JWST-FEAST: Feedback in Emerging extrAgalactic Star clusTers: Calibration of Star Formation Rates in the Mid-infrared with NGC 628
Abstract New JWST near-infrared imaging of the nearby galaxy NGC 628 from the JWST Cycle 1 program Feedback in Emerging extrAgalactic Star clusTers (JWST-FEAST) is combined with archival JWST mid-infrared imaging to calibrate the 21 μ m emission as a star formation rate (SFR) indicator at ∼120 pc scales. The Pa α (1.8756 μ m) hydrogen recombination emission line targeted by FEAST provides a reference SFR indicator that is relatively insensitive to dust attenuation, as demonstrated by combining this tracer with Hubble Space Telescope H α imaging. Our analysis is restricted to regions that appear compact in nebular line emission and are sufficiently bright to mitigate effects of both age and stochastic sampling of the stellar initial mass function. We find that the 21 μ m emission closely correlates with the nebular line emission, with a power law with exponent = 1.07 ± 0.01, in agreement with past results. We calibrate a hybrid SFR indicator using a combination of H α and 24 μ m (extrapolated from 21 μ m) tracers and derive the proportionality constant between the two tracers, b = 0.095 ± 0.007, which is ∼3–5 times larger than previous derivations using large regions/entire galaxies. We model these discrepancies as an increasing contribution to the dust heating by progressively older stellar populations for increasing spatial scale, in agreement with earlier findings that star formation is hierarchically distributed in galaxies. Thus, the use of hybrid SFR indicators requires prior knowledge of the mean age of the stellar populations dominating the dust heating, which makes their application uncertain. Conversely, nonlinear calibrations of SFRs from L (24) alone are more robust, with a factor ≲ 2.5 variation across the entire range of L (24) luminosities from H ii regions to galaxies.
Authors
- Daniela Calzetti (ORCID: https://orcid.org/0000-0002-5189-8004)
- Varun Bajaj (ORCID: https://orcid.org/0009-0008-4009-3391)
- Elena Sabbi (ORCID: https://orcid.org/0000-0003-2954-7643)
- Robert Gutermuth (ORCID: https://orcid.org/0000-0002-6447-899X)
- Mark R. Krumholz (ORCID: https://orcid.org/0000-0003-3893-854X)
- Matteo Correnti (ORCID: https://orcid.org/0000-0001-6464-3257)
- Kelsey E. Johnson (ORCID: https://orcid.org/0000-0001-8348-2671)
- Benjamin Gregg (ORCID: https://orcid.org/0000-0003-4910-8939)
- Matteo Messa (ORCID: https://orcid.org/0000-0003-1427-2456)
- Bruce G. Elmegreen (ORCID: https://orcid.org/0000-0002-1723-6330)
- Göran Östlin (ORCID: https://orcid.org/0000-0002-3005-1349)
- M. Cignoni (ORCID: https://orcid.org/0000-0001-6291-6813)
- Angela Adamo (ORCID: https://orcid.org/0000-0002-8192-8091)
- Kathryn Grasha (ORCID: https://orcid.org/0000-0002-3247-5321)
- Alex Pedrini (ORCID: https://orcid.org/0000-0002-8222-8986)
- Arjan Bik (ORCID: https://orcid.org/0000-0001-8068-0891)
- J. S. Gallagher (ORCID: https://orcid.org/0000-0001-8608-0408)
- L. J. Smith (ORCID: https://orcid.org/0000-0002-0806-168X)
- Sean T. Linden (ORCID: https://orcid.org/0000-0002-1000-6081)
- M. Tosi (ORCID: https://orcid.org/0000-0002-0986-4759)
- Jens Melinder (ORCID: https://orcid.org/0000-0003-0470-8754)
- Helena Faustino Vieira (ORCID: https://orcid.org/0000-0002-2199-0977)
Institutions
- University of Pisa (IT)
- Australian National University (AU)
- Space Telescope Science Institute (US)
- University of Arizona (US)
- Stockholm University (SE)
- University of Massachusetts Amherst (US)
- Astronomical Observatory of Rome (IT)
- Agenzia Spaziale Italiana (IT)
- Katonah Museum of Art (US)
- ASTRO-3D (AU)
- Gemini North Observatory (US)
- AlbaNova (SE)
- NSF NOIRLab (US)
- ARC Centre of Excellence for All-sky Astrophysics (AU)
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa (IT)
- Osservatorio di Astrofisica e Scienza dello Spazio
- University of Virginia (US)
- Macalester College (US)
- Cardiff University (GB)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2024-08-01
- DOI
- https://doi.org/10.3847/1538-4357/ad53c0
- Citations
- 8
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 2.65
Funders
- National Aeronautics and Space Administration
- California Institute of Technology
- Space Telescope Science Institute
- Australian Government
- Swedish National Space Agency
- Ministero dell’Istruzione, dell’Università e della Ricerca
- Jet Propulsion Laboratory
- Australian Research Council