The Physical Properties of Star-forming Galaxies with Strong [O III] Lines at z = 3.25
Abstract
We present an analysis of physical properties of 34 [O III] emission-line galaxies (ELGs) at z = 3.254 ± 0.029 in the Extended Chandra Deep Field South (ECDFS). These ELGs are selected from deep narrow H2S(1) and broad K s imaging of 383 arcmin2 obtained with CFHT/WIRCam. We construct spectral energy distributions (SEDs) from U to K s to derive the physical properties of ELGs. These [O III] ELGs are identified as starburst galaxies with strong [O III] lines of L OIII ~ 1042.6-1044.2 erg s-1 and have stellar masses of M * ~ 109.0-1010.6 M ⊙ and star formation rates of ~10-210 M ⊙ yr-1. Our results show that 24% of our sample galaxies are dusty with A V > 1 mag and EW([O III])rest ~ 70-500 Å, which are often missed in optically selected [O III] ELG samples. Their rest-frame UV and optical morphologies from HST/ACS and HST/WFC3 deep imaging reveal that these [O III] ELGs are mostly multiple-component systems (likely mergers) or compact. And 20% of them are nearly invisible in the rest-frame UV owing to heavy dust attenuation. Interestingly, we find that our sample ELGs reside in an overdensity consisting of two components: one southeast (SE) with an overdensity factor of δ gal ~ 41 over a volume of 133 cMpc3, and the other northwest (NW) with δ gal ~ 38 over a volume of 103 cMpc3. The two overdense substructures are expected to be virialized at z = 0 with a total mass of ~ 1.1 × 1015 M ⊙ and ~ 4.8 × 1014 M ⊙ and probably merge into a Coma-like galaxy cluster.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2022
- DOI:
- 10.3847/1538-4357/ac7392
- arXiv:
- arXiv:2205.13310
- Bibcode:
- 2022ApJ...933...50W
- Keywords:
-
- Galaxy formation;
- Galaxy evolution;
- High-redshift galaxies;
- 595;
- 594;
- 734;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 22 pages, 11 figures, 3 tables. Accepted for publication in ApJ