论文标题
Glass-JWST的早期结果。 IV：低质量$ z \ sim3 $ Galaxy与Niriss的空间分辨金属性
Early results from GLASS-JWST. IV: Spatially resolved metallicity in a low-mass $z\sim3$ galaxy with NIRISS
论文作者
论文摘要
我们报告了使用James Webb太空望远镜（JWST）测量的遥远星系的第一座气相金属图。我们使用玻璃早期发行科学程序获得的Niriss nirss slits slitsscoppy，在重力镜头的星系中以$ z = 3.06 $落后于Abell 2744 Galaxy群集，在重力镜头的星系中以空间来解决剩余的光学Nebular发射线。这个星系（称为玻璃-Zgrad1）具有出色的质量$ \ sim10^{8.6} m_ \ odot $，瞬时星形形成率$ \ sim8.6 $ $ $ $ $ m_ \ odot $/yr（均校正了透镜放大倍率）和全球金属金属solar。从其发射线图（[O III]，H $β$，H $γ$，[NE III]和[O II]）中，我们使用良好的前向模型贝叶斯推断方法得出了其气相金属性的空间分布。 JWST/NIRIS的精致分辨率和灵敏度，再加上镜头放大倍率，使我们能够以$ \ gtrsim $ 50的分辨率元素来解决此$ z \ sim3 $ dwarf Galaxy，并具有足够的信号，这是不可能的分析。我们发现，玻璃-Zgrad1的径向金属梯度强烈反转（即阳性）：$δ\ log（{\ rm o/h}）/Δr$ = $ 0.165 \ pm0.023 $ $ $ $ $ $ \ $ \ mathrm {dex〜kpc^kpc^{ - 1}} $。这种倒置的梯度可能是由于附近的巨大的（$ \ sim $ 15 kpc预测）的银河系引起的潮汐扭矩，这可能会导致金属贫困气体的流入到玻璃-Zgrad1的中央区域。这些第一个结果展示了JWST宽场无slitss slit无光谱模式的功能，以解决低质量星系的质量组装和化学富集在宇宙之星形成的峰值时期（$ z \ gtrsim2 $）中。在这些红移时达到质量$ \ lyssim 10^9〜m_ \ odot $对于约束银河反馈和环境的影响特别有价值，并且只有JWST的新功能才有可能。
We report the first gas-phase metallicity map of a distant galaxy measured with the James Webb Space Telescope (JWST). We use the NIRISS slitless spectroscopy acquired by the GLASS Early Release Science program to spatially resolve the rest-frame optical nebular emission lines in a gravitationally lensed galaxy at $z=3.06$ behind the Abell 2744 galaxy cluster. This galaxy (dubbed GLASS-Zgrad1) has stellar mass $\sim10^{8.6} M_\odot$, instantaneous star formation rate $\sim8.6$ $M_\odot$/yr (both corrected for lensing magnification), and global metallicity one-fourth solar. From its emission line maps ([O III], H$β$, H$γ$, [Ne III], and [O II]) we derive its spatial distribution of gas-phase metallicity using a well-established forward-modeling Bayesian inference method. The exquisite resolution and sensitivity of JWST/NIRISS, combined with lensing magnification, enable us to resolve this $z\sim3$ dwarf galaxy in $\gtrsim$50 resolution elements with sufficient signal, an analysis hitherto not possible. We find that the radial metallicity gradient of GLASS-Zgrad1 is strongly inverted (i.e. positive): $Δ\log({\rm O/H})/Δr$ = $0.165\pm0.023$ $\mathrm{dex~kpc^{-1}}$. This inverted gradient may be due to tidal torques induced by a massive nearby ($\sim$15 kpc projected) galaxy, which can cause inflows of metal-poor gas into the central regions of GLASS-Zgrad1. These first results showcase the power of JWST wide-field slitless spectroscopic modes to resolve the mass assembly and chemical enrichment of low-mass galaxies in and beyond the peak epoch of cosmic star formation ($z\gtrsim2$). Reaching masses $\lesssim 10^9~M_\odot$ at these redshifts is especially valuable to constrain the effects of galactic feedback and environment, and is possible only with JWST's new capabilities.
