Feedback in Emerging Extragalactic Star Clusters (JWST--FEAST): Calibration of Star Formation Rates in the Mid-Infrared with NGC 628

• DOI: 10.48550/arxiv.2406.01831
• Publication Date: 2024-06-03
• Authors: Daniela Calzetti; Angela Adamo; Sean T. Linden; Benjamin Gregg; Mark R. Krumholz; Varun Bajaj; A. Bik; M. Cignoni; Matteo Correnti; Bruce G. Elmegreen; Helena Faustino V...; J. S. Gallagher; Kathryn Grasha; R. A. Gutermuth; Kelsey E. Johnson; Matteo Messa; Jens Melinder; Göran Östlin; Alex Pedrini; Elena Sabbi; L. J. Smith; M. Tosi
• Keywords: Star (game theory)

New JWST near-infrared imaging of the nearby galaxy NGC 628 from Cycle 1 program JWST-FEAST is combined with archival mid-infrared to calibrate 21 $\mu$m emission as a star formation rate indicator (SFR) at $\sim$120 pc scales. The Pa$\alpha$ ($\lambda$1.8756 $\mu$m) hydrogen recombination line targeted by FEAST provides reference SFR that relatively insensitive dust attenuation, demonstrated combining this tracer HST H$\alpha$ imaging. Our analysis restricted regions appear compact in nebular and are sufficiently bright mitigate effects both age stochastic sampling stellar initial mass function. We find closely correlates emission, power-law exponent=1.07$\pm$0.01, agreement past results. hybrid using combination 24 (extrapolated tracers derive proportionality constant between two $b=0.095\pm0.007$, which $\sim$ 3-5 times larger than previous derivations large regions/entire galaxies. model these discrepancies an increasing contribution heating progressively older populations for spatial scales, earlier findings hierarchically distributed Thus, use indicators requires prior knowledge mean dominating heating, makes their application uncertain. Conversely, non-linear calibrations SFRs L(24) alone more robust, factor $\lesssim$2.5 variation across entire range luminosities HII