The Evolution of the IR Luminosity Function and Dust-obscured Star Formation over the Past 13 Billion Years
Journal article, 2021
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 arcmin(2)) and the only at 2 mm to search for dusty star-forming galaxies (DSFGs). We use the 13 sources detected above 5 sigma 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 alpha(LF) = -0.42(-0.04)(+0.02). We conclude that the dust-obscured component, which peaks at z approximate to 2-2.5, has dominated the cosmic history of star formation for the past similar to 12 billion years, back to z similar to 4. At z = 5, the dust-obscured star formation is estimated to be similar to 35% of the total star formation rate density and decreases to 25%-20% at z = 6-7, implying a minor contribution of dusten-shrouded 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.
Luminosity function
Galaxy evolution
Star formation
Dust continuum emission
High-redshift galaxies
Submillimeter astronomy
Surveys
Millimeter astronomy
Galaxy counts
Galaxies
Author
J. A. Zavala
University of Texas
C. M. Casey
University of Texas
S. M. Manning
University of Texas
M. Aravena
Diego Portales University
M. Bethermin
Aix Marseille University
K. I. Caputi
University of Copenhagen
University of Groningen
D. L. Clements
Imperial College London
E. da Cunha
University of Western Australia
P. Drew
University of Texas
S. L. Finkelstein
University of Texas
S. Fujimoto
University of Copenhagen
C. Hayward
Flatiron Institute
J. Hodge
Leiden University
J. S. Kartaltepe
Rochester Institute of Technology
Kirsten Kraiberg Knudsen
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
A. M. Koekemoer
Space Telescope Science Institute (STScI)
A. S. Long
University of California
G. E. Magdis
Technical University of Denmark (DTU)
National Observatory of Athens
University of Copenhagen
A. W. S. Man
University of Toronto
G. Popping
European Southern Observatory Santiago
D. Sanders
University of Hawaii
N. Scoville
California Institute of Technology (Caltech)
K. Sheth
National Aeronautics and Space Administration (NASA)
J. Staguhn
Johns Hopkins University
National Aeronautics and Space Administration (NASA)
S. Toft
University of Copenhagen
E. Treister
Pontificia Universidad Catolica de Chile
J. D. Vieira
University of Illinois
M. S. Yun
University of Massachusetts
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 909 2 165Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Probability Theory and Statistics
Geosciences, Multidisciplinary
DOI
10.3847/1538-4357/abdb27