FEAST: JWST Uncovers the Emerging Timescales of Young Star Clusters in M83
Journal article, 2025
We present JWST NIRCam observations of the emerging young star clusters (eYSCs) detected in the nearby spiral galaxy M83. The NIRcam mosaic encompasses the nuclear starburst, the bar, and the inner spiral arms. The eYSCs, detected in Paα and Brα maps, have been largely missed in previous optical campaigns of young star clusters (YSCs). We distinguish between eYSCI, if they also have compact 3.3 μm polycyclic aromatic hydrocarbon (PAH) emission associated with them, and eYSCII, if they only appear as compact Paα emitters. We find that the variations in the 3.3 μm PAH feature are consistent with an evolutionary sequence where eYSCI evolve into eYSCII and then optical YSCs. This sequence is clear in the F300M−F335M (tracing the excess in the 3.3 μm PAH feature) and the F115W−F187N (tracing the excess in Paα) colors, which become increasingly bluer as clusters emerge. The central starburst stands out as the region where the most massive eYSCs are currently forming in the galaxy. We estimate that only about 20% of eYSCs will remain detectable as compact YSCs. Combining eYSCs and YSCs (≤10 Myr), we recover an average clearing timescale of 6 Myr in which clusters transition from embedded to fully exposed. We see evidence of shorter emergence timescales (∼5 Myr) for more massive (>5 × 103 M ⊙) clusters, while star clusters of ∼103 M ⊙ about 7 Myr. We estimate that eYSCs remain associated with the 3.3 μm PAH emission for 3–4 Myr. Larger samples of eYSC and YSC populations will provide stronger statistics to further test environmental and cluster mass dependencies on the emergence timescale.
Author
Alice Knutas
Oskar Klein Centre
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
A. Adamo
Oskar Klein Centre
Alex Pedrini
Oskar Klein Centre
S. T. Linden
University of Arizona
V. Bajaj
Space Telescope Science Institute (STScI)
J. E. Ryon
Space Telescope Science Institute (STScI)
Benjamin Gregg
University of Massachusetts
Ahmad A. Ali
University of Cologne
Eric P. Andersson
American Museum of Natural History
A. Bik
Oskar Klein Centre
Giacomo Bortolini
Oskar Klein Centre
Anne S.M. Buckner
Cardiff University
D. Calzetti
University of Massachusetts
A. Duarte-Cabral
Cardiff University
Bruce G Elmegreen
Helena Faustino Vieira
Oskar Klein Centre
John S. Gallagher
University of Wisconsin
Kathryn Grasha
Australian National University
ARC Centre of Excellence for All-sky Astrophysics
Kelsey Johnson
University of Virginia
Thomas Lai
California Institute of Technology (Caltech)
Drew Lapeer
University of Massachusetts
M. Messa
Istituto nazionale di astrofisica (INAF)
G. Östlin
Oskar Klein Centre
E. Sabbi
United States Gemini Office
L. J. Smith
Space Telescope Science Institute (STScI)
Monica Tosi
Istituto nazionale di astrofisica (INAF)
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 993 1 13Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/1538-4357/ae018c