FLASH Talks: Sean Linden (Steward) & Jimena Rodriquez (Steward)
Friday, 01 December 2023 noon — 1 p.m. MST
NOIRLab Headquarters | 950 North Cherry Ave., Tucson, AZ 85719
Sean Linden, Steward
Lifting Back the Veil: The Search for Dusty Star Clusters in Nearby Galaxies
Young massive star clusters (YMCs) represent a fundamental unit of star formation and stellar feedback in galaxies. However, questions remain regarding the timescales and conditions necessary for YMCs to form and evolve in the densest and dustiest regions of the interstellar medium (ISM). Thanks to JWST’s unprecedented capabilities, I will present ongoing work to identify and characterize dust-embedded YMCs in both normal and starburst galaxies in the local Universe. By combining observations from 0.3-4.4um we have fit the spectral energy distributions (SED) of all 2207 YMC candidates in NGC 628 to derive physical quantities (age, mass, extinction, and dust properties), finding evidence for a change in the dust grain size distribution as YMCs emerge from there birth clouds. Further, with multi-band NIRCam observations in combination with the NIRSpec IFU we find correlations in the near-infrared colors of YMCs with both the Pa-alpha and 3.3um PAH line strength, suggesting a rapid evolutionary sequence as clusters clear their surroundings in the nucleus of NGC 3256. The wide range of ISM physical conditions seen amongst nearby galaxies affords us a high-resolution look at how star formation activity evolves with environment.
Jimena Rodriquez, Steward
Ready or not here I come! Using 3.3um PAH emission to hunt for dust-embedded star formation
The earliest stages of star formation occur inside dense cocoons of gas and dust that conceal their presence at optical wavelengths. Thanks to the unprecedented IR capabilities of JWST we are able to observe for the first time dust obscured star formation sites with ~10 pc resolution beyond the Magellanic Clouds. Early results from PHANGS-JWST suggested that 3.3μm PAH emission is an excellent indicator of star clusters still in this dusty phase. In this talk I will present my ongoing work on the detection and properties of the 3.3 um PAH emitters throughout the 19 galaxies of the PHANGS-JWST Cycle 1 Treasury Survey. The comparison with clusters catalogs from HST suggests that the timescale for 3.3 um PAH emission at the cluster scale, and the embedded phase of star formation must be very short, lasting less than 2 Myr.