论文标题
Lyman-Alpha从低质量，紧凑，高红移星系中逃脱
Lyman-Alpha Escape from Low-Mass, Compact, High-Redshift Galaxies
论文作者
论文摘要
我们研究了27个光谱镜确认的恒星种群和大小对LY $α$逃生的影响，并在NOAO深宽田间调查的Boötes地区的七个领域中，在Z $ \ $ 2.65的Z $ \ $ \ $ 2.65中进行了大约2.65美元的影响。我们使用Deep $ HST $/WFC3成像来补充基于地面的观测值并推断关键的星系属性。与在类似红移的典型星形星系（SFG）相比，Laes的质量较小（$ M _ {\ star} \大约10^{7} -10^{9} {9} 〜m _ {\ odot} $），年轻（年龄$ \ \ \ 1 gyr），较小的（$ 1 gyr），较小的（$ 1 gyr），$ r _ = $ c <$ c <$ 1 kp <$ {e = （e（b $ - $ v）$ \ le $ 0.26 mag），但具有可比的恒星形成率（sfrs $ \ of 1-100〜m _ {\ odot} {\ rm yr yr^{ - 1}}} $）。样本中的某些LAE可能是非常年轻的星系，具有低蛋白金属度（$ {\ rm z_ {neb} \ Lessim 0.2 z _ {\ odot}} $）和/或高电离参数（$ \ log {$ \ log {（\ rm u）} \ gtrsim -2.4 $ -2.4 $）。在先前的研究中，我们通过计算$σ_ {\ rm sfr} $ $σ_{\ rm ssfr} $ $σ_{\ rm sfr} $，研究了恒星形成和重力电位对LY $α$逃生的浓度对LY $α$逃生的影响。对于给定的$σ_ {\ rm sfr} $，对于较低恒星质量的Laes来说，LY $α$逃生分数更高。与SFG相比，LAES平均具有更高的$σ_ {\ rm ssfr} $。我们的结果表明，在低重力电势下紧凑的恒星形成可以使$α$光子的逃脱的条件适合。这些结果对LY $α$辐射转移的物理和可能对宇宙回离产生重大贡献的星系类型具有重要意义。
We investigate the effects of stellar populations and sizes on Ly$α$ escape in 27 spectroscopically confirmed and 35 photometric Lyman-Alpha Emitters (LAEs) at z $\approx$ 2.65 in seven fields of the Boötes region of the NOAO Deep Wide-Field Survey. We use deep $HST$/WFC3 imaging to supplement ground-based observations and infer key galaxy properties. Compared to typical star-forming galaxies (SFGs) at similar redshifts, the LAEs are less massive ($M_{\star} \approx 10^{7} - 10^{9}~M_{\odot}$), younger (ages $\lesssim$ 1 Gyr), smaller ($r_{e} <$ 1 kpc), less dust-attenuated (E(B$-$V) $\le$ 0.26 mag), but have comparable star-formation-rates (SFRs $\approx 1 - 100~M_{\odot} {\rm yr^{-1}}$). Some of the LAEs in the sample may be very young galaxies having low nebular metallicities (${\rm Z_{neb} \lesssim 0.2 Z_{\odot}}$) and/or high ionization parameters ($\log{(\rm U)} \gtrsim -2.4$). Motivated by previous studies, we examine the effects of the concentration of star formation and gravitational potential on Ly$α$ escape, by computing star-formation-rate surface density, $Σ_{\rm SFR}$ and specific star-formation-rate surface density, $Σ_{\rm sSFR}$. For a given $Σ_{\rm SFR}$, the Ly$α$ escape fraction is higher for LAEs with lower stellar masses. LAEs have higher $Σ_{\rm sSFR}$ on average compared to SFGs. Our results suggest that compact star formation in a low gravitational potential yields conditions amenable to the escape of Ly$α$ photons. These results have important implications for the physics of Ly$α$ radiative transfer and for the type of galaxies that may contribute significantly to cosmic reionization.
