X-ray emission of baryonic gas in the universe: Luminosity-temperature relationship and soft-band background
文献类型：期刊论文
| 作者 | Zhang, TJ; Liu, JR; Feng, LL; He, P; Fang, LZ; Zhang, TJ , Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China |
| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2006 |
| 卷号 | 642期号:2页码:625-635 |
| 关键词 | Ly-alpha Forest Essentially Nonoscillatory Schemes Large-scale Structure Intergalactic Medium Transmitted Flux Intracluster Medium Power Spectrum Cosmological Simulations Burgers Turbulence Galaxy Clusters |
| ISSN号 | 0004-637X |
| 英文摘要 | We study the X-ray emission of baryon fluid in the universe using the WIGEON cosmological hydrodynamic simulations. It has been revealed that cosmic baryon fluid in the nonlinear regime behaves like Burgers turbulence, i.e., the fluid field consists of shocks. Like turbulence in incompressible fluid, the Burgers turbulence plays an important role in converting the kinetic energy of the fluid to thermal energy and heats the gas. We show that the simulation sample of the Lambda CDMmodel without adding extra heating sources can fit well the observed distributions of X-ray luminosity versus temperature (L-X vs. T) of galaxy groups and is also consistent with the distributions of X-ray luminosity versus velocity dispersion (L-X vs. sigma). Because the baryonic gas is multiphase, the L-X-T and L-X-sigma distributions are significantly scattered. If we describe the relationships by power laws L-X alpha T-alpha LT and L-X alpha sigma(alpha LV), we find alpha(LT) > 2: 5 and alpha(LV) > 2:1. The X-ray background in the soft 0.5-2 keV band emitted by the baryonic gas in the temperature range 10(5) < T < 10(7) K has also been calculated. We show that of the total background, ( 1) no more than 2% comes from the region with temperature less than 10(6.5) K, and ( 2) no more than 7% is from the region of dark matter with mass density rho dm < 50 (rho) over bar (dm). The region of rho dm > 50 (rho) over bar (dm) is generally clustered and discretely distributed. Therefore, almost all of the soft X-ray background comes from clustered sources, and the contribution from truly diffuse gas is probably negligible. This point agrees with current X-ray observations. |
| 学科主题 | Physics |
| URL标识 | 查看原文 |
| WOS记录号 | WOS:000237554200002 |
| 公开日期 | 2012-08-02 |
| 源URL | [http://ir.itp.ac.cn/handle/311006/5987]  |
| 专题 | 理论物理研究所_理论物理所1978-2010年知识产出 |
| 通讯作者 | Zhang, TJ , Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhang, TJ,Liu, JR,Feng, LL,et al. X-ray emission of baryonic gas in the universe: Luminosity-temperature relationship and soft-band background[J]. ASTROPHYSICAL JOURNAL,2006,642(2):625-635. |
| APA | Zhang, TJ,Liu, JR,Feng, LL,He, P,Fang, LZ,&Zhang, TJ , Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China.(2006).X-ray emission of baryonic gas in the universe: Luminosity-temperature relationship and soft-band background.ASTROPHYSICAL JOURNAL,642(2),625-635. |
| MLA | Zhang, TJ,et al."X-ray emission of baryonic gas in the universe: Luminosity-temperature relationship and soft-band background".ASTROPHYSICAL JOURNAL 642.2(2006):625-635. |
入库方式： OAI收割
来源：理论物理研究所
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