Rauch, MichaelMurdin, P
Lya forest,翻译一下就是莱曼a森林。Lya发射线是由H原子的电子从n=2能级跃迁到n=1能级时发出的,波长是121.6nm。(吸收线就是反过来嘛)。quasar的光谱中常常充满这样的发射线。当然,也会存在n=1跃迁到更高的能级甚至直接电离的可能。 两张QSO的光谱 n=3到n=1的跃迁光子波长为102.6nm,也叫Lyβ线;13.6eV的电...
W. Purcell, "Lyman-alpha forest constraints on decaying dark matter," Phys. Rev. D88 no. 12, (2013) 123515, arXiv:1309.7354 [astro-ph.CO].M.-Y. Wang, R. A. C. Croft, A. H. G. Peter, A. R. Zentner and C. W. Purcell, Lyman-α forest constraints on decaying dark matter,...
Lyman-alpha-forest 例句 释义: 全部 更多例句筛选 1. But structure does, and the Lyman-alpha forest is very sensitive to it! 但结构需要,而且莱曼α森林对此极为敏感。 www.astronomy.com.cn© 2024 Microsoft 隐私声明和 Cookie 法律声明 广告 帮助 反馈...
Particle-Mesh Simulations of the Lyman-Alpha Forest Avery Meiksin 1 , Martin White 2 1 Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK 2 Astronomy Department, Harvard University 60 Garden Street, Cambridge, MA 02138 , USA 1 February 2008 ABSTRACT Numerica...
Consistent with previous estimates, we find that a moderate fraction of the Ly-$\\alpha$\\ forest clouds have been enriched with heavy elements at a level significantly below solar abundance. However, unlike the fairly uniform distribution of Ly-$\\alpha$\\ forest lines, we show that the C...
We have analyzed the clustering properties of Ly α forest lines in a HI column-density-limited sample over the redshift range z = 2.7–3.7. The sample has a relatively large lower cutoff column density ( N c = 10 14 cm 2 ), and is based on published high-resolution spectra of three...
produced by these forest lines.The He ii counterparts of the Lyα forest lines are highly saturated, and hence theircontributions to the observed opacity is limited. Assuming a He + /H 0 population ratioof 100 and that the power-law distribution dn/dN ∝ N −1.5 can be extended to a ...
Evolution of the Lyα Forest 3 “concordance model” (Ω m ≈ 1/3; Bahcall et al. 1999), but the latest CMB measurements combined with the H 0 Key Project value (Mould et al. 2000) suggest a higher Ω m as well (Pryke et al. 2001). Thus the Lyα forest provides ...
We have obtained a simple analytical approximation to the relationship between a rest-frame equivalent-width distribution for Ly-alpha forest absorption lines, N(W), and an H I column density distribution of the observed cloud number, N(N). Assuming a simple power-law form for N(N) proportio...