PhD Thesis Defense: Clarke Esmerian

11:00 am–12:00 pm ERC 401

Clarke Esmerian "Modeling Dust Production, Growth, and Destruction in Reionization-Era Galaxies"

We introduce a model for the explicit evolution of interstellar dust in a cosmological galaxy formation simulation. This model incorporates the effects of dust grain production in asymptotic giant branch star (AGB) winds and supernovae (SN), grain growth due to the accretion of heavy elements from the gas phase of the interstellar medium (ISM), and grain destruction due to thermal sputtering in the high temperature gas of supernova remnants (SNRs). Since these processes are deeply uncertain, we use a flexible post-processing method that allows us to vary the parameters of the dust model.

We then apply the model to a suite of simulated galaxies in the first 1.2 billion years of the universe (up to and including z = 5). We vary the dust model parameters to quantify their effect on the predicted dust content of high redshift galaxies and forward model observable properties to compare to existing data.  We find that we are unable to simultaneously match all existing observational constraints with any one set of model parameters. An analysis of the spatial distribution of dust in our models indicates that they also fail to reproduce the morphological complexity apparent in high resolution observations.

We thereby conclude that we still lack a model that fundamentally captures the nature of cosmic dust in high-redshift galaxies. Our results therefore provide strong motivation for the development of a similar dust model in higher-resolution simulations of galaxy formation which more realistically reproduce the dynamics of the reionization-era ISM.

Event Type

PhD Thesis Defenses

Jun 27