论文标题
在暗物质光环中填充HI气体：I。方法
Populating HI gas in dark matter halos: I. method
论文作者
论文摘要
我们结合了斯隆数字天空调查（SDSS）和Arecibo Legacy Fast Alfa调查（alfalfa）的数据，以在暗物质Halos中建立HI GAS含量的经验模型。我们的SDSS DR7 Galaxy组样品与苜蓿HI来源之间的交叉匹配提供了16,520个HI-GALAXY对的目录，其中14,270个星系组（Halos）。使用这些匹配的对，我们使用两个组件在HALOS中对HI气体质量分布进行建模：1）{\ it int intu} Galaxy关系，涉及HI Masses，colors $ $（{\ rm g-r}）$和恒星质量2）{\ it iT ext iT extip it ext iT extip iT ext iT ext iT exu} extu} exi exu}对卤素质量/环境的依赖性。我们发现，如果我们仅使用星系相关的缩放关系来预测HI气体分布（仅是组件1），则与苜蓿观测值相比，HI检测的数量被显着高估了。我们介绍了一个概念，用于将HI质量/成员在标记为“效率”因子的不同质量的晕圈中生存，以描述Halo在保留其HI检测方面的可能性。考虑到上述考虑，我们构建了一个“基于光晕的HI质量模型”，该模型不仅可以预测星系的HI质量，而且还产生了相似的数量，即恒星，光晕质量和卫星分数分布与从观察数据中获取的HI检测。
We combine data from the Sloan Digital Sky Survey (SDSS) and the Arecibo Legacy Fast ALFA Survey (ALFALFA) to establish an empirical model for the HI gas content within dark matter halos. A cross-match between our SDSS DR7 galaxy group sample and the ALFALFA HI sources provides a catalog of 16,520 HI-galaxy pairs within 14,270 galaxy groups (halos). Using these matched pairs, we model the HI gas mass distributions within halos using two components: 1) {\it in situ} galaxy relations that involve the HI masses, colors $({\rm g-r})$ and stellar masses 2) an {\it ex situ} dependence of the HI mass on the halo mass/environment. We find that if we solely use galaxy associated scaling relations to predict the HI gas distribution (solely component 1), the number of HI detections is significantly over-predicted with respect the ALFALFA observations. We introduce a concept for the survival of the HI masses/members within halos of different masses labelled as the `efficiency' factor, in order to describe the probability that a halo has in retaining its HI detections. Taking the above consideration into account we construct a `halo based HI mass model' which does not only predict the HI masses of galaxies, but also yields similar number, stellar, halo mass and satellite fraction distributions to the HI detections retrieved from observational data.
