当然,电子跃迁到高能级的概率是更小的。在quasar的光谱中,波长短于91.2nm×(1+zQSO)的部分,对应完全电离的H气体云,光谱会被大大压低,这称为Lyman limit absorption。 在quasars中,Lya线常常是比较宽的。因为H原子气体在其中心附近运动很快,有很大的速度弥散,因此多普勒展宽也比较严重。 从quasar的光谱中可以看到,...
Rauch, MichaelMurdin, P
W. Purcell, Lyman-alpha Forest Constraints on Decaying Dark Matter, arXiv:1309.7354 [astro-ph.CO].Wang, M-Y, Croft, RAC, Peter, AHG, Zentner, AR, Purcell, CW (2013) Lyman-α forest constraints on decaying dark matter. Phys. Rev. D 88: pp. 123515...
Keck telescope to obtain a high resolution, very high signal-to-noise spectrum of this z = 3.63 quasar; the spectrum covers wavelengths from below Lyman β up to the C IV emission line. Consistent with previous estimates, we find that a moderate fraction of the Ly α forest clouds have ...
For the purpose of studying the properties of heavy-elements associated with the Lyman-$\\alpha$\\ forest, we observed the gravitational lens Q1422+2309. We used the HIRES instrument on the W.M. Keck telescope to obtain a high-resolution, very high signal-to-noise spectrum of this z=...
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 ...
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 3 τ(u) = A dx ρ(x) ¯ ρ 2 T(x) −0.7 b −1 e −(u−u 0 ) 2 /b 2 (4) where u0 = xaHL box + v los and b = 2kBT/mH is the Doppler parameter, where mH is the mass of a hydrogen atom. The flux at...
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...
The Evolution of the Lyman Alpha Forest From z ∼ 3 →0 Romeel Dav´e Steward Observatory, Univ. of Arizona, 933 N. Cherry Ave., Tucson, AZ, USA Abstract. I review results obtained from studies of the high-redshift Lyα forest, ...