Dust and gas in star forming galaxies at z~3 - extending galaxy uniformity to 11.5 billion years

Magdis, G E, Rigopoulou, D, Daddi, E, Bethermin, M, Feruglio, C, Sargent, M, Dannerbauer, H, Dickinson, M, Elbaz, D, Gomez Guijarro, C, Huang, J-S, Toft, S and Valentino, F (2017) Dust and gas in star forming galaxies at z~3 - extending galaxy uniformity to 11.5 billion years. Astronomy and Astrophysics, 603. ISSN 0004-6361

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We present millimetre dust emission measurements of two Lyman Break Galaxies at z~3 and construct for the first time fully sampled infrared spectral energy distributions (SEDs), from mid-IR to the Rayleigh-Jeans tail, of individually detected, unlensed, UV-selected, main sequence (MS) galaxies at z=3. The SED modelling of the two sources confirms previous findings, based on stacked ensembles, of an increasing mean radiation field <U> with redshift, consistent with a rapidly decreasing gas metallicity in z > 2 galaxies. Complementing our study with CO[3-2] emission line observations, we measure the molecular gas mass (M_H2) reservoir of the systems using three independent approaches: 1) CO line observations, 2) the dust to gas mass ratio vs metallicity relation and 3) a single band, dust emission flux on the Rayleigh-Jeans side of the SED. All techniques return consistent M_H2 estimates within a factor of ~2 or less, yielding gas depletion time-scales (tau_dep ~ 0.35 Gyrs) and gas-to-stellar mass ratios (M_H2/M* ~ 0.5-1) for our z~3 massive MS galaxies. The overall properties of our galaxies are consistent with trends and relations established at lower redshifts, extending the apparent uniformity of star-forming galaxies over the last 11.5 billion years.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups: Astronomy Centre
Subjects: Q Science > QB Astronomy
Depositing User: Mark Sargent
Date Deposited: 06 Jun 2017 07:48
Last Modified: 26 Jan 2018 12:04
URI: http://srodev.sussex.ac.uk/id/eprint/68347

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Project NameSussex Project NumberFunderFunder Ref
From gas to stars: 12 billion years of galaxy growthG1946-02Royal SocietyLT150041