Submillimetre flux as a probe of molecular ISM mass in high-z galaxies. (27th April 2018)

• Record Type: Journal Article
• Authors: Liang, Lichen; Feldmann, Robert; Faucher-Giguère, Claude-André; Kereš, Dušan; Hopkins, Philip F; Hayward, Christopher C; Quataert, Eliot; Scoville, Nick Z
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 478:Number 1(2018:Jul.)
• Page Start: L83
• Page End: L88
• Publication Date: 2018-04-27
• Subjects: galaxies: evolution -- galaxies: high-redshift -- galaxies: ISM -- submillimetre: galaxies; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/sly071
• Languages: English
• ISSNs: 1745-3933

Abstract

Abstract: Recent long-wavelength observations on the thermal dust continuum suggest that the Rayleigh–Jeans tail can be used as a time-efficient quantitative probe of the dust and interstellar medium (ISM) mass in high- z galaxies. We use high-resolution cosmological simulations from the Feedback in Realistic Environment (FIRE) project to analyse the dust emission of M * ≳ 10 10 M⊙ galaxies at z = 2–4. Our simulations (MassiveFIRE ) explicitly include various forms of stellar feedback, and they produce the stellar masses and star formation rates of high- z galaxies in agreement with observations. Using radiative transfer modelling, we show that sub-millimetre (sub-mm) luminosity and molecular ISM mass are tightly correlated and that the overall normalization is in quantitative agreement with observations. Notably, sub-mm luminosity traces molecular ISM mass even during starburst episodes as dust mass and mass-weighted temperature evolve only moderately between z = 4 and z = 2, including during starbursts. Our finding supports the empirical approach of using broadband sub-mm flux as a proxy for molecular gas content in high- z galaxies. We thus expect single-band sub-mm observations with ALMA to dramatically increase the sample size of high- z galaxies with reliable ISM masses in the near future.