AR 16636 (Archival Research)

Sun Jul 14 05:49:41 GMT 2024

Principal Investigator: David Thilker
PI Institution: The Johns Hopkins University
Investigators (xml)

Title: How do local environmental conditions influence the stellar cluster mass-radius relation?
Cycle: 29

HST's resolution opened the study of stellar cluster morphology to observed populations in galaxies throughout the Local Volume and beyond. The structure of stellar clusters is expected to be intimately linked to the physical conditions of their birthplace and to their subsequent path through a host galaxy. Models have had success predicting the cluster mass-radius relation (MRR). However, getting the details right requires dedicated new work from the observational side because extragalactic samples of relevant measurements remain scant and open to improvement in mass/age estimation. There now exists droves of panchromatic HST imaging with WFC3/UVIS for representative samples of typical star-forming nearby galaxies, with the two principal efforts at relevant distances being LEGUS and PHANGS-HST. Even so, a comprehensive investigation into cluster morphology remains unrealized. We now propose such an Archival HST study, aiming to revolutionize the understanding of environmentally-driven MRR dependencies and propel the next generation of simulations with new, fine-grained constraint. Capitalizing on two Legacy surveys, we will analyze ~60,000-70,000 clusters, probing all environments with dramatically increased statistical rigor, allowing for aggregation of samples binned on such local properties (which we have already opitmally determined). We will create and publish/release a cluster catalog with improved structural fits and (age, mass) for use by the community, and answer the most pressing open questions emerging from theoretical modeling of cluster formation and evolution.