The Astrophysical Journal Letters (Jan 2023)
PHANGS–JWST First Results: Destruction of the PAH Molecules in H ii Regions Probed by JWST and MUSE
- Oleg V. Egorov,
- Kathryn Kreckel,
- Karin M. Sandstrom,
- Adam K. Leroy,
- Simon C. O. Glover,
- Brent Groves,
- J. M. Diederik Kruijssen,
- Ashley. T. Barnes,
- Francesco Belfiore,
- F. Bigiel,
- Guillermo A. Blanc,
- Médéric Boquien,
- Yixian Cao,
- Jérémy Chastenet,
- Mélanie Chevance,
- Enrico Congiu,
- Daniel A. Dale,
- Eric Emsellem,
- Kathryn Grasha,
- Ralf S. Klessen,
- Kirsten L. Larson,
- Daizhong Liu,
- Eric J. Murphy,
- Hsi-An Pan,
- Ismael Pessa,
- Jérôme Pety,
- Erik Rosolowsky,
- Fabian Scheuermann,
- Eva Schinnerer,
- Jessica Sutter,
- David A. Thilker,
- Elizabeth J. Watkins,
- Thomas G. Williams
Affiliations
- Oleg V. Egorov
- ORCiD
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg , Mönchhofstraße 12–14, D-69120 Heidelberg, Germany [email protected]
- Kathryn Kreckel
- ORCiD
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg , Mönchhofstraße 12–14, D-69120 Heidelberg, Germany [email protected]
- Karin M. Sandstrom
- ORCiD
- Center for Astrophysics & Space Sciences, Department of Physics, University of California , San Diego, 9500 Gilman Drive, San Diego, CA 92093, USA
- Adam K. Leroy
- ORCiD
- Department of Astronomy, The Ohio State University , 140 West 18th Avenue, Columbus, OH 43210, USA
- Simon C. O. Glover
- ORCiD
- Universität Heidelberg , Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Str 2, D-69120 Heidelberg, Germany
- Brent Groves
- ORCiD
- International Centre for Radio Astronomy Research, University of Western Australia , 35 Stirling Highway, Crawley, WA 6009, Australia
- J. M. Diederik Kruijssen
- ORCiD
- Cosmic Origins Of Life (COOL) Research DAO 29
- Ashley. T. Barnes
- ORCiD
- Argelander-Institut für Astronomie, Universität Bonn , Auf dem Hügel 71, D-53121 Bonn, Germany
- Francesco Belfiore
- ORCiD
- INAF—Osservatorio Astrofisico di Arcetri , Largo E. Fermi 5, I-50157, Florence, Italy
- F. Bigiel
- ORCiD
- Argelander-Institut für Astronomie, Universität Bonn , Auf dem Hügel 71, D-53121 Bonn, Germany
- Guillermo A. Blanc
- ORCiD
- Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA; Departamento de Astronomía, Universidad de Chile , Camino del Observatorio 1515, Las Condes, Santiago, Chile
- Médéric Boquien
- ORCiD
- Centro de Astronomía (CITEVA), Universidad de Antofagasta , Avenida Angamos 601, Antofagasta, Chile
- Yixian Cao
- ORCiD
- Max-Planck-Institut für extraterrestrische Physik , Giessenbachstraße 1, D-85748 Garching, Germany
- Jérémy Chastenet
- ORCiD
- Sterrenkundig Observatorium, Universiteit Gent , Krijgslaan 281 S9, B-9000 Gent, Belgium
- Mélanie Chevance
- ORCiD
- Universität Heidelberg , Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Str 2, D-69120 Heidelberg, Germany; Cosmic Origins Of Life (COOL) Research DAO 29
- Enrico Congiu
- ORCiD
- Departamento de Astronomía, Universidad de Chile , Camino del Observatorio 1515, Las Condes, Santiago, Chile
- Daniel A. Dale
- ORCiD
- Department of Physics and Astronomy, University of Wyoming , Laramie, WY 82071, USA
- Eric Emsellem
- ORCiD
- European Southern Observatory, Karl-Schwarzschild Straße 2, D-85748 Garching bei München, Germany; Univ Lyon , Univ Lyon 1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230 Saint-Genis-Laval, France
- Kathryn Grasha
- ORCiD
- Research School of Astronomy and Astrophysics, Australian National University , Canberra, ACT 2611, Australia
- Ralf S. Klessen
- ORCiD
- Universität Heidelberg , Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Ueberle-Str 2, D-69120 Heidelberg, Germany; Universität Heidelberg , Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Im Neuenheimer Feld 205, D-69120 Heidelberg, Germany
- Kirsten L. Larson
- ORCiD
- AURA for the European Space Agency (ESA), Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Daizhong Liu
- ORCiD
- Max-Planck-Institut für extraterrestrische Physik , Giessenbachstraße 1, D-85748 Garching, Germany
- Eric J. Murphy
- ORCiD
- National Radio Astronomy Observatory , 520 Edgemont Road, Charlottesville, VA 22903-2475, USA
- Hsi-An Pan
- ORCiD
- Department of Physics, Tamkang University , No. 151, Yingzhuan Road, Tamsui District, New Taipei City 251301, Taiwan
- Ismael Pessa
- ORCiD
- Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany
- Jérôme Pety
- ORCiD
- Institut de Radioastronomie Millimétrique (IRAM) , 300 Rue de la Piscine, F-38406 Saint Martin d’Hères, France; LERMA, Observatoire de Paris, PSL Research University , CNRS, Sorbonne Universités, F-75014 Paris, France
- Erik Rosolowsky
- ORCiD
- Department of Physics, University of Alberta , Edmonton, AB T6G 2E1, Canada
- Fabian Scheuermann
- ORCiD
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg , Mönchhofstraße 12–14, D-69120 Heidelberg, Germany [email protected]
- Eva Schinnerer
- ORCiD
- Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany
- Jessica Sutter
- ORCiD
- Center for Astrophysics & Space Sciences, Department of Physics, University of California , San Diego, 9500 Gilman Drive, San Diego, CA 92093, USA; Leibniz-Institut für Astrophysik Potsdam (AIP) , An der Sternwarte 16, D-14482 Potsdam, Germany
- David A. Thilker
- ORCiD
- Department of Physics and Astronomy, The Johns Hopkins University , Baltimore, MD 21218, USA
- Elizabeth J. Watkins
- ORCiD
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg , Mönchhofstraße 12–14, D-69120 Heidelberg, Germany [email protected]
- Thomas G. Williams
- ORCiD
- Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany; Sub-department of Astrophysics, Department of Physics, University of Oxford , Keble Road, Oxford OX1 3RH, UK
- DOI
- https://doi.org/10.3847/2041-8213/acac92
- Journal volume & issue
-
Vol. 944,
no. 2
p. L16
Abstract
Polycyclic aromatic hydrocarbons (PAHs) play a critical role in the reprocessing of stellar radiation and balancing the heating and cooling processes in the interstellar medium but appear to be destroyed in H ii regions. However, the mechanisms driving their destruction are still not completely understood. Using PHANGS–JWST and PHANGS–MUSE observations, we investigate how the PAH fraction changes in about 1500 H ii regions across four nearby star-forming galaxies (NGC 628, NGC 1365, NGC 7496, and IC 5332). We find a strong anticorrelation between the PAH fraction and the ionization parameter (the ratio between the ionizing photon flux and the hydrogen density) of H ii regions. This relation becomes steeper for more luminous H ii regions. The metallicity of H ii regions has only a minor impact on these results in our galaxy sample. We find that the PAH fraction decreases with the H α equivalent width—a proxy for the age of the H ii regions—although this trend is much weaker than the one identified using the ionization parameter. Our results are consistent with a scenario where hydrogen-ionizing UV radiation is the dominant source of PAH destruction in star-forming regions.
Keywords
