AI 中文总结
研究宇宙正午时棒状星系EGS - 24154，通过分析其近红外光谱数据，推导恒星族群性质，发现棒区域恒星形成荒漠及AGN反馈作用，证明恒星棒是盘状星系早期演化关键驱动因素，呼吁修订相关星系形成模型。
AI 中文摘要
詹姆斯·韦布空间望远镜（JWST）的观测揭示了宇宙正午时意外大量的棒状星系。然而，这些早期棒的物理性质几乎未受约束，因其对高红移盘状星系结构演化的影响。在这项工作中，我们推导了红移\(z = 1.17\)的棒旋星系EGS - 24154的恒星族群。首先，研究恒星棒在星系早期组装历史和结构演化中的作用。其次，研究星际介质性质以揭示与中央超大质量黑洞的相互作用。通过全光谱拟合分析EGS - 24154的中分辨率近红外光谱仪/积分场光谱数据，得出光度和质量加权年龄及金属丰度。重构空间分辨的恒星形成历史，分析多条发射线推导星际介质的电离机制，表征EGS - 24154的动力学，并约束AGN发射的双锥外流性质。EGS - 24154是重子主导、富含气体的盘状星系，在宇宙约20亿岁时增长了超过90%的恒星质量。发现棒的恒星族群在\(z\sim5\)开始形成，与恒星盘开始组装的时间相符。在棒区域观察到恒星形成荒漠，其导致恒星形成在数十亿年中淬灭。进而解释AGN的反馈阻止了中央质量聚集的增长，使恒星棒在尺寸和强度上得以增长。在对红移大于1的棒状盘状星系的空间分辨恒星族群的首次研究中，证明了恒星棒是盘状星系早期结构和动力学演化的关键驱动因素。特别是，我们的结果要求修订早期重子主导、富含气体的盘状星系中盘和棒形成的大多数模型。
英文摘要
Observations with the JWST revealed an unexpected abundance of barred galaxies at Cosmic Noon. However, the physical properties of these early bars are almost unconstrained, as it is their impact in the structural evolution of high-z disc galaxies. In this work, we derived the stellar populations of EGS-24154, a barred spiral galaxy at $z=1.17$. First, we investigated the role of the stellar bar in the early assembly history and structural evolution of the galaxy. Second, we studied the properties of the interstellar medium to shed light on the interplay with the central supermassive black hole. We analysed medium-resolution NIRSpec/IFS data of EGS-24154 through full-spectral fitting and derived light and mass-weighted ages and metallicities. We then reconstructed the spatially-resolved SFH, derived the ionizing mechanisms of the interstellar medium analysing several emission lines, characterized the dynamics of EGS-24154, and constrained the properties of a biconical outflow launched by the AGN. EGS-24154 is a baryon-dominated, gas-rich disc galaxy, which grew more than 90% of its stellar mass when the Universe was ~2 Gyr old. We found that the stellar population of the bar started to form at $z\sim5$, compatibly to the time when the stellar disc started to assemble. We observed a star formation desert in the bar region, which is responsible for quenching star formation over several Gyr. We then interpreted that the feedback from the AGN prevented the growth of central mass concentration, allowing the stellar bar to grow in size and strength. In this first study of spatially-resolved stellar populations of a barred disc galaxy at $z>1$, we demonstrated how stellar bars are key drivers of the early structural and dynamical evolution of disc galaxies. In particular, our results call for a revision of most models of disc and bar formation in early baryon-dominated, gas-rich disc galaxies.
Comments13 pages, 8 figures. Submitted to A&A. Comments are welcome
