The Astrophysical Journal Letters (Jan 2023)
PHANGS–JWST First Results: Massive Young Star Clusters and New Insights from JWST Observations of NGC 1365
- Bradley C. Whitmore,
- Rupali Chandar,
- M. Jimena Rodríguez,
- Janice C. Lee,
- Eric Emsellem,
- Matthew Floyd,
- Hwihyun Kim,
- J. M. Diederik Kruijssen,
- Angus Mok,
- Mattia C. Sormani,
- Médéric Boquien,
- Daniel A. Dale,
- Christopher M. Faesi,
- Kiana F. Henny,
- Stephen Hannon,
- David A. Thilker,
- Richard L. White,
- Ashley T. Barnes,
- F. Bigiel,
- Mélanie Chevance,
- Jonathan D. Henshaw,
- Ralf S. Klessen,
- Adam K. Leroy,
- Daizhong Liu,
- Daniel Maschmann,
- Sharon E. Meidt,
- Erik Rosolowsky,
- Eva Schinnerer,
- Jiayi Sun,
- Elizabeth J. Watkins,
- Thomas G. Williams
Affiliations
- Bradley C. Whitmore
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]
- Rupali Chandar
- ORCiD
- Ritter Astrophysical Research Center, University of Toledo , Toledo, OH 43606, USA
- M. Jimena Rodríguez
- ORCiD
- Steward Observatory, University of Arizona , 933 N. Cherry Avenue,Tucson, AZ 85721, USA; Instituto de Astrofisica de La Plata , CONICET-UNLP, Paseo del Bosque S/N, B1900FWA La Plata, Argentina
- Janice C. Lee
- ORCiD
- Gemini Observatory/NSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USA
- Eric Emsellem
- ORCiD
- European Southern Observatory , Karl-Schwarzschild Str. 2, D-85748 Garching bei Muenchen, Germany
- Matthew Floyd
- Ritter Astrophysical Research Center, University of Toledo , Toledo, OH 43606, USA
- Hwihyun Kim
- ORCiD
- Gemini Observatory/NSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USA
- J. M. Diederik Kruijssen
- ORCiD
- Cosmic Origins Of Life (COOL) Research DAO (coolresearch.io)
- Angus Mok
- ORCiD
- OCAD University , Toronto, ON M5T 1W1, Canada
- Mattia C. Sormani
- ORCiD
- Astronomisches Rechen-Institut , Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120 Heidelberg, Germany
- Médéric Boquien
- ORCiD
- Centro de Astronomía (CITEVA), Universidad de Antofagasta , Avenida Angamos 601, Antofagasta, Chile
- Daniel A. Dale
- ORCiD
- Department of Physics and Astronomy, University of Wyoming , Laramie, WY 82071, USA
- Christopher M. Faesi
- ORCiD
- University of Connecticut , Department of Physics, 196A Auditorium Road, Unit 3046, Storrs, CT 06269, USA
- Kiana F. Henny
- ORCiD
- Department of Physics and Astronomy, University of Wyoming , Laramie, WY 82071, USA
- Stephen Hannon
- Department of Physics and Astronomy, University of California , Riverside, CA, 92521 USA
- David A. Thilker
- ORCiD
- Department of Physics and Astronomy, The Johns Hopkins University , Baltimore, MD 21218 USA
- Richard L. White
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA ; [email protected]
- Ashley T. Barnes
- ORCiD
- Argelander-Institut für Astronomie, Universität Bonn , Auf dem Hügel 71, D-53121, Bonn, Germany
- F. Bigiel
- ORCiD
- Argelander-Institut für Astronomie, Universität Bonn , Auf dem Hügel 71, D-53121, Bonn, Germany
- Mélanie Chevance
- ORCiD
- Cosmic Origins Of Life (COOL) Research DAO (coolresearch.io); Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg , Albert-Ueberle-Strasse 2, D-69120 Heidelberg, Germany
- Jonathan D. Henshaw
- ORCiD
- Astrophysics Research Institute, Liverpool John Moores University , 146 Brownlow Hill, Liverpool L3 5RF, UK; Max Planck Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg, Germany
- Ralf S. Klessen
- ORCiD
- Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg , Albert-Ueberle-Strasse 2, D-69120 Heidelberg, Germany; Universität Heidelberg , Interdisziplinäres Zentrum für Wissenschaftliches Rechnen, Im Neuenheimer Feld 205, D-69120 Heidelberg, Germany
- Adam K. Leroy
- ORCiD
- Department of Astronomy, The Ohio State University , 140 West 18th Avenue, Columbus, OH 43210, USA
- Daizhong Liu
- ORCiD
- Max-Planck-Institut für Extraterrestrische Physik (MPE) , Giessenbachstr. 1, D-85748 Garching, Germany
- Daniel Maschmann
- ORCiD
- Steward Observatory, University of Arizona , 933 N. Cherry Avenue,Tucson, AZ 85721, USA; Sorbonne Université , LERMA, Observatoire de Paris, PSL university, CNRS, F-75014 Paris, France
- Sharon E. Meidt
- ORCiD
- Sterrenkundig Observatorium, Universiteit Gent , Krijgslaan 281 S9, B-9000 Gent, Belgium
- Erik Rosolowsky
- ORCiD
- Department of Physics, University of Alberta , Edmonton, AB T6G 2E1, Canada
- Eva Schinnerer
- ORCiD
- Max Planck Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg, Germany
- Jiayi Sun
- ORCiD
- Canadian Institute for Theoretical Astrophysics (CITA), University of Toronto , 60 St George Street, Toronto, ON M5S 3H8, Canada; Department of Physics and Astronomy, McMaster University , 1280 Main Street West, Hamilton, ON L8S 4M1, Canada
- Elizabeth J. Watkins
- ORCiD
- Astronomisches Rechen-Institut , Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120 Heidelberg, Germany
- Thomas G. Williams
- ORCiD
- Max Planck Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg, Germany
- DOI
- https://doi.org/10.3847/2041-8213/acae94
- Journal volume & issue
-
Vol. 944,
no. 2
p. L14
Abstract
A primary new capability of JWST is the ability to penetrate the dust in star-forming galaxies to identify and study the properties of young star clusters that remain embedded in dust and gas. In this Letter we combine new infrared images taken with JWST with our optical Hubble Space Telescope (HST) images of the starbursting barred (Seyfert2) spiral galaxy NGC 1365. We find that this galaxy has the richest population of massive young clusters of any known galaxy within 30 Mpc, with ∼30 star clusters that are more massive than 10 ^6 M _⊙ and younger than 10 Myr. Sixteen of these clusters are newly discovered from our JWST observations. An examination of the optical images reveals that 4 of 30 (∼13%) are so deeply embedded that they cannot be seen in the Hubble I band ( A _V ≳ 10 mag), and that 11 of 30 (∼37%) are missing in the HST B band, so age and mass estimates from optical measurements alone are challenging. These numbers suggest that massive clusters in NGC 1365 remain completely obscured in the visible for ∼1.3 ± 0.7 Myr and are either completely or partially obscured for ∼3.7 ± 1.1 Myr. We also use the JWST observations to gain new insights into the triggering of star cluster formation by the collision of gas and dust streamers with gas and dust in the bar. The JWST images reveal previously unknown structures (e.g., bridges and overshoot regions from stars that form in the bar) that help us better understand the orbital dynamics of barred galaxies and associated star-forming rings. Finally, we note that the excellent spatial resolution of the NIRCAM F200W filter provides a better way to separate barely resolved compact clusters from individual stars based on their sizes.
Keywords