发表机构
Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS; Departamento de Astronomía, Universidad de Chile; Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales; Millennium Nucleus for Galaxies (MINGAL); School of Astronomy and Space Sciences, University of Chinese Academy of Sciences; Department of Astronomy, University of Geneva; Steward Observatory, University of Arizona; Space Telescope Science Institute; Harvard-Smithsonian Center for Astrophysics; IPAC, California Institute of Technology（中国科学院南美天文中心，国家天文台; 智利大学天文学系; 迭戈帕托利亚斯大学工程与科学学院天体物理研究所; 星系千年核心计划（MINGAL）; 中国科学院大学天文与空间科学学院; 日内瓦大学天文学系; 亚利桑那大学斯图德天文台; 太空望远镜科学研究所; 哈佛-史密森尼天体物理中心; 加州理工学院IPAC）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究利用JWST和ALMA数据研究z=4.9-7.2的18个尘埃星系，发现其环境密度与形态相关，并合星系呈致密环境，而MIRI明亮星系有额外热尘埃成分，暗示早期结构增长的相位依赖图景。
AI 中文摘要
尘埃恒星形成星系（DSFGs）被认为追踪早期大质量暗晕的聚集，但在z>4时，尘埃遮蔽的恒星形成、形态、热尘埃与环境之间的联系仍不清楚。我们结合COSMOS-3D的JWST/NIRCam F444W棱镜光谱、MIRI F1000W/F2100W成像以及来自CRISTAL、CHAMPS、REBELS和A3COSMOS的混合ALMA选择及ALMA后续观测的尘埃星系样本，研究了z=4.9-7.2的18个DSFGs或DSFG候选体。我们使用单独及组合的超密度估计器，将其环境与父样本（光谱确认的发射线样本）及COSMOS-Web测光红移星系样本进行比较。父样本窄线Hα星系的中位观测（未进行尘埃校正）恒星形成速率SFR_Hα=11.7太阳质量/年。在R=0.5物理兆秒差距内，DSFGs的中位δ_spec+phot=0.92^{+0.06}_{-0.16}，而HAEs为0.80^{+0.05}_{-0.04}，在更小尺度上对比更强。最强的致密超密度与并合/相互作用形态相关：并合中的DSFGs在R=0.5物理兆秒差距内达到δ_spec+phot=4.70^{+1.61}_{-1.51}。相反，MIRI明亮的DSFGs并未显示出邻近可见Hα发射伴星数量的增加，且其F2100W通量难以仅用3.3微米PAH特征解释，表明存在额外的热尘埃成分。这些结果与一种可能的相位依赖图景一致，即紧凑的发射线核心、并合驱动的尘埃阶段和MIRI明亮的热尘埃阶段在早期结构增长过程中不必在空间或时间上相同。
英文摘要
Dusty star-forming galaxies (DSFGs) are expected to trace early massive-halo assembly, but the connection between dust-obscured star formation, morphology, hot dust, and environment remains unclear at $z$>4. We combine JWST/NIRCam F444W grism spectroscopy from COSMOS-3D with MIRI F1000W/F2100W imaging and a mixed ALMA-selected and ALMA-followed dusty-galaxy sample from CRISTAL, CHAMPS, REBELS, and A3COSMOS to study 18 DSFGs or DSFG candidates at z=4.9-7.2. We compare their environments with the parent spectroscopically confirmed emission-line sample and the COSMOS-Web photo-z galaxy sample using separate and combined overdensity estimators. The parent narrow-line H$α$ sample has a median observed, dust-uncorrected ${\rm SFR}_{\rm Hα}=11.7 M_\odot~{\rm yr^{-1}}$. Within R=0.5 pMpc, DSFGs have a median $δ_{\rm spec+phot}=0.92^{+0.06}_{-0.16}$, compared with $0.80^{+0.05}_{-0.04}$ for HAEs, with a stronger contrast on smaller scales. The strongest compact overdensities are associated with merger/interacting morphology: merging DSFGs reach $δ_{\rm spec+phot}=4.70^{+1.61}_{-1.51}$ within R=0.5 pMpc. In contrast, MIRI-bright DSFGs do not show an enhanced number of nearby visible H$α$-emitting companions, and their F2100W fluxes are difficult to explain with the 3.3 $μ$m PAH feature alone, suggesting an additional hot-dust component. These results are consistent with a possible phase-dependent picture in which the compact line-emitter core, merger-driven dusty phase, and MIRI-bright hot-dust phase need not be spatially or temporally identical during early structure growth.
Comments31 pages, 8 figures, and 2 tables in the main text. Revised following the first referee report
