Uncovering a unique population of gas giants at <z>=1.2

NOEMA | 8.0hrs | PI - V. Kokorev

We have discovered a new population of galaxies in the distant Universe (z>1) with extremely cold dust temperatures, similar to the coldest galaxies in the local Universe. Taken at face value, this corresponds to very large dust masses and, as a result, extreme gas fractions. The nature of these galaxies is puzzling, as such extreme gas enrichment are not predicted by either theoretical models or existing empirical observations. We propose to infer and confirm the gas mass (Mgas), and the dust mass (Mdust) for two “gas-giants” at =1.2, that lie on the main-sequence of star-formation. Our goal is to detect the CO(2-1) emission line, as well as the dust continuum at rest frame 1.2 mm, with a set of efficiently designed observations.These observations will target a robustly selected, representative sample of these objects, to act as a pilot study into these unique and unexpected systems. In particular with the proposed observations we will 1) explore and put constraints the dust/gas masses and fractions in these giants 2) confirm the extreme nature of these objects to facilitate a larger follow-up proposal to observe the full population.