First accurate constraint of cold dust and gas properties in the EoR
NOEMA | 20.0hrs | PI - D. Liu
How galaxies grow their metals and stellar masses in the first few hundred million years is a fundamental question. The evolution of cold gas depletion time, gas fraction and dust temperature is well established out to redshift z~5, however, little is known in the epoch of reionization (EoR). The insufficient number of spectroscopically identified EoR galaxies and their extreme faintness in dust continuum are the main reasons hampering an accurate determination of their dust and cold gas properties. Here we select the newly-confirmed, 1.3mm-brightest and most-massive/dusty EoR target (with robust [CII] spec-z=7.31) among the 40+ known spec-z>6.5 galaxies in the EoR to detect its Rayleigh-Jeans (RJ) tail rest-frame 250um flux at 2mm using 20 hours of NOEMA time. This is the first RJ dust study in the EoR, and will make the target the first golden reference for: a) accurate (cold) dust and gas properties; b) CII vs. RJ dust continuum cold gas mass calibration for high-z CII studies; c) cold gas depletion time, gas fraction and dust temperature evolution towards z~7.3.