Searching for nearby diffuse dwarf galaxies in the COSMOS field

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 dwa...

Full description

Saved in:
Bibliographic Details
Main Authors: Dong Dong Shi, Xian Zhong Zheng, Zhizheng Pan, Yu Luo, Hongxia Deng, Qunzhi Hua, Xinyu Luo, Qiming Wu
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-03-01
Series:Frontiers in Astronomy and Space Sciences
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fspas.2025.1560380/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850235947534254080
author Dong Dong Shi
Xian Zhong Zheng
Zhizheng Pan
Yu Luo
Hongxia Deng
Qunzhi Hua
Xinyu Luo
Qiming Wu
author_facet Dong Dong Shi
Xian Zhong Zheng
Zhizheng Pan
Yu Luo
Hongxia Deng
Qunzhi Hua
Xinyu Luo
Qiming Wu
author_sort Dong Dong Shi
collection DOAJ
description 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 z<0.2, (2) effective radius re>1.′′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.
format Article
id doaj-art-c114e49919e54cec86c9afa657b0c9bb
institution OA Journals
issn 2296-987X
language English
publishDate 2025-03-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Astronomy and Space Sciences
spelling doaj-art-c114e49919e54cec86c9afa657b0c9bb2025-08-20T02:02:05ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2025-03-011210.3389/fspas.2025.15603801560380Searching for nearby diffuse dwarf galaxies in the COSMOS fieldDong Dong Shi0Xian Zhong Zheng1Zhizheng Pan2Yu Luo3Hongxia Deng4Qunzhi Hua5Xinyu Luo6Qiming Wu7Center for Fundamental Physics, School of Mechanics and Optoelectronic Physics, Anhui University of Science and Technology, Huainan, ChinaTsung-Dao Lee Institute and Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education, Shanghai Jiao Tong University, Shanghai, ChinaPurple Mountain Observatory, Chinese Academy of Sciences, Nanjing, Jiangsu, ChinaDepartment of Physics, School of Physics and Electronics, Hunan Normal University, Changsha, ChinaCenter for Fundamental Physics, School of Mechanics and Optoelectronic Physics, Anhui University of Science and Technology, Huainan, ChinaCenter for Fundamental Physics, School of Mechanics and Optoelectronic Physics, Anhui University of Science and Technology, Huainan, ChinaCenter for Fundamental Physics, School of Mechanics and Optoelectronic Physics, Anhui University of Science and Technology, Huainan, ChinaCenter for Fundamental Physics, School of Mechanics and Optoelectronic Physics, Anhui University of Science and Technology, Huainan, ChinaIt 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 z<0.2, (2) effective radius re>1.′′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.https://www.frontiersin.org/articles/10.3389/fspas.2025.1560380/fullgalaxy formationgalaxy evolutionCOSMOS fieldultra-diffuse galaxiesdwarf galaxiesextragalactic astronomy
spellingShingle Dong Dong Shi
Xian Zhong Zheng
Zhizheng Pan
Yu Luo
Hongxia Deng
Qunzhi Hua
Xinyu Luo
Qiming Wu
Searching for nearby diffuse dwarf galaxies in the COSMOS field
Frontiers in Astronomy and Space Sciences
galaxy formation
galaxy evolution
COSMOS field
ultra-diffuse galaxies
dwarf galaxies
extragalactic astronomy
title Searching for nearby diffuse dwarf galaxies in the COSMOS field
title_full Searching for nearby diffuse dwarf galaxies in the COSMOS field
title_fullStr Searching for nearby diffuse dwarf galaxies in the COSMOS field
title_full_unstemmed Searching for nearby diffuse dwarf galaxies in the COSMOS field
title_short Searching for nearby diffuse dwarf galaxies in the COSMOS field
title_sort searching for nearby diffuse dwarf galaxies in the cosmos field
topic galaxy formation
galaxy evolution
COSMOS field
ultra-diffuse galaxies
dwarf galaxies
extragalactic astronomy
url https://www.frontiersin.org/articles/10.3389/fspas.2025.1560380/full
work_keys_str_mv AT dongdongshi searchingfornearbydiffusedwarfgalaxiesinthecosmosfield
AT xianzhongzheng searchingfornearbydiffusedwarfgalaxiesinthecosmosfield
AT zhizhengpan searchingfornearbydiffusedwarfgalaxiesinthecosmosfield
AT yuluo searchingfornearbydiffusedwarfgalaxiesinthecosmosfield
AT hongxiadeng searchingfornearbydiffusedwarfgalaxiesinthecosmosfield
AT qunzhihua searchingfornearbydiffusedwarfgalaxiesinthecosmosfield
AT xinyuluo searchingfornearbydiffusedwarfgalaxiesinthecosmosfield
AT qimingwu searchingfornearbydiffusedwarfgalaxiesinthecosmosfield