论文标题
JWST揭示的SMACS 0723中五个Z> 5 Z> 5发射线星系的金属性
Metallicities of Five z > 5 Emission-Line Galaxies in SMACS 0723 Revealed by JWST
论文作者
论文摘要
JWST对镜头群集SMACS J0723.3-7327的早期发布观察结果使光谱镜对高红色的宇宙进行了前所未有的光谱外观。这些观察结果揭示了Z> 5的五个星系。所有五个都有可检测的[OIII] 4363线发射，表明这些星系具有高温和低金属性，并且它们是高度恒星形成的。在最近的工作中，已经使用各种技术研究了这五个星系的金属性。在这里，我们总结并比较了这些先前的结果，并使用改进的方法学对金属性进行了自己的测量，从而优化了发射线的提取。特别是，我们使用同时的线路拟合和固定的Balmer降低校正，以及对2D光谱中发射线的新型足迹测量，以产生对校准和系统效应不太敏感的较高的保真度线比。然后，我们将金属性与H-beta等效宽度较高的Z <1星系的金属性进行比较，发现它们可能是良好的类似物。最后，我们估计与宇宙年龄相比，Z〜8的JWST星系很年轻。
JWST's Early Release Observations of the lensing cluster SMACS J0723.3-7327 have given an unprecedented spectroscopic look into the high-redshift universe. These observations reveal five galaxies at z > 5. All five have detectable [OIII]4363 line emission, indicating that these galaxies have high temperatures and low metallicities and that they are highly star forming. In recent work, the metallicities of these five galaxies have been studied using various techniques. Here we summarize and compare these previous results, as well as perform our own measurements of the metallicities using improved methodologies that optimize the extraction of the emission lines. In particular, we use simultaneous line fitting and a fixed Balmer decrement correction, as well as a novel footprint measurement of the emission lines in the 2D spectra, to produce higher fidelity line ratios that are less sensitive to calibration and systematic effects. We then compare our metallicities to those of z < 1 galaxies with high rest-frame equivalent widths of H-beta, finding that they may be good analogs. Finally, we estimate that the JWST galaxies out to z ~ 8 are young compared to the age of the universe.
