Imaging of I Zw 18 by JWST. I. Detecting Dusty Stellar Populations
Artikel i vetenskaplig tidskrift, 2024
We present a JWST imaging survey of I Zw 18, the archetypal extremely metal-poor, star-forming (SF), blue compact dwarf galaxy. With an oxygen abundance of only similar to 3% Z circle dot, it is among the lowest-metallicity systems known in the local Universe, and is, therefore, an excellent accessible analog for the galactic building blocks which existed at early epochs of ionization and star formation. These JWST data provide a comprehensive infrared (IR) view of I Zw 18 with eight filters utilizing both Near Infrared Camera (F115W, F200W, F356W, and F444W) and Mid-Infrared Instrument (F770W, F1000W, F1500W, and F1800W) photometry, which we have used to identify key stellar populations that are bright in the near- and mid-IR. These data allow for a better understanding of the origins of dust and dust-production mechanisms in metal-poor environments by characterizing the population of massive, evolved stars in the red supergiant (RSG) and asymptotic giant branch (AGB) phases. In addition, it enables the identification of the brightest dust-enshrouded young stellar objects (YSOs), which provide insight into the formation of massive stars at extremely low metallicities typical of the very early Universe. This paper provides an overview of the observational strategy and data processing, and presents first science results, including identifications of dusty AGB, RSG, and bright YSO candidates. These first results assess the scientific quality of JWST data and provide a guide for obtaining and interpreting future observations of the dusty and evolved stars inhabiting compact dwarf SF galaxies in the local Universe.
Författare
Alec S. Hirschauer
Space Telescope Science Institute (STScI)
Nicolas Crouzet
Universiteit Leiden
Nolan Habel
California Institute of Technology (Caltech)
Laura Lenkic
NASA Ames Research Center
California Institute of Technology (Caltech)
Conor Nally
University of Edinburgh
Olivia C. Jones
UK Astronomy Technology Centre
Giacomo Bortolini
Stockholms universitet
Martha L. Boyer
Space Telescope Science Institute (STScI)
Kay Justtanont
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Margaret Meixner
California Institute of Technology (Caltech)
Goran Ostlin
Stockholms universitet
Gillian S. Wright
UK Astronomy Technology Centre
Ruyman Azzollini
University College London (UCL)
Joris A. D. L. Blommaert
Vrije Universiteit Brüssel (VUB)
Bernhard Brandl
Universiteit Leiden
Leen Decin
KU Leuven
Omnarayani Nayak
NASA Goddard Space Flight Center
Space Telescope Science Institute (STScI)
Pierre Royer
KU Leuven
B. A. Sargent
Space Telescope Science Institute (STScI)
Johns Hopkins University
Paul van der Werf
Universiteit Leiden
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 168 1 23Ämneskategorier (SSIF 2011)
Astronomi, astrofysik och kosmologi
Datorseende och robotik (autonoma system)
DOI
10.3847/1538-3881/ad4967