论文标题
观察Lyman- $α$ Universe
Observations of the Lyman-$α$ Universe
论文作者
论文摘要
自1990年代后期首次发现高红移的宇宙以来，氢莱曼-yman-$ a $α$（ly $α$）排放一直是高红移宇宙的主要观察探针之一。由于强劲的$α$发射起源于最丰富元素的共振散射和重组，因此，$α$观测值不仅见证了星形形成和AGN的HII区域，而且还见证了圆周型培养基（CGM）中的弥漫性HI气体和弥漫性HI气体（CGM）和 - 层间培养基（IGM）。在这里，我们回顾了$α$来源，并介绍迄今为止的理论解释。我们得出的结论是：1）$ z \ gtrsim 2 $，带有$ l^*$ ly $ ly $α$ luminosity的典型$α$发射极（LAE）是当地矮星系的高$ z $ flos，是一个高$ z $，是一个紧凑的金属畅销金属畅销的星星（SFG），均为$ 10} $ 10} m_ \ odot $（$ 10^{10-11} m_ \ odot $）和$ 1-10 m_ \ odot $ yr $^{ - 1} $； 2）高$ z $ sfgs普遍存在的CGM中具有弥散性$α$α$α$ halo，延伸到Halo病毒半径及以后； 3）在电离时期保持中性氢，在$ z> 6 $上的星系$α$排放的强烈变暗表明，这表明了晚期的电源历史。下一代大型望远镜项目将将LY $α$排放数据与HI $ $α$吸收和21厘米无线电数据相结合，这些数据绘制了大多数氢（HI+HII）天然气的绘制，从而揭示了I）通过流出/流入和II）的交换，而II）辐射，与宇宙重新离子相关，与COSMIC REIONICITIAD，Galaxies和CGM/CGM/IGM之间有关。
Hydrogen Lyman-$α$ (Ly$α$) emission has been one of the major observational probes for the high redshift universe, since the first discoveries of high-$z$ Ly$α$ emitting galaxies in the late 1990s. Due to the strong Ly$α$ emission originated by resonant scattering and recombination of the most-abundant element, Ly$α$ observations witness not only HII regions of star formation and AGN but also diffuse HI gas in the circum-galactic medium (CGM) and the inter-galactic medium (IGM). Here we review Ly$α$ sources, and present theoretical interpretations reached to date. We conclude that: 1) A typical Ly$α$ emitter (LAE) at $z\gtrsim 2$ with a $L^*$ Ly$α$ luminosity is a high-$z$ counterpart of a local dwarf galaxy, a compact metal-poor star-forming galaxy (SFG) with an approximate stellar (halo) mass and star-formation rate of $10^{8-9} M_\odot$ ($10^{10-11} M_\odot$) and $1-10 M_\odot$ yr$^{-1}$, respectively; 2) High-$z$ SFGs ubiquitously have a diffuse Ly$α$ emitting halo in the CGM extending to the halo virial radius and beyond; 3) Remaining neutral hydrogen at the epoch of reionization makes a strong dimming of Ly$α$ emission for galaxies at $z>6$ that suggest the late reionization history. The next generation large telescope projects will combine Ly$α$ emission data with HI Ly$α$ absorptions and 21cm radio data that map out the majority of hydrogen (HI+HII) gas, uncovering the exchanges of i) matter by outflow/inflow and ii) radiation, relevant to cosmic reionization, between galaxies and the CGM/IGM.
