Molecular Gas, Chemical Enrichment, and Feedback on the Molecular ISM of Dusty Galaxies in the Early Universe

Mon, December 07, 2015

Ral seminar image for website

Out to at least z~4, the abundance of galaxies with stellar masses above log(M*/Msun)~11 suffers an exponential drop. These galaxies host little ongoing star formation, and appear to have been quickly and efficiently "quenched," but the process(es) by which quenching occurs are poorly understood. Recent observations and circumstantial evidence suggest that the bulk of star formation in the earliest quiescent galaxies took place in highly dust-obscured star-forming galaxies. I will discuss recent efforts to detect and resolve the gas and dust on sub-kiloparsec scales using observations of gravitationally lensed dusty galaxies discovered by the South Pole Telescope conducted by ALMA and other facilities. These observations demonstrate the richness of the molecular ISM, shed light on the relative distribution of star formation and the gas from which stars form, and offer a unique window into the evolution of dust galaxies impossible without the aid of gravitational lensing. Finally, I will present new ALMA observations which show clear signs of feedback on the molecular ISM in dusty star-forming galaxies at z~6, providing tantalizing evidence of an evolutionary connection between high-redshift dusty galaxies and the first massive, quiescent systems.