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.

High-redshift galaxies

Galaxy counts

Galaxy evolution

Star formation

Submillimeter astronomy

Surveys

Dust continuum emission

Galaxies

Millimeter astronomy

Luminosity function

Author

J. A. Zavala

The University of Texas at Austin

C. M. Casey

The University of Texas at Austin

S. M. Manning

The University of Texas at Austin

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

The University of Texas at Austin

S. L. Finkelstein

The University of Texas at Austin

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 at Irvine (UCI)

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

NASA Goddard Space Flight Center

Johns Hopkins University

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 2 165

Subject Categories

Astronomy, Astrophysics and Cosmology

Probability Theory and Statistics

Geosciences, Multidisciplinary

DOI

10.3847/1538-4357/abdb27

More information

Latest update

3/30/2021