Abstract
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.
Funder
National Science Foundation of China
Major Science and Technology Project of Qinghai Province
China Manned Space Project
China-Chile Joint Research Fund
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics