12:00–1:00 pm ERC 401
Arianna Long (UC Irvine) "Missing Giants: The First Massive Galaxies Are Dust-Obscured"
Half of all cosmic starlight is absorbed and reprocessed by dust, which means that the widely-accepted cosmic history generated by visible-light telescopes is incomplete. The consequences of our biases are apparent in our most modern cosmological simulations: they struggle to produce sufficient populations of massive galaxies to match observations of the first 2 Gyr of the Universe. These giants likely underwent rapid, violent, and bursty phases of star formation in order to reach such extreme masses, so early on. Such rapid stellar growth produces an overabundance of dust that obscures starlight, rendering the galaxies near-invisible at UV/optical wavelengths. In this work, I compile empirical data on massive, dusty, star-forming galaxies to create a numerical model that re-derives the primary function describing stellar mass assembly in the Universe: the stellar mass function (SMF). With my model, I extend the massive end of the SMF and show that, to first order, we can successfully reproduce the rapid build up of the massive quiescent galaxy population at z > 1 — aka the predicted descendants of dusty, star-forming galaxies. I detail the impact of this model on our understanding of massive galaxy formation and cosmic stellar mass assembly, and I briefly review how current and next-generation telescopes will play a key role in this endeavor.
