HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Physical Characterization of an Unlensed, Dusty Star-forming Galaxy at z = 5.85

Abstract : We present a physical characterization of MM J100026.36+021527.9 (a.k.a. “MAMBO-9”), a dusty star-forming galaxy (DSFG) at z = 5.850 ± 0.001. This is the highest-redshift unlensed DSFG (and fourth most distant overall) found to date and is the first source identified in a new 2 mm blank-field map in the COSMOS field. Though identified in prior samples of DSFGs at 850 μm to 1.2 mm with unknown redshift, the detection at 2 mm prompted further follow-up as it indicated a much higher probability that the source was likely to sit at z > 4. Deep observations from the Atacama Large Millimeter and submillimeter Array (ALMA) presented here confirm the redshift through the secure detection of 12CO(J = 6→5) and p-H2O (21,1 → 20,2). MAMBO-9 is composed of a pair of galaxies separated by 6 kpc with corresponding star formation rates of 590 M yr-1 and 220 M yr-1, total molecular hydrogen gas mass of (1.7 ± 0.4) × 1011 M , dust mass of (1.3 ± 0.3) × 109 M , and stellar mass of ({3.2}-1.5+1.0) × 109 M . The total halo mass, (3.3 ± 0.8) × 1012 M , is predicted to exceed 1015 M by z = 0. The system is undergoing a merger-driven starburst that will increase the stellar mass of the system tenfold in τ depl = 40-80 Myr, converting its large molecular gas reservoir (gas fraction of {96}-2+1 % ) into stars. MAMBO-9 evaded firm spectroscopic identification for a decade, following a pattern that has emerged for some of the highest-redshift DSFGs found. And yet, the systematic identification of unlensed DSFGs like MAMBO-9 is key to measuring the global contribution of obscured star formation to the star formation rate density at z ≳ 4, the formation of the first massive galaxies, and the formation of interstellar dust at early times (≲1 Gyr).
Document type :
Journal articles
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03666701
Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Thursday, May 12, 2022 - 4:44:49 PM
Last modification on : Saturday, May 14, 2022 - 3:03:48 AM

Links full text

Identifiers

Collections

Citation

Caitlin M. Casey, Jorge A. Zavala, Manuel Aravena, Matthieu Béthermin, Karina I. Caputi, et al.. Physical Characterization of an Unlensed, Dusty Star-forming Galaxy at z = 5.85. The Astrophysical Journal, 2019, 887, ⟨10.3847/1538-4357/ab52ff⟩. ⟨insu-03666701⟩

Share

Metrics

Record views

0