论文标题
Webb的第一个深领域中早期星系的物理表征SMACS J0723.3-7323
Physical Characterization of Early Galaxies in the Webb's First Deep Field SMACS J0723.3-7323
论文作者
论文摘要
本文重点介绍了SMACS0723视线中JWST NIRCAM成像数据的初始光度分析，旨在识别Redshift $ Z> 7 $的星系。通过应用保守的Lyman突破选择，然后进行光度红移分析和视觉检查，我们确定了四个F090W-Dropout和两个F150W-DropOut来源，其中三个最近在独立的光谱分析中确认至$ Z = 7.666 $，7.665 $，7.665和8.499。然后，我们为样本补充了光度降速式选择，并以$ 7 <z _ {\ rm phot} <13 $确定五个其他候选者。 Nircam图像清楚地解析了所有来源，并揭示了哈勃太空望远镜在先前的成像中未解决/检测到的亚半乳酸成分。我们的光谱能量分布分析表明，所选星系的特征是年轻的恒星种群（中位年龄$ \ sim50 $ myr）的亚极性金属性（$ \ sim0.2 \，z_ \ odot $）和小尘埃衰减（$ a_ {v} \ sim0.5 $）。在某些情况下，我们观察到在F444W频段中捕获的极端HB+[OIII]线，并将其视为颜色过量，这与它们观察到的高星形形成速率表面密度一致。在这项研究中确定的11个来源中有8个出现在至少一项对同一领域的研究之一中（Adams等，Atek等，Donnan等，Harikane等人，Harikane等人，Yan等），这意味着我们选择的高忠诚度。我们与目录中五项研究中提出的所有高级$ z $ Galaxy候选人都在最终列表中讨论了差异的可能原因。
This paper highlights initial photometric analyses of JWST NIRCam imaging data in the sightline of SMACS0723, aiming to identify galaxies at redshift $z>7$. By applying a conservative Lyman-break selection followed by photometric redshift analysis and visual inspection, we identify four F090W-dropout and two F150W-dropout sources, three of which were recently confirmed in an independent spectroscopic analysis to $z=7.663$, 7.665, and 8.499. We then supplement our sample with a photometric-redshift selection, and identify five additional candidates at $7<z_{\rm phot}<13$. The NIRCam images clearly resolve all sources and reveal their sub-galactic components that were not resolved/detected in the previous imaging by Hubble Space Telescope. Our spectral energy distribution analysis reveals that the selected galaxies are characterized by young stellar populations (median age of $\sim50$ Myr) of sub-solar metallicity ($\sim0.2\,Z_\odot$) and little dust attenuation ($A_{V}\sim0.5$). In several cases, we observe extreme Hb+[OIII] lines being captured in the F444W band and seen as color excess, which is consistent with their observed high star formation rate surface density. Eight of the 11 sources identified in this study appear in at least one of the recent studies of the same fields (Adams et al., Atek et al., Donnan et al., Harikane et al., Yan et al.), implying the high fidelity of our selection. We cross-match all high-$z$ galaxy candidates presented in the five studies with our catalog and discuss the possible causes of discrepancy in the final lists.
