韦布空间望远镜（JWST）/NIRSpec IFU 揭示了 z = 9.31 处一个动力学热相互作用星系中多样的电离气体条件

本文利用韦布空间望远镜（JWST）的高谱分辨率观测，对 z = 9.31 处的相互作用星系 Gz9p3 进行了空间和光谱分辨研究。研究发现该星系核心区与尾部在电子密度、金属丰度和比恒星形成率（sSFR）方面存在显著差异，且系统表现出动力学热状态及银河喷泉现象。

arXiv:2608.16996v1 Announce Type: new Abstract: We present a spatially and spectrally resolved study of an interacting galaxy, Gz9p3 at $z=9.31$, using the James Webb Space Telescope NIRSpec/G395H IFU observation with high-spectral resolution ($R\approx 2700$) mode. Gz9p3 consists of two sub-regions (`core' and `tail'), which show stark contrast in their physical properties. The HII regions in the core are characterized by high electron density ($n_{e}\gtrsim2900$ cm$^{-3}$), low gas-phase metallicity ($0.25$ dex below the mass-metallicity relation), and yet relatively low specific star formation rate (sSFR) among the system. On the other hand, the tail exhibits low electron density ($n_{e}<70$ cm$^{-3}$), relatively high gas-phase metallicity that is consistent with the mass-metallicity relation, and high sSFR. The integrated spectrum thus shows the properties inbetween these two regions. No evidence of ordered rotation in ionized gas is found, suggesting that Gz9p3 is a dynamically hot system. Finally, we find ionized gas outflows characterized by the secondary [OIII]5007 line component throughout most of the system. The outflow velocity is below the escape velocity, making Gz9p3 one of the first galactic systems experiencing a galactic fountain. Overall, our findings indicate that this system is in a phase in which the pristine gas is falling efficiently into the