Affiliation: UT Austin

Contribution: Invited

Title: Gas and Dust at Early Epochs

Abstract: Recent JWST observations have revealed an unexpected abundance of bright galaxies at z>9 though the origins of this population remain unclear. To address this, a comprehensive study of star formation, dust, and gas in early systems is essential. Past star formation is imprinted in dust, while gas regulates future star formation. In this talk, I will review the latest developments in these areas and discuss a coherent view on the origin of these early bright galaxies. I will begin with recent intensive ALMA surveys, both in general fields and in lensing cluster fields. These results indicate that the faint-end slope of 1-mm number counts is not flattening, supporting evidence for an additional (~60%) component of the star formation rate density (SFRD) at z=4-8 , contributed by faint, dusty populations. This remarks the importance of quantifying dust in the early universe, and I will also review recent detailed measurements of dust mass in galaxies at z>6, suggesting the need for efficient dust growth in the ISM. Additionally, I will discuss detailed ISM characterizations of a strongly lensed galaxy at z=6 where unprecedented sensitivity and spatial resolution reveal numerous stellar clumps embedded in a smooth, rotating disk. This finding points to weak feedback and high gas density, in line with efficient dust production and growth in early galaxies. Finally, I will introduce an ongoing ALMA+JWST IFU survey, which promises to provide new insights into dust, gas, and feedback mechanisms in these early systems.

This contribution can be found here (pdf).