Astronomy Tea Talk

Star-formation is regulated by the physical conditions of the interstellar medium (ISM), where gas cooling, heating, and feedback from stars and active galactic nuclei (AGN) all compete to drive the evolution of galaxies. In this talk, I discuss the nature of stellar and supermassive black hole assembly from cold gas using multi-wavelength observations of z=0-2 luminous, infrared (IR) galaxies and supporting simulations. With combined ALMA, VLA, and Spitzer data, I measure physical quantities of the ISM such as the gas heating efficiency which depends strongly on the composition of dust grains. Compact, IR-luminous galaxies at all redshifts exhibit low heating efficiencies and high star-formation efficiencies, linking parsec-scale ISM properties of star-forming regions to the global evolution of the galaxy. There is evidence for unusually low gas heating rates at z~2 which may contribute to the high star-formation rates at cosmic noon. I will discuss how ongoing research and upcoming ALMA programs will statistically test this hypothesis, and present results from supporting simulations on the cold dust properties of AGN host star-forming galaxies.