TY - JOUR
T1 - ODIN
T2 - Using multiplicity of Lyman-alpha emitters to assess star formation activity in dark matter halos
AU - Candela Cerdosino, M.
AU - Padilla, Nelson
AU - O-Mill, Ana Laura
AU - Gawiser, Eric
AU - Firestone, Nicole M.
AU - Artale, Maria Celeste
AU - Lee, Kyoung Soo
AU - Park, Changbom
AU - Yang, Yujin
AU - Gronwall, Caryl
AU - Guaita, Lucia
AU - Hong, Sungryong
AU - Hwang, Ho Seong
AU - Jeong, Woong Seob
AU - Kumar, Ankit
AU - Lee, Jaehyun
AU - Joshua Lee, Seong Kook
AU - Troncoso Iribarren, Paulina
AU - Zabludoff, Ann
N1 - Publisher Copyright:
© The Authors 2026.
PY - 2026/2/1
Y1 - 2026/2/1
N2 - Aims. We investigate if systems of multiple Lyman-alpha emitters (LAEs) can serve as a proxy for dark matter halo mass, assess how their radiative properties relate to the underlying halo conditions, and explore the physics of star formation activity in LAEs and its relation to possible physically related companions. Methods. We used data from the One-hundred-deg2 DECam Imaging in Narrowbands (ODIN) survey, which targets LAEs in three narrow redshift slices. We identified physically associated LAE multiples in the COSMOS field at z-=-2.4, z-=-3.1, and z-=-4.5, and we used a mock catalog from the IllustrisTNG100 simulation to assess the completeness and contamination affecting the resulting sample of LAE multiples. We then studied their statistical and radiative properties as a function of multiplicity, for which we adopted the term -multiplicity to refer to the number of physically associated LAEs. Results. We find a strong correlation between LAE multiplicity and host halo mass in the mocks, with higher multiplicity systems preferentially occupying more massive halos. In both the ODIN and the mock sample, we find indications that the mean Lyα luminosity and UV magnitude of LAEs in multiples increase with multiplicity. The halo-wide LAE surface brightness densities in Lyα and UV increase with multiplicity, reflecting more compact and actively star-forming environments. The close agreement between the model and ODIN-COSMOS observations supports the validity of the Lyα emission model in capturing key physical processes in LAE environments. Finally, a subhalo-based perturbation-induced star formation model reproduces the minimum subhalo mass distribution in simulations at z-=-2.4, suggesting that local perturbations-rather than the presence of LAE companions-drive star formation activity in these systems. For the higher redshift samples, neighbor perturbations do not seem to be the main driver that triggers star formation.
AB - Aims. We investigate if systems of multiple Lyman-alpha emitters (LAEs) can serve as a proxy for dark matter halo mass, assess how their radiative properties relate to the underlying halo conditions, and explore the physics of star formation activity in LAEs and its relation to possible physically related companions. Methods. We used data from the One-hundred-deg2 DECam Imaging in Narrowbands (ODIN) survey, which targets LAEs in three narrow redshift slices. We identified physically associated LAE multiples in the COSMOS field at z-=-2.4, z-=-3.1, and z-=-4.5, and we used a mock catalog from the IllustrisTNG100 simulation to assess the completeness and contamination affecting the resulting sample of LAE multiples. We then studied their statistical and radiative properties as a function of multiplicity, for which we adopted the term -multiplicity to refer to the number of physically associated LAEs. Results. We find a strong correlation between LAE multiplicity and host halo mass in the mocks, with higher multiplicity systems preferentially occupying more massive halos. In both the ODIN and the mock sample, we find indications that the mean Lyα luminosity and UV magnitude of LAEs in multiples increase with multiplicity. The halo-wide LAE surface brightness densities in Lyα and UV increase with multiplicity, reflecting more compact and actively star-forming environments. The close agreement between the model and ODIN-COSMOS observations supports the validity of the Lyα emission model in capturing key physical processes in LAE environments. Finally, a subhalo-based perturbation-induced star formation model reproduces the minimum subhalo mass distribution in simulations at z-=-2.4, suggesting that local perturbations-rather than the presence of LAE companions-drive star formation activity in these systems. For the higher redshift samples, neighbor perturbations do not seem to be the main driver that triggers star formation.
KW - Galaxies: groups: general
KW - Galaxies: halos
KW - Galaxies: high-redshift
UR - https://www.scopus.com/pages/publications/105028909817
U2 - 10.1051/0004-6361/202557085
DO - 10.1051/0004-6361/202557085
M3 - Article
AN - SCOPUS:105028909817
SN - 0004-6361
VL - 706
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A24
ER -