大规模第三星族星系靠近GN-z11类似体：重子-暗物质流速度的作用
Massive Population III Galaxies Near a GN-z11 Analog: The Role of the Baryon-Dark Matter Streaming Velocity
- University of Toledo（托莱多大学）
- Columbia University（哥伦比亚大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过半解析模型与N体模拟，发现靠近GN-z11类似体的高密度区域存在晚期形成的第三星族星系，其形成受重子-暗物质流速度显著影响，高流速度可促进此类星系出现，并可能孕育重型黑洞种子。
AI中文摘要：
最近，詹姆斯·韦布空间望远镜（JWST）探测到Hebe，一个第三星族（Pop III）候选体，其投影距离约为3千秒差距，位于质量为$z=10.6$的星系GN-z11附近。这提出了一个问题：在高质量高红移星系附近是否预期存在第三星族恒星形成，还是早期金属增丰会阻止其发生。我们通过一个半解析模型来解决这一问题，该模型描述了第三星族和金属增丰恒星形成，并将其应用于一个围绕GN-z11类似体的高过密区域的放大N体模拟。放大区域解析了第一代恒星形成的最小暗物质晕。我们发现，与典型的平均密度环境相比，第三星族和金属增丰恒星形成都更早发生，且恒星形成率密度更高。最小暗物质晕中的大部分第三星族恒星形成在$z\sim15$之前结束；然而，我们识别出一个不同的晚期形成第三星族星系群体，它们在中心星系附近形成。这些系统的恒星形成因中心GN-z11类似体的电离反馈而延迟，并经历约${\sim}10$至$100~J_{21}$的莱曼-沃纳（LW）强度，可能导致类似于Hebe的大规模第三星族星暴。有趣的是，这些第三星族星系的丰度强烈依赖于重子-暗物质流速度$v_{\rm bc}$，因为较高的流速度使暗物质晕能够更长时间保持化学纯净。对于$v_{\rm bc}=0$，这些晚期形成的第三星族源均不出现，而在高$v_{\rm bc}$时则形成许多。对预期流速度分布进行平均后，我们预测在$z\sim11$处需要调查约四个类似GN-z11的星系才能预期发现一个这样的源。我们还注意到，这些环境可能为重型黑洞种子提供自然的形成场所。
英文摘要：
Recently the James Webb Space Telescope (JWST) detected Hebe, a Population III (Pop III) candidate located ${\sim}3$ kpc in projection from the massive $z=10.6$ galaxy GN-z11. This raises the question of whether Pop III star formation is expected in the vicinity of massive high-redshift galaxies or whether it would be prevented by early metal enrichment. We address this with a semi-analytic model of Pop III and metal-enriched star formation applied to a zoom-in N-body simulation of a highly overdense region surrounding a GN-z11 analog. The zoom-in region resolves the minihalos where the first stars form. We find that Pop III and metal-enriched star formation both occur earlier, and with a higher star formation rate density, than in a typical mean-density environment. The majority of Pop III star formation in minihalos ends by $z\sim15$; however, we identify a distinct population of late-forming Pop III galaxies that form near the central galaxy. These systems have their star formation delayed due to ionizing feedback from the central GN-z11 analog and experience a Lyman-Werner (LW) intensity of ${\sim}10$ - $100~J_{21}$, potentially leading to massive Pop III starbursts similar to Hebe. Interestingly, the abundance of these Pop III galaxies depends strongly on the baryon-dark matter streaming velocity, $v_{\rm bc}$, because a higher streaming velocity allows halos to remain chemically pristine for longer. None of these late-forming Pop III sources occur for $v_{\rm bc}=0$, while many form at high $v_{\rm bc}$. Averaging over the expected distribution of streaming velocities, we predict that of order four GN-z11-like galaxies would need to be surveyed at $z\sim11$ to expect to find one such source. We also note these environments may provide a natural formation site for heavy black hole seeds.
