分类: 天文学 >> 天文学 提交时间: 2023-02-19
摘要: The absorption by neutral hydrogen in the intergalactic medium (IGM) produces
the Ly$\alpha$ forest in the spectra of quasars. The Ly$\alpha$ forest
absorbers have a broad distribution of neutral hydrogen column density $N_{\rm
HI}$ and Doppler $b$ parameter. The narrowest Ly$\alpha$ absorption lines (of
lowest $b$) with neutral hydrogen column density above $\sim 10^{13}{\rm
cm^{-2}}$ are dominated by thermal broadening, which can be used to constrain
the thermal state of the IGM. Here we constrain the temperature-density
relation $T=T_0(\rho/\bar{\rho})^{\gamma-1}$ of the IGM at $1.6
分类: 天文学 >> 天文学 提交时间: 2023-02-19
摘要: The absorption by neutral hydrogen in the intergalactic medium (IGM) produces
the Ly$\alpha$ forest in the spectra of quasars. The Ly$\alpha$ forest
absorbers have a broad distribution of neutral hydrogen column density $N_{\rm
HI}$ and Doppler $b$ parameter. The narrowest Ly$\alpha$ absorption lines (of
lowest $b$) with neutral hydrogen column density above $\sim 10^{13}{\rm
cm^{-2}}$ are dominated by thermal broadening, which can be used to constrain
the thermal state of the IGM. Here we constrain the temperature-density
relation $T=T_0(\rho/\bar{\rho})^{\gamma-1}$ of the IGM at $1.6