2020A&A...640L...8U -
Astronomy and Astrophysics, volume 640, L8-8 (2020/8-1)
ALMA Deep Field in SSA22. A near-infrared-dark submillimeter galaxy at z = 4.0.
UMEHATA H., SMAIL I., SWINBANK A.M., KOHNO K., TAMURA Y., WANG T., AO Y., HATSUKADE B., KUBO M., NAKANISHI K. and HAYATSU N.N.
Abstract (from CDS):
Deep surveys with the Atacama Large Millimeter Array (ALMA) have uncovered a population of dusty star-forming galaxies which are faint or even undetected at optical to near-infrared wavelengths. Their faintness at short wavelengths makes the detailed characterization of the population challenging. Here we present a spectroscopic redshift identification and a characterization of one of these near-infrared-dark galaxies discovered by an ALMA deep survey. The detection of [CI](1-0) and CO(4-3) emission lines determines the precise redshift of the galaxy, ADF22.A2, to be z=3.9913±0.0008. On the basis of a multi-wavelength analysis, ADF22.A2 is found to be a massive, star-forming galaxy with a stellar mass of M*=1.1–0.6+1.3x1011M☉ and SFR=430–150+230M☉/yr. The molecular gas mass was derived to be M(H2)[CI]=(5.9±1.5)x1010M☉, indicating a gas fraction of ≃35%, and the ratios of L[CI](1–0)/LIR and L[CI](1–0)/LCO(4–3) suggest that the nature of the interstellar medium in ADF22.A2 is in accordance with those of other bright submillimeter galaxies. The properties of ADF22.A2, including the redshift, star-formation rate, stellar mass, and depletion time scale (τdep≃0.1-0.2Gyr), also suggest that ADF22.A2 has the characteristics expected for the progenitors of quiescent galaxies at z≥3. Our results demonstrate the power of ALMA contiguous mapping and line scan, which help us to obtain an unbiased view of galaxy formation in the early Universe.
Abstract Copyright:
© ESO 2020
Journal keyword(s):
submillimeter: galaxies - galaxies: starburst - galaxies: high-redshift - submillimeter: ISM - galaxies: evolution
Simbad objects:
7
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2020A&A...640L...8U and select 'bookmark this link' or equivalent in the popup menu