COSMOS-3D: Diverse Environments and Hot-dust Signatures among Dusty Star-forming Galaxies at z = 4.9-7.2

@misc{zou2026cosmos3d,
  title = {{COSMOS-3D: Diverse Environments and Hot-dust Signatures among Dusty Star-forming Galaxies at $z$ = 4.9-7.2}},
  author = {Siwei Zou and Manuel Aravena and Shaoze Geng and Romain A Meyer and Jianwei Lyu and Jaclyn B Champagne and Jia-Sheng Huang and Andreas L Faisst and Shuqi Fu and Andrew J Battisti and Hiddo Algera and Caitlin M Casey and Xiaohui Fan and Maximilien Franco and Ghassem Gozaliasl and Linhua Jiang and Koki Kakiichi and Darshan Kakkad and Zihao Li and Lun-Jun Liu and Felix Martinez and Jorge A Zavala and Rasha M Samir},
  howpublished = {HAL},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.35987},
  eprint = {2609.35987},
  archivePrefix = {arXiv},
  url = {https://hal.science/hal-05842245v1},
  note = {CC BY-NC-ND 4.0},
}

TY  - UNPB
TI  - COSMOS-3D: Diverse Environments and Hot-dust Signatures among Dusty Star-forming Galaxies at z = 4.9-7.2
AU  - Siwei Zou
AU  - Manuel Aravena
AU  - Shaoze Geng
AU  - Romain A Meyer
AU  - Jianwei Lyu
AU  - Jaclyn B Champagne
AU  - Jia-Sheng Huang
AU  - Andreas L Faisst
AU  - Shuqi Fu
AU  - Andrew J Battisti
AU  - Hiddo Algera
AU  - Caitlin M Casey
AU  - Xiaohui Fan
AU  - Maximilien Franco
AU  - Ghassem Gozaliasl
AU  - Linhua Jiang
AU  - Koki Kakiichi
AU  - Darshan Kakkad
AU  - Zihao Li
AU  - Lun-Jun Liu
AU  - Felix Martinez
AU  - Jorge A Zavala
AU  - Rasha M Samir
PY  - 2026
DA  - 2026/09/28
PB  - HAL
DO  - 10.48550/arxiv.2609.35987
UR  - https://hal.science/hal-05842245v1
AB  - 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 Hα sample has a median observed, dust-uncorrected SFR_Hα=11.7 M_⊙ yr^−1. Within R=0.5 pMpc, DSFGs have a median δ_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_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 Hα-emitting companions, and their F2100W fluxes are difficult to explain with the 3.3 μm 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.
ER  -