All Categories

At z = 1 - 3 (approximately 7 - 11 Gyr ago), the formation of new stars in the Universe occurs mainly in massive, dusty galaxies. In the past decade, the Herschel Space Observatory showed the surprising result that these distant galaxies are much colder than their counterparts in the local Universe. I explore the reasons for the evolving infrared emission of similar galaxies over cosmic time. Despite similar rates of star formation, dusty galaxies existing 10 Gyr ago have an order of magnitude higher dust masses and higher gas masses than local galaxies. Even with the increase in gas, which is fuel for star formation, these distant galaxies are predominantly inefficient at converting gas to stars. I also discuss the effect of a luminous central black hole on the observed infrared emission. I demonstrate that an active galactic nucleus is linked with declining star formation in massive galaxies.  I estimate that dust-enshrouded black holes are lurking in most galaxies, and I devise new diagnostics to hunt for these hidden phenomena in the distant Universe with the upcoming James Webb Space Telescope.