Evolution of cosmic star formation in the SCUBA-2 Cosmology Legacy Survey
Artikel i vetenskaplig tidskrift, 2017

We present a new exploration of the cosmic star formation history and dust obscuration in massive galaxies at redshifts 0.5 < z < 6. We utilize the deepest 450-and 850-mu m imaging from SCUBA-2 CLS, covering 230 arcmin(2) in the AEGIS, COSMOS and UDS fields, together with 100-250 mu m imaging from Herschel. We demonstrate the capability of the T-PHOT deconfusion code to reach below the confusion limit, using multiwavelength prior catalogues from CANDELS/3D-HST. By combining IR and UV data, we measure the relationship between total star formation rate (SFR) and stellar mass up to z similar to 5, indicating that UV-derived dust corrections underestimate the SFR in massive galaxies. We investigate the relationship between obscuration and the UV slope (the IRX-beta relation) in our sample, which is similar to that of low-redshift starburst galaxies, although it deviates at high stellar masses. Our data provide new measurements of the total SFR density (SFRD) in M-* > 10(10) M-O galaxies at 0.5 < z < 6. This is dominated by obscured star formation by a factor of > 10. One third of this is accounted for by 450 mu m-detected sources, while one-fifth is attributed to UV-luminous sources (brighter than L-UV(*)), although even these are largely obscured. By extrapolating our results to include all stellar masses, we estimate a total SFRD that is in good agreement with previous results from IR and UV data at z <= 3, and from UV-only data at z similar to 5. The cosmic star formation history undergoes a transition at z similar to 3-4, as predominantly unobscured growth in the early Universe is overtaken by obscured star formation, driven by the build-up of the most massive galaxies during the peak of cosmic assembly.

submillimetre: diffuse background

galaxies: high-redshift

methods: statistical



N. Bourne

University of Edinburgh

J.S. Dunlop

University of Edinburgh

E. Merlin

Osservatorio Astronomico di Roma

S. Parsa

University of Edinburgh

C. Schreiber

Universiteit Leiden

M. Castellano

Osservatorio Astronomico di Roma

C. Conselice

University of Nottingham

K. E. K. Coppin

University of Hertfordshire

D. Farrah

Virginia Polytechnic Institute and State University

A. Fontana

Osservatorio Astronomico di Roma

J.E. Geach

University of Hertfordshire

M. Halpern

University of British Columbia (UBC)

Kirsten Kraiberg Knudsen

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

M. J. Michalowski

University of Edinburgh

A. Mortlock

University of Edinburgh

P. Santini

Osservatorio Astronomico di Roma

D. Scott

University of British Columbia (UBC)

X. W. Shu

Anhui Normal University

C. Simpson

Gemini Observatory North

J. M. Simpson

University of Edinburgh

D. J. B. Smith

University of Hertfordshire

P.P. van der Werf

Universiteit Leiden

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 467 1360-1385


Astronomi, astrofysik och kosmologi


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