Herschel-ATLAS: properties of dusty massive galaxies at low and high redshifts
Abstract
We present a comparison of the physical properties of a rest-frame 250-μm-selected sample of massive, dusty galaxies from 0 < z < 5.3. Our sample comprises 29 high-redshift submillimetre galaxies (SMGs) from the literature and 843 dusty galaxies at z < 0.5 from the Herschel-Astrophysical TeraHertz Large Area Survey (H-ATLAS), selected to have a similar stellar mass to the SMGs. The z > 1 SMGs have an average star formation rate (SFR) of 390^{+80}_{-70} M⊙ yr-1, which is 120 times that of the low-redshift sample matched in stellar mass to the SMGs (SFR = 3.3 ± 0.2 M⊙ yr-1). The SMGs harbour a substantial mass of dust (1.2^{+0.3}_{-0.2}× {10}^9 M⊙), compared to (1.6 ± 0.1) × 108 M⊙ for low-redshift dusty galaxies. At low redshifts, the dust luminosity is dominated by the diffuse interstellar medium, whereas a large fraction of the dust luminosity in SMGs originates from star-forming regions. At the same dust mass, SMGs are offset towards a higher SFR compared to the low-redshift H-ATLAS galaxies. This is not only due to the higher gas fraction in SMGs but also because they are undergoing a more efficient mode of star formation, which is consistent with their bursty star formation histories. The offset in SFR between SMGs and low-redshift galaxies is similar to that found in CO studies, suggesting that dust mass is as good a tracer of molecular gas as CO.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2014
- DOI:
- 10.1093/mnras/stu510
- arXiv:
- arXiv:1403.2994
- Bibcode:
- 2014MNRAS.441.1017R
- Keywords:
-
- dust;
- extinction;
- galaxies: evolution;
- galaxies: fundamental parameters;
- galaxies: high-redshift;
- galaxies: ISM;
- submillimetre: galaxies;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 17 pages, 8 pages in Appendix, 12 figures, 2 tables. Accepted for publication in MNRAS. Minor typos corrected to match published version