论文标题
$ z \ sim $ 3.4-6.8
Differences and similarities of stellar populations in LAEs and LBGs at $z\sim$ 3.4 - 6.8
论文作者
论文摘要
LAE和LBG的固有恒星种群（SP）之间的差异是理解早期星系形成和进化的关键因素。我们已经运行了一套类似SP的爆发模型，以1,558个来源的样本为$ 3.4 <z <6.8 $，来自调查的高$ z $吸收红色和死源（Shards）（shards）在商品-N场上。这项工作着重于我们样本的三个不同观察性亚家族之间的差异：LAE-LBG，无$ lbgs和Pure Laes。单个和双SP合成光谱用于对SED进行建模，采用贝叶斯信息标准来分析在哪些情况下需要第二个SP。我们发现，使用$ \ sim79 \％$中的单个SP对源进行了很好的建模。最好的模型表明，纯LAE通常是年轻的低质量星系（$ t \ sim26^{+41} _ { - 25} $ myr; $ m _ {\ Mathrm {star}} \ sim5.6^{+sim5.6^{+12.0}恒星形成的爆发。另一方面，无$α$ lbgs需要较旧的sp（$ t \ sim71 \ pm12 $ myr），并且它们更大（$ m _ {\ mathrm {star}} \ sim3.5 \ sim3.5 \ pm1.1 \ pm1.1 \ pm1.1 \ times10^{9} {9} {9} \ m _ _ _ {\ odot} $）。 Lae-LBG似乎是一个子组，更经常需要增加第二个SP，代表了一个旧的巨大星系，在最近的恒星形成剧集中捕获。从每个$ z $上发现的每个亚家族的相对数量都支持从纯LAE和单个SP LAE-LBG到更大的LBG的进化情况。恒星质量功能也被得出，发现随着宇宙时间的增加，$ m^{*} $增加，低质量坡度可能从$ z \ sim6 $增加到$ z \ sim5 $，而没有显着更改为$ z \ sim4 $。此外，我们衍生了Sfr- $ M _ {\ Mathrm {star}} $关系，找到$ \ Mathrm {sfr} \ propto m _ {\ mathrm {star}}^β$ candy的行为，从$ z \ sim4 $ z \ s $ z \ sim \ sim6 $。
The differences between the inherent stellar populations (SPs) of LAEs and LBGs are a key factor in understanding early galaxy formation and evolution. We have run a set of SP burst-like models for a sample of 1,558 sources at $3.4<z<6.8$ from the Survey for High-$z$ Absorption Red and Dead Sources (SHARDS) over the GOODS-N field. This work focuses on the differences between the three different observational subfamilies of our sample: LAE-LBGs, no-Ly$α$ LBGs and pure LAEs. Single and double SP synthetic spectra were used to model the SEDs, adopting a Bayesian information criterion to analyse under which situations a second SP is required. We find that the sources are well modelled using a single SP in $\sim79\%$ of the cases. The best models suggest that pure LAEs are typically young low mass galaxies ($t\sim26^{+41}_{-25}$ Myr; $M_{\mathrm{star}}\sim5.6^{+12.0}_{-5.5}\times10^{8}\ M_{\odot}$), undergoing one of their first bursts of star formation. On the other hand, no-Ly$α$ LBGs require older SPs ($t\sim71\pm12$ Myr), and they are substantially more massive ($M_{\mathrm{star}}\sim3.5\pm1.1\times10^{9}\ M_{\odot}$). LAE-LBGs appear as the subgroup that more frequently needs the addition of a second SP, representing an old and massive galaxy caught in a strong recent star-forming episode. The relative number of sources found from each subfamily at each $z$ supports an evolutionary scenario from pure LAEs and single SP LAE-LBGs to more massive LBGs. Stellar Mass Functions are also derived, finding an increase of $M^{*}$ with cosmic time and a possible steepening of the low mass slope from $z\sim6$ to $z\sim5$ with no significant change to $z\sim4$. Additionally, we have derived the SFR-$M_{\mathrm{star}}$ relation, finding a $\mathrm{SFR}\propto M_{\mathrm{star}}^β$ behaviour with negligible evolution from $z\sim4$ to $z\sim6$.
