Feedback in Emerging Extragalactic Star Clusters, FEAST: The Relation between 3.3 μm Polycyclic Aromatic Hydrocarbon Emission and Star Formation Rate Traced by Ionized Gas in NGC 628

Bibliographic Details
Title: Feedback in Emerging Extragalactic Star Clusters, FEAST: The Relation between 3.3 μm Polycyclic Aromatic Hydrocarbon Emission and Star Formation Rate Traced by Ionized Gas in NGC 628
Authors: Benjamin Gregg, Daniela Calzetti, Angela Adamo, Varun Bajaj, Jenna E. Ryon, Sean T. Linden, Matteo Correnti, Michele Cignoni, Matteo Messa, Elena Sabbi, John S. Gallagher, Kathryn Grasha, Alex Pedrini, Robert A. Gutermuth, Jens Melinder, Ralf Kotulla, Gustavo Pérez, Mark R. Krumholz, Arjan Bik, Göran Östlin, Kelsey E. Johnson, Giacomo Bortolini, Linda J. Smith, Monica Tosi, Subhransu Maji, Helena Faustino Vieira
Source: The Astrophysical Journal, Vol 971, Iss 1, p 115 (2024)
Publisher Information: IOP Publishing, 2024.
Publication Year: 2024
Collection: LCC:Astrophysics
Subject Terms: Spiral galaxies, Interstellar dust, Interstellar medium, James Webb Space Telescope, Polycyclic aromatic hydrocarbons, Star formation, Astrophysics, QB460-466
More Details: We present maps of ionized gas (traced by Pa α and Br α ) and 3.3 μ m polycyclic aromatic hydrocarbon (PAH) emission in the nearby spiral galaxy NGC 628, derived from new JWST/NIRCam data from the Feedback in Emerging extrAgalactic Star clusTers (FEAST) survey. With this data, we investigate and calibrate the relation between 3.3 μ m PAH emission and star formation rate (SFR) in and around emerging young star clusters (eYSCs) on a scale of ∼40 pc. We find a tight (correlation coefficient ρ ∼ 0.9) sublinear (power-law exponent α ∼ 0.75) relation between the 3.3 μ m PAH luminosity surface density and SFR traced by Br α for compact, cospatial (within 0.″16 or ∼7 pc) peaks in Pa α , Br α , and 3.3 μ m (eYSC–I). The scatter in the relationship does not correlate well with variations in local interstellar medium metallicity, due to a radial metallicity gradient, but rather is likely due to stochastic sampling of the stellar initial mass function (IMF) and variations in the PAH heating and age of our sources. The deviation from a linear relation may be explained by PAH destruction in more intense ionizing environments, variations in age, and IMF stochasticity at intermediate to low luminosities. We test our results with various continuum subtraction techniques using combinations of NIRCam bands and find that they remain robust with only minor differences in the derived slope and intercept. An unexpected discrepancy is identified between the relations of hydrogen recombination lines (Pa α versus Br α ; H α versus Br α ).
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1538-4357
Relation: https://doaj.org/toc/1538-4357
DOI: 10.3847/1538-4357/ad54b4
Access URL: https://doaj.org/article/385c1b82d6d5430e93e77d9aea6bb156
Accession Number: edsdoj.385c1b82d6d5430e93e77d9aea6bb156
Database: Directory of Open Access Journals
More Details
ISSN:15384357
DOI:10.3847/1538-4357/ad54b4
Published in:The Astrophysical Journal
Language:English