Bibliographic Details
| Title: |
Searching for nearby diffuse dwarf galaxies in the COSMOS field |
| Authors: |
Dong Dong Shi, Xian Zhong Zheng, Zhizheng Pan, Yu Luo, Hongxia Deng, Qunzhi Hua, Xinyu Luo, Qiming Wu |
| Source: |
Frontiers in Astronomy and Space Sciences, Vol 12 (2025) |
| Publisher Information: |
Frontiers Media S.A., 2025. |
| Publication Year: |
2025 |
| Collection: |
LCC:Astronomy
LCC:Geophysics. Cosmic physics |
| Subject Terms: |
galaxy formation, galaxy evolution, COSMOS field, ultra-diffuse galaxies, dwarf galaxies, extragalactic astronomy, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809 |
| More Details: |
It remains challenging to systematically survey nearby diffuse dwarf galaxies and address the formation mechanism of this population distinguishing from regular ones. We carry out a pilot search for these galaxies in the COSMOS field using the deep HST/F814W imaging data. We report three diffuse dwarf galaxies satisfying the criteria: (1) redshift z1.′′0, and (3) central surface brightness μ0>24 mag arcsec−2. Two of the three galaxies, COSMOS-UDG1 and COSMOS-UDG2, are recognized as ultra-diffuse galaxies (UDGs) with redshift z=0.130 and 0.049, respectively. The third galaxy, COSMOS-dw1, is spectroscopically confirmed as a dwarf galaxy at z=0.004. We derive the physical properties through fitting their spectral energy distributions (SEDs) extracted from deep multiwavelength observations. COSMOS-dw1 has a stellar mass of 5.6−2.7+2.5×106M⊙, harboring neutral hydrogen gas of mass 4.90±0.90×106M⊙, hinting that this galaxy may be in the nascent stages of quenching. The estimated dynamical mass of 3.4×107 M⊙ further suggests that COSMOS-dw1 is predominantly of dark matter. COSMOS-UDG1 and COSMOS-UDG2 exhibit comparable stellar masses of ∼2×108M⊙. Notably, COSMOS-UDG1 is younger and more metal-rich than COSMOS-UDG2 and COSMOS-dw1. Conversely, COSMOS-UDG2 and COSMOS-dw1 have similar stellar metallicities, yet COSMOS-UDG2 is older than COSMOS-dw1. All three galaxies adhere to the stellar mass-metallicity relation (MZR) for dwarf galaxies in the local Universe, implying they belong to the dwarf galaxy population. |
| Document Type: |
article |
| File Description: |
electronic resource |
| Language: |
English |
| ISSN: |
2296-987X |
| Relation: |
https://www.frontiersin.org/articles/10.3389/fspas.2025.1560380/full; https://doaj.org/toc/2296-987X |
| DOI: |
10.3389/fspas.2025.1560380 |
| Access URL: |
https://doaj.org/article/c114e49919e54cec86c9afa657b0c9bb |
| Accession Number: |
edsdoj.114e49919e54cec86c9afa657b0c9bb |
| Database: |
Directory of Open Access Journals |
