标题： 小红点作为直接塌缩黑洞育婴室 显示英文标题

标题： Little Red Dots as Direct-collapse Black Hole Nurseries

摘要： 詹姆斯·韦布空间望远镜最近在大爆炸后第一个十亿年内发现了一群大质量黑洞（BHs）。 在这些高红移BH候选者中，观测已识别出一类活动星系核候选者，被称为小红点（LRDs），它们具有异常紧凑的气体储库和特殊的光谱特征。 LRDs在红移z<8时明显出现，其丰富度在z<5时下降。 近期的理论研究探讨了LRDs与早期宇宙中重质量BH种子形成的联系，例如直接坍缩黑洞（DCBHs）。 在这里，我们展示了MELIORA宇宙学流体动力学模拟的初步运行结果，在其中我们实现了对DCBH形成准确的模型，考虑了目标宿主晕中的Lyman-Werner辐射场和质量流入率。 我们的目标是测试DCBH形成是否可能导致类似于LRDs假设的系统。 我们发现模拟中新形成的DCBH群体在z<6时表现出急剧下降，类似于LRDs的出现，这主要由减少的流入量驱动。 DCBH的诞生与一次显著的气体紧缩事件相关，随后是在其诞生后2亿年内的强烈发光阶段，接着是在这些非常晕中形成的第一代PopIII恒星。 如果这些DCBH育婴室与LRDs有关，那么就可以解释它们来自X射线和热尘埃的弱发射。 显示英文摘要

摘要： The James Webb Space Telescope recently uncovered a population of massive black holes (BHs) in the first billion years after the Big Bang. Among these high-redshift BH candidates, observations have identified a class of active galactic nuclei candidates, dubbed Little Red Dots (LRDs), with extraordinarily compact gas reservoirs and peculiar spectral features. LRDs clearly emerge at redshift z<8 and their abundance declines by z<5. Recent theoretical studies have explored the link between LRDs and the formation of heavy BH seeds in the early Universe, such as direct-collapse BHs (DCBHs). Here we present results from preliminary runs for the MELIORA cosmological hydrodynamical simulations, where we implement an accurate model for DCBH formation, accounting for the Lyman-Werner radiation field and mass-inflow rates in the target host haloes. We aim to test whether or not DCBH formation could lead to systems resembling those hypothesized for LRDs. We find that the population of newly formed DCBHs in the simulations exhibits a steep decline at z<6, akin to the emergence of LRDs, primarily driven by reduced inflows. The birth of DCBHs is associated with a significant gas compaction event, followed by a phase of intense luminosity in the 200 Myr after their birth, and subsequently by the formation of the first PopIII stars in these very haloes. If these DCBHs nurseries are associated with LRDs, then it could explain their weak emission from X-rays and hot dust.