论文标题
SMACS 0723中JWST/NIRSPEC光谱的宇宙黎明时发射线星系的物理条件
The Physical Conditions of Emission-Line Galaxies at Cosmic Dawn from JWST/NIRSpec Spectroscopy in the SMACS 0723 Early Release Observations
论文作者
论文摘要
我们介绍了SMACS 0723早期版本观察结果中JWST近进型光谱仪（NIRSPEC）观察到的五$ z> 5 $星系的五个$ z> 5 $星系的休息框光发射线的比率测量值。我们在NIRSPEC管道减少产品中添加了几个质量控制和后处理步骤，以确保在当前减少版本的降低版本的分光光度计；与文献中的$ z \ sim3 $星系相比，$ z> 5 $星系具有相似的[oiii] $λ$ 5008/h $β$比率，相似[oiii] $λ$ 4364/h $γ$比率，并且更高（$ \ sim $ 0.5 dex）[neiiii] $ 3870 $ 3700. $ 3870 $ 3870 $ 370 $ 3700。我们将观察结果与映射v光电离模型进行比较，并发现所测量的[NEIII] $ 3870/[OII] $λ$ 3728，[OIII] $λ$ 4364 $ 4364/H $γ$，[OIII] $ 5008/h $ 5008/h $ 5008/h $β$β$ susission-has intercions Intercion and Intercion是一致的。 （$ \ log（q）\ simeq 8-9 $，cm〜s $^{ - 1} $的单位，低金属（$ z/z_ \ odot \ odot \ lyseSim 0.2 $）和非常高的压力（$ \ log（p/k）\ simeq 8-9 $，cm $ $ $^{ - 3} $）。 [OIII] $λ$ 4364/H $γ$和[OIII] $λ$（4960+5008）/H $β$线比的组合表明非常高的电子温度为$ 4.1 <\ log log（t_e/{t_e/{\ rm k}）将低红移校准应用于``$ t_e $ based''金属。这些观察结果代表了宇宙黎明星系中星际介质的物理条件的诱人新观点。
We present rest-frame optical emission-line flux ratio measurements for five $z>5$ galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in the SMACS 0723 Early Release Observations. We add several quality-control and post-processing steps to the NIRSpec pipeline reduction products in order to ensure reliable relative flux calibration of emission lines that are closely separated in wavelength, despite the uncertain \textit{absolute} spectrophotometry of the current version of the reductions. Compared to $z\sim3$ galaxies in the literature, the $z>5$ galaxies have similar [OIII]$λ$5008/H$β$ ratios, similar [OIII]$λ$4364/H$γ$ ratios, and higher ($\sim$0.5 dex) [NeIII]$λ$3870/[OII]$λ$3728 ratios. We compare the observations to MAPPINGS V photoionization models and find that the measured [NeIII]$λ$3870/[OII]$λ$3728, [OIII]$λ$4364/H$γ$, and [OIII]$λ$5008/H$β$ emission-line ratios are consistent with an interstellar medium that has very high ionization ($\log(Q) \simeq 8-9$, units of cm~s$^{-1}$), low metallicity ($Z/Z_\odot \lesssim 0.2$), and very high pressure ($\log(P/k) \simeq 8-9$, units of cm$^{-3}$). The combination of [OIII]$λ$4364/H$γ$ and [OIII]$λ$(4960+5008)/H$β$ line ratios indicate very high electron temperatures of $4.1<\log(T_e/{\rm K})<4.4$, further implying metallicities of $Z/Z_\odot \lesssim 0.2$ with the application of low-redshift calibrations for ``$T_e$-based'' metallicities. These observations represent a tantalizing new view of the physical conditions of the interstellar medium in galaxies at cosmic dawn.
