold of eta increases with the shock speed u(1), which may explain the relatively harder radio spectra of older SNRs with lower u(1). We show that eta and/or the relativistic cut-off momentum p(m) need to be low for old SNRs, and expect a gradual increase of epsilon as SNR evolves with gradually decreasing eta and p(m).
WOS关键词SUPERNOVA-REMNANTS ; CYGNUS LOOP ; ELECTRONS ; SPECTRA ; RADIO ; EMISSION ; DISTANCE ; ESCAPE ; TYCHO
WOS研究方向Astronomy & Astrophysics
语种英语
WOS记录号WOS:000462327300074
出版者OXFORD UNIV PRESS
源URL[http://libir.pmo.ac.cn/handle/332002/24202]  
专题中国科学院紫金山天文台
通讯作者Zhang, Yiran; Liu, Siming
作者单位1.Chinese Acad Sci, Purple Mt Observ, Key Lab Dark Matter & Space Astron, Nanjing 210034, Jiangsu, Peoples R China
2.Univ Sci & Technol China, Sch Astron & Space Sci, Hefei 230026, Anhui, Peoples R China
推荐引用方式
GB/T 7714
Zhang, Yiran,Liu, Siming. Global constraints on diffusive particle acceleration by strong non-relativistic shocks[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2019,482(4):5268-5274.
APA Zhang, Yiran,&Liu, Siming.(2019).Global constraints on diffusive particle acceleration by strong non-relativistic shocks.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,482(4),5268-5274.
MLA Zhang, Yiran,et al."Global constraints on diffusive particle acceleration by strong non-relativistic shocks".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 482.4(2019):5268-5274.

入库方式: OAI收割

来源:紫金山天文台

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