Log-Poisson non-Gaussianity of Ly alpha transmitted flux fluctuations at high redshift
文献类型：期刊论文
| 作者 | Lu, Yi1; Zhu, Weishan2,3; Chu, Yaoquan1; Feng, Long-long3 ; Fang, Li-Zhi2
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| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
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| 出版日期 | 2010-10-11 |
| 卷号 | 408期号:1页码:452-463 |
| 关键词 | cosmology: theory large-scale structure of Universe |
| ISSN号 | 0035-8711 |
| 英文摘要 | We investigate the non-Gaussian features of the intergalactic medium (IGM) at redshift z similar to 5-6 using the Ly alpha transmitted flux of quasar absorption spectra and a cosmological hydrodynamic simulation of the concordance Lambda CDM universe. We show that the neutral hydrogen mass density field and Ly alpha transmitted flux fluctuations possess all the non-Gaussian features predicted by the log-Poisson hierarchy. This depends only on two dimensionless parameters beta and gamma, describing, respectively, the intermittence and singularity of the random fields. We find that the non-Gaussianity of the Ly alpha transmitted flux of quasars from z = 4.9 to z = 6.3 can be well reconstructed by the hydrodynamical simulation samples. Although the Gunn-Peterson optical depth and its variance undergoes a significant evolution in the redshift range of 5-6, the intermittency measured by beta is almost redshift-independent in this range. More interestingly, the intermittency of the quasar's absorption spectra on physical scales 0.1-1 h(-1) Mpc in redshift 5-6 is found to be about the same as that on physical scales 1-10 h(-1) Mpc at redshifts 2-4. Considering the Jeans length is less than 0.1 h(-1) Mpc at z similar to 5, and 1 h(-1) Mpc at z similar to 2, these results imply that the non-linear evolution in high and low redshifts will lead the cosmic baryon fluid to a state similar to fully developed turbulence. The log-Poisson high-order behaviour of the current high-redshift data of a quasar's spectrum can be explained by the uniform ultraviolet background in the redshift range considered. We have also studied the log-Poisson non-Gaussianity by considering an inhomogeneous background. With several simplified models of the inhomogeneous background, we have found that the effect of the inhomogeneous background on the log-Poisson non-Gaussianity is no larger than 1 sigma. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 学科主题 | Astronomy & Astrophysics |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | FULLY-DEVELOPED TURBULENCE ; QUASI-STELLAR OBJECTS ; POWER SPECTRUM ; INTERGALACTIC MEDIUM ; APPROACHING REIONIZATION ; Z-SIMILAR-TO-6 QUASARS ; ABSORPTION-SPECTRUM ; FOREST ; EVOLUTION ; STATISTICS |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000283118100035 |
| 公开日期 | 2011-11-23 |
| 源URL | [http://159.226.72.40/handle/332002/1191]  |
| 专题 | 紫金山天文台_南极天文中心 |
| 作者单位 | 1.Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Anhui, Peoples R China 2.Univ Arizona, Dept Phys, Tucson, AZ 85721 USA 3.Purple Mt Observ, Nanjing 210008, Peoples R China |
| 推荐引用方式 GB/T 7714 | Lu, Yi,Zhu, Weishan,Chu, Yaoquan,et al. Log-Poisson non-Gaussianity of Ly alpha transmitted flux fluctuations at high redshift[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2010,408(1):452-463. |
| APA | Lu, Yi,Zhu, Weishan,Chu, Yaoquan,Feng, Long-long,&Fang, Li-Zhi.(2010).Log-Poisson non-Gaussianity of Ly alpha transmitted flux fluctuations at high redshift.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,408(1),452-463. |
| MLA | Lu, Yi,et al."Log-Poisson non-Gaussianity of Ly alpha transmitted flux fluctuations at high redshift".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 408.1(2010):452-463. |
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来源：紫金山天文台
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