An ALMA survey of the SCUBA-2 CLS UDS field: Physical properties of 707 Sub-millimetre Galaxies

Dudzevičiūtė, U; Smail, Ian; Swinbank, AM; Stach, SM; Almaini, O; da Cunha, E; An, Fang Xia; Arumugam, V; Birkin, J; Blain, AW; Chapman, SC; Chen, C-C; Conselice, CJ; Coppin, KEK; Dunlop, JS; Farrah, D; Geach, JE; Gullberg, B; Hartley, WG; Hodge, JA; Ivison, RJ; Maltby, DT; Scott, D; Simpson, CJ; Simpson, JM; Thomson, AP; Walter, F; Wardlow, JL; Weiss, A; van der Werf, P

Abstract

We analyse the physical properties of a large, homogeneously selected sample of ALMA-located sub-millimetre galaxies (SMGs). This survey, AS2UDS, identified 707 SMGs across the ∼ 1 deg2 field, including ∼ 17 per cent which are undetected at K ≳ 25.7 mag. We interpret their UV-to-radio data using MAGPHYS and determine a median redshift of z = 2.61±0.08 (1-σ range of z = 1.8–3.4) with just ∼ 6 per cent at z > 4. Our survey provides a sample of massive dusty galaxies at z ≳ 1, with median dust and stellar masses of Md = (6.8±0.3) × 108 M⊙ (thus, gas masses of ∼ 1011 M⊙) and M* = (1.26±0.05) × 1011 M⊙. We find no evolution in dust temperature at a constant far-infrared luminosity across z ∼ 1.5–4. The gas mass function of our sample increases to z ∼ 2–3 and then declines at z > 3. The space density and masses of SMGs suggest that almost all galaxies with M* ≳ 3 × 1011 M⊙ have passed through an SMG-like phase. The redshift distribution is well fit by a model combining evolution of the gas fraction in halos with the growth of halo mass past a critical threshold of Mh ∼ 6 × 1012 M⊙, thus SMGs may represent the highly efficient collapse of gas-rich massive halos. We show that SMGs are broadly consistent with simple homologous systems in the far-infrared, consistent with a centrally illuminated starburst. Our study provides strong support for an evolutionary link between the active, gas-rich SMG population at z > 1 and the formation of massive, bulge-dominated galaxies across the history of the Universe.

Citation

Dudzevičiūtė, U., Smail, I., Swinbank, A., Stach, S., Almaini, O., da Cunha, E., …van der Werf, P. (2020). An ALMA survey of the SCUBA-2 CLS UDS field: Physical properties of 707 Sub-millimetre Galaxies. Monthly Notices of the Royal Astronomical Society, 494(3), 3828-3860. https://doi.org/10.1093/mnras/staa769

• Journal Article Type: Article
• Acceptance Date: Mar 11, 2020
• Online Publication Date: Apr 2, 2020
• Publication Date: May 31, 2020
• Deposit Date: Apr 3, 2020
• Publicly Available Date: Apr 3, 2020
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 494
• Issue: 3
• Pages: 3828-3860
• DOI: https://doi.org/10.1093/mnras/staa769