The Evolution of the IR Luminosity Function and Dust-obscured Star Formation over the Past 13 Billion Years

• Published in: The Astrophysical journal Vol. 909; no. 2; pp. 165 - 179
• Main Authors: Zavala, J. A., Casey, C. M., Manning, S. M., Aravena, M., Bethermin, M., Caputi, K. I., Clements, D. L., Cunha, E. da, Drew, P., Finkelstein, S. L., Fujimoto, S., Hayward, C., Hodge, J., Kartaltepe, J. S., Knudsen, K., Koekemoer, A. M., Long, A. S., Magdis, G. E., Man, A. W. S., Popping, G., Sanders, D., Scoville, N., Sheth, K., Staguhn, J., Toft, S., Treister, E., Vieira, J. D., Yun, M. S.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01.03.2021; IOP Publishing; American Astronomical Society
• Subjects: Astronomical models; Astrophysics; Constraint modelling; Cosmic dust; Dust; Dust continuum emission; Evolution; Galactic evolution; Galaxies; Galaxy counts; Galaxy evolution; High-redshift galaxies; Ionization; Luminosity; Luminosity function; Millimeter astronomy; Occultation; Polls & surveys; Radio telescopes; Red shift; Sciences of the Universe; Space density; Star & galaxy formation; Star formation; Star formation rate; Stars; Stars & galaxies; Stellar evolution; Submillimeter astronomy; Surveys; Universe; Surveys; Galaxy evolution; Astrophysics - Astrophysics of Galaxies; Star formation; Submillimeter astronomy; Galaxies; High-redshift galaxies; Galaxy counts; Millimeter astronomy; Luminosity function; Dust continuum emission
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/1538-4357/abdb27

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 σ 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 . 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.