标题： 限制星系际介质的温度密度关系与莱曼$α$和$β$森林 显示英文标题

标题： Constraining the temperature-density relation of the intergalactic medium with the Lyman-$α$ and $β$ forests

摘要： 再电离后星系间介质的热状态由温度和密度之间的幂律关系表征，其斜率由参数$\gamma$确定。 我们描述了一种利用 Lyman-$\alpha$和$\beta$森林中的流量曲率比来测量$\gamma$的新方法。 在给定红移下，这种曲率比包含了 Lyman-$\alpha$和$\beta$吸收所追踪的不同气体密度的信息。 计算相对简单且快速，并且似乎能够抵抗几种观测不确定性。 我们将此技术应用于来自甚大望远镜的 27 条高分辨率类星体光谱样本。 虽然在这些光谱上有望实现$\gamma$的预期统计误差，但要充分发挥其潜力，曲率比对前景 Lyman-$\alpha$森林中气体热状态的依赖关系需要进一步详细的正向建模。 显示英文摘要

摘要： The post-reionization thermal state of the intergalactic medium is characterized by a power-law relationship between temperature and density, with a slope determined by the parameter $\gamma$. We describe a new method to measure $\gamma$ using the ratio of flux curvature in the Lyman-$\alpha$ and $\beta$ forests. At a given redshift, this curvature ratio incorporates information from the different gas densities traced by Lyman-$\alpha$ and $\beta$ absorption. It is relatively simple and fast to compute and appears robust against several observational uncertainties. We apply this technique to a sample of 27 high-resolution quasar spectra from the Very Large Telescope. While promising statistical errors on $\gamma$ appear to be achievable with these spectra, to reach its full potential, the dependence of the curvature ratio on the thermal state of the gas in the foreground Lyman-$\alpha$ forest will require further, detailed forward modelling.