论文标题

富含金属的中性气体储层,围绕着$ z = 4 $ jwst/niriss and vlt/use识别的强烈的低质量星系

Metal-Enriched Neutral Gas Reservoir around a Strongly-lensed, Low-mass Galaxy at $z=4$ Identified by JWST/NIRISS and VLT/MUSE

论文作者

Lin, Xiaojing, Cai, Zheng, Zou, Siwei, Li, Zihao, Chen, Zuyi, Bian, Fuyan, Sun, Fengwu, Shu, Yiping, Wu, Yunjing, Li, Mingyu, Li, Jianan, Fan, Xiaohui, Prochaska, J. Xavier, Schaerer, Daniel, Charlot, Stephane, Espada, Daniel, Dessauges-Zavadsky, Miroslava, Egami, Eiichi, Stark, Daniel, Knudsen, Kirsten K., Bruzual, Gustavo, Chevallard, Jacopo

论文摘要

直接观察到$ z \ gtrsim4 $处的低质量,低金属性星系为详细检查电离辐射,气流和金属富集提供了与宇宙重新离子的来源相似的详细检查的必不可少的机会。将James Webb太空望远镜(JWST),VLT/Muse和Alma结合在一起,我们介绍了对强烈的镜头,低质量($ \ $ \ 10^{7.6} $ $ $ {\ rm M} _ \ odot $)的详细观察,at $ z = 3.98 $(另请参见Vanzella et a vanzella等)。我们确定强大的狭窄的蛋白发射,包括civ $λ\ lambda1548,1550 $,heii $ \ lambda1640 $,oiii] $λ\ lambda1661,1666 $,[neiiii]银河系,指示由大型恒星提供动力的金属贫困HII区域($ \ Lessim 0.12 \ {\ rm z} _ \ odot $)。此外,我们检测到与Galaxy相关的金属增强的$α$ System(DLA),其HI列密度为$ n _ {\ rm {hi}}} \大约10^{21.8} $ cm $ $ $^{ - 2} $。相关DLA的金属性可以达到超级太阳金属度($ {\ gtrsim z} _ \ odot $)。此外,多亏了JWST和重力镜头,我们在$ z = 4 $的空间分辨率上介绍了已解决的紫外线($β$)地图,约为100 $ pc,陡峭的紫外线达到$β\ $β\约-2.5 $ -2.5 $左右。我们的观察结果与低红移类似物相结合,表明占主导地位的低质量,低金属性星系可能被高覆盖物的高覆盖层包围,使金属富含金属的中性,中性的云云。这意味着低质量星系的金属富集非常有效,并且进一步支持在低质量星系中,只有一小部分电离辐射可以通过柱密度中性气体的星际或环乳晶通道逸出。

Direct observations of low-mass, low-metallicity galaxies at $z\gtrsim4$ provide an indispensable opportunity for detailed inspection of the ionization radiation, gas flow, and metal enrichment in sources similar to those that reionized the Universe. Combining the James Webb Space Telescope (JWST), VLT/MUSE, and ALMA, we present detailed observations of a strongly lensed, low-mass ($\approx 10^{7.6}$ ${\rm M}_\odot$) galaxy at $z=3.98$ (also see Vanzella et al. 2022). We identify strong narrow nebular emission, including CIV $λ\lambda1548,1550$, HeII $\lambda1640$, OIII] $λ\lambda1661,1666$, [NeIII] $\lambda3868$, [OII] $\lambda3727$, and Balmer series of Hydrogen from this galaxy, indicating a metal-poor HII region ($\lesssim 0.12\ {\rm Z}_\odot$) powered by massive stars. Further, we detect a metal-enriched damped Ly$α$ system (DLA) associated with the galaxy with the HI column density of $N_{\rm{HI}}\approx 10^{21.8}$ cm$^{-2}$. The metallicity of the associated DLA may reach the super solar metallicity (${\gtrsim Z}_\odot$). Moreover, thanks to JWST and gravitational lensing, we present the resolved UV slope ($β$) map at the spatial resolution of $\approx 100$ pc at $z=4$, with steep UV slopes reaching $β\approx -2.5$ around three star-forming clumps. Combining with low-redshift analogs, our observations suggest that low-mass, low-metallicity galaxies, which dominate reionization, could be surrounded by a high covering fraction of the metal-enriched, neutral-gaseous clouds. This implies that the metal enrichment of low-mass galaxies is highly efficient, and further support that in low-mass galaxies, only a small fraction of ionizing radiation can escape through the interstellar or circumgalactic channels with low column-density neutral gas.

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