September 30
Dusty and Over-Pressured: Connecting Stellar Feedback from Normal Galaxies to Extreme Starbursts
Speaker: Deb Pathak, OSU
Abstract: The balance between stellar feedback (including radiation, warm gas, stellar winds), local ISM conditions, and self-gravity of star-forming regions sets the rate at which nebular regions grow and molecular clouds are disrupted. Using multi-wavelength data (JWST, HST, MUSE, ALMA, VLA, and MeerKAT) from the PHANGS (Physics at High Angular resolution in Nearby GalaxieS) survey, I will present the first inventory of 10 pc-scale pre-supernova stellar feedback pressures, self-gravity, and the dynamical state of ~18,000 star-forming regions in 19 nearby star-forming spiral galaxies. This includes the first measurement of infrared-reprocessed radiation pressures in a statistically large sample of star-forming regions. In PHANGS galaxies, we find warm gas pressure is able to drive HII region expansion, except in high-density galaxy centers. I will then show new results from the GOALS (Great Observatories All-sky LIRG/ULIRG Survey) collaboration, extending our 10 pc-scale feedback measurements to ~1,600 young clusters in the dusty, highly turbulent ISM of the nearest extreme starburst Luminous Infrared Galaxy (LIRG), NGC 3256. Using high-resolution JWST, MUSE, ALMA, and HST data, we measure feedback and ISM pressures that are ~2 orders of magnitude higher than in normal star-forming disks, where radiation (from both UV and infrared photons) instead of warm gas pressure drives region expansion. The infrared-reprocessed radiation pressure also rises from 5-10% of the UV radiation pressure in normal disks, to 30-50% in NGC 3256. Our pressure-balance accounting across PHANGS and NGC 3256 indicates that similar-sized nebular regions are on average similarly over-pressured relative to their confining environment, with local variations with ISM density. Finally, I will highlight future directions bridging stellar feedback in spirals with larger samples of LIRGs and more distant ULIRGs.
Host: Serena Cronin