AR 16145 (Archival Research)

Mon Jul 15 05:30:36 GMT 2024

Principal Investigator: Desika Narayanan
PI Institution: University of Florida
Investigators (xml)

Title: The Dust Extinction Law in Local Galaxies: Enhancing HST Data Products from Cosmological Galaxy Formation Simulations
Cycle: 28

The extinction of UV-NIR photons from starlight by cosmic dust represents a significant uncertainty in the derivation of galaxy physical properties. While HST has played a foundational role in deriving dust extinction laws in the Galaxy and nearby systems, these observations have demonstrated that there is significant dispersion in the reddening law both from sightline to sightline in the Milky Way, as well as from galaxy to galaxy in the Local Group. No universal dust extinction law exists. The fundamental goal of this Theory/AR proposal is to deploy new hydrodynamic galaxy formation simulations that model the formation, growth, and destruction of dust over cosmic time to provide the first cosmologically motivated model for dust extinction laws in galaxies. This on-the-fly model includes the detailed physics of dust formation in stellar ejecta, growth in the ISM, and destruction processes. Our goal with these models is to use the simulation data products to: [1] develop an understanding for the origin of and expected dispersion amongst extinction laws in Local Group-like galaxies; and [2] develop a modern parameterization of the dust extinction law in order to facilitate the interpretation of UV-NIR HST observations toward star clusters and galaxies.