The evolution of the IR luminosity function and dust-obscured star formation over the past 13 billion years
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
We present the first results from the Mapping Obscuration to Reionization with ALMA (MORA) survey, the largest Atacama Large Millimeter/submillimeter Array (ALMA) blank-field contiguous survey to date (184 arcmin2) and the only at 2 mm to search for dusty star-forming galaxies (DSFGs). We use the 13 sources detected above 5σ to estimate the first ALMA galaxy number counts at this wavelength. These number counts are then combined with the state-of-the-art galaxy number counts at 1.2 and 3 mm and with a backward evolution model to place constraints on the evolution of the IR luminosity function and dust-obscured star formation in the past 13 billion years. Our results suggest a steep redshift evolution on the space density of DSFGs and confirm the flattening of the IR luminosity function at faint luminosities, with a slope of αLF = -0.42+0.02-0.04. We conclude that the dust-obscured component, which peaks at z ≈ 2–2.5, has dominated the cosmic history of star formation for the past ∼12 billion years, back to z ∼ 4. At z = 5, the dust-obscured star formation is estimated to be ∼35% of the total star formation rate density and decreases to 25%–20% at z = 6–7, implying a minor contribution of dust-enshrouded star formation in the first billion years of the universe. With the dust-obscured star formation history constrained up to the end of the epoch of reionization, our results provide a benchmark to test galaxy formation models, to study the galaxy mass assembly history, and to understand the dust and metal enrichment of the universe at early times.
Date Issued
2021-03-10
Date Acceptance
2021-01-11
Citation
The Astrophysical Journal (ApJ), 2021, 909 (2)
ISSN
0004-637X
Publisher
IOP Publishing
Journal / Book Title
The Astrophysical Journal (ApJ)
Volume
909
Issue
2
Copyright Statement
Copyright © 2021IOP Publishing Ltd. This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal, Volume 909, Number 2. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at 10.3847/1538-4357/abdb27
Subjects
ALMA SURVEY
Astronomy & Astrophysics
COSMOLOGY LEGACY SURVEY
DEEP FIELD SOUTH
Dust continuum emission
FORMATION RATE DENSITY
Galaxies
Galaxy counts
Galaxy evolution
GALAXY FORMATION
High-redshift galaxies
Luminosity function
Millimeter astronomy
MU-M
Physical Sciences
PHYSICAL-PROPERTIES
REDSHIFT DISTRIBUTION
Science & Technology
Star formation
Submillimeter astronomy
SUBMILLIMETER NUMBER COUNTS
Surveys
UNIVERSE
Publication Status
Published
Article Number
165
Date Publish Online
2021-03-15