FIR-luminous [C ii] Emitters in the ALMA-SCUBA-2 COSMOS Survey (AS2COSMOS): The Nature of Submillimeter Galaxies in a 10 Comoving Megaparsec-scale Structure at z similar to 4.6

0553712 - ASÚ 2022 RIV GB eng J - Článek v odborném periodiku
Mitsuhashi, I. … celkem 23 autorů
FIR-luminous [C ii] Emitters in the ALMA-SCUBA-2 COSMOS Survey (AS2COSMOS): The Nature of Submillimeter Galaxies in a 10 Comoving Megaparsec-scale Structure at z similar to 4.6.
Astrophysical Journal. Roč. 907, č. 2 (2021), č. článku 122. ISSN 0004-637X. E-ISSN 1538-4357
Výzkumná infrastruktura: EU-ARC.CZ II - 90106
Klíčová slova: galaxy formation * galaxy evolution * galaxy environments
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 5.521, rok: 2021
Způsob publikování: Omezený přístup
https://doi.org/10.3847/1538-4357/abcc72

We report the discovery of a 10 comoving megaparsec (cMpc)-scale structure traced by massive submillimeter galaxies (SMGs) at z similar to 4.6. These galaxies are selected from an emission line search of ALMA Band 7 observations targeting 184 luminous submillimeter sources (S-850 mu m >= 6.2 mJy) across 1.6 degrees(2) in the COSMOS field. We identify four [C ii] emitting SMGs and two probable [C ii] emitting SMG candidates at z = 4.60-4.64 with velocity-integrated signal-to-noise ratio of S/N > 8. Four of the six emitters are near-infrared blank SMGs. After excluding one SMG whose emission line is falling at the edge of the spectral window, all galaxies show clear velocity gradients along the major axes that are consistent with rotating gas disks. The estimated rotation velocities of the disks are 330-550 km s(-1) and the inferred host dark-matter halo masses are similar to 2-8 x 10(12) M. From their estimated halo masses and [C ii] luminosity function, we suggest that these galaxies have a high (50%-100%) duty cycle and high (similar to 0.1) baryon conversion efficiency (SFR relative to baryon accretion rate), and that they contribute 2% to the total star formation rate density at z = 4.6. These SMGs are concentrated within just 0.3% of the full survey volume, suggesting they are strongly clustered. The extent of this structure and the individual halo masses suggest that these SMGs will likely evolve into members of a similar to 10(15) M cluster at z = 0. This survey reveals a synchronized dusty starburst in massive halos at z > 4, which could be driven by mergers or fed by smooth gas accretion.
Trvalý link: http://hdl.handle.net/11104/0328464