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 |
| DOI | 10.1093/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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