The Astrophysical Journal (Jan 2024)
The JWST Resolved Stellar Populations Early Release Science Program. IV. The Star Formation History of the Local Group Galaxy WLM
- Kristen. B. W. McQuinn,
- Max J. B. Newman,
- Alessandro Savino,
- Andrew E. Dolphin,
- Daniel R. Weisz,
- Benjamin F. Williams,
- Martha L. Boyer,
- Roger E. Cohen,
- Matteo Correnti,
- Andrew A. Cole,
- Marla C. Geha,
- Mario Gennaro,
- Nitya Kallivayalil,
- Karin M. Sandstrom,
- Evan D. Skillman,
- Jay Anderson,
- Alberto Bolatto,
- Michael Boylan-Kolchin,
- Christopher T. Garling,
- Karoline M. Gilbert,
- Léo Girardi,
- Jason S. Kalirai,
- Alessandro Mazzi,
- Giada Pastorelli,
- Hannah Richstein,
- Jack T. Warfield
Affiliations
- Kristen. B. W. McQuinn
- ORCiD
- Rutgers University , Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway, NJ 08854, USA ; [email protected]
- Max J. B. Newman
- ORCiD
- Rutgers University , Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway, NJ 08854, USA ; [email protected]
- Alessandro Savino
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Andrew E. Dolphin
- ORCiD
- Raytheon Technologies , 1151 East Hermans Road, Tucson, AZ 85756, USA; Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85719, USA
- Daniel R. Weisz
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720, USA
- Benjamin F. Williams
- ORCiD
- Department of Astronomy, University of Washington , Box 351580, U.W., Seattle, WA 98195-1580, USA
- Martha L. Boyer
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Roger E. Cohen
- ORCiD
- Rutgers University , Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway, NJ 08854, USA ; [email protected]
- Matteo Correnti
- ORCiD
- INAF Osservatorio Astronomico di Roma , Via Frascati 33, I-00078, Monteporzio Catone, Rome, Italy; ASI-Space Science Data Center , Via del Politecnico, I-00133, Rome, Italy
- Andrew A. Cole
- ORCiD
- School of Natural Sciences, University of Tasmania , Private Bag 37, Hobart, Tasmania 7001, Australia
- Marla C. Geha
- ORCiD
- Department of Astronomy, Yale University , New Haven, CT 06520, USA
- Mario Gennaro
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; The William H. Miller III Department of Physics & Astronomy, Bloomberg Center for Physics and Astronomy, Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA
- Nitya Kallivayalil
- ORCiD
- Department of Astronomy, The University of Virginia , 530 McCormick Road, Charlottesville, VA 22904, USA
- Karin M. Sandstrom
- ORCiD
- Department of Astronomy & Astrophysics, University of California San Diego , 9500 Gilman Drive, La Jolla, CA 92093, USA
- Evan D. Skillman
- ORCiD
- University of Minnesota , Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S.E., Minneapolis, MN 55455, USA
- Jay Anderson
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Alberto Bolatto
- ORCiD
- Department of Astronomy, University of Maryland , College Park, MD 20742, USA; Joint Space-Science Institute, University of Maryland , College Park, MD 20742, USA
- Michael Boylan-Kolchin
- ORCiD
- Department of Astronomy, The University of Texas at Austin , 2515 Speedway, Stop C1400, Austin, TX 787125, USA
- Christopher T. Garling
- ORCiD
- Department of Astronomy, The University of Virginia , 530 McCormick Road, Charlottesville, VA 22904, USA
- Karoline M. Gilbert
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; The William H. Miller III Department of Physics & Astronomy, Bloomberg Center for Physics and Astronomy, Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218, USA
- Léo Girardi
- ORCiD
- Padova Astronomical Observatory , Vicolo dell’Osservatorio 5, Padova, Italy
- Jason S. Kalirai
- ORCiD
- John Hopkins Applied Physics Laboratory , 11100 Johns Hopkins Road, Laurel, MD 20723, USA
- Alessandro Mazzi
- ORCiD
- Dipartimento di Fisica e Astronomia Galileo Galilei, Università di Padova , Vicolo dell’Osservatorio 3, I-35122 Padova, Italy
- Giada Pastorelli
- ORCiD
- Padova Astronomical Observatory , Vicolo dell’Osservatorio 5, Padova, Italy
- Hannah Richstein
- ORCiD
- Department of Astronomy, The University of Virginia , 530 McCormick Road, Charlottesville, VA 22904, USA
- Jack T. Warfield
- ORCiD
- Department of Astronomy, The University of Virginia , 530 McCormick Road, Charlottesville, VA 22904, USA
- DOI
- https://doi.org/10.3847/1538-4357/ad1105
- Journal volume & issue
-
Vol. 961,
no. 1
p. 16
Abstract
We present the first star formation history (SFH) and age–metallicity relation (AMR) derived from resolved stellar populations imaged with the JWST NIRCam instrument. The target is the Local Group star-forming galaxy WLM at 970 kpc. The depth of the color–magnitude diagram (CMD) reaches below the oldest main sequence turnoff with a signal-to-noise ratio = 10 at M _F090W = + 4.6 mag. This is the deepest CMD for any galaxy that is not a satellite of the Milky Way. We use Hubble Space Telescope (HST) optical imaging that overlaps with the NIRCam observations to directly evaluate the SFHs derived based on data from the two great observatories. The JWST and HST-based SFHs are in excellent agreement. We use the metallicity distribution function measured from stellar spectra to confirm the trends in the AMRs based on the JWST data. Together, these results confirm the efficacy of recovering an SFH and AMR with the NIRCam F090W−F150W filter combination, and validate the sensitivity and accuracy of stellar evolution libraries in the near-infrared relative to the optical for SFH recovery work. From the JWST data, WLM shows an early onset to star formation, followed by an extended pause post-reionization before star formation reignites, which is qualitatively similar to what has been observed in the isolated galaxies Leo A and Aquarius. Quantitatively, 15% of the stellar mass formed in the first Gyr, while only 10% formed over the next ∼5 Gyr. The stellar mass then rapidly doubled in ∼2.5 Gyr, followed by constant star formation over the last ∼5 Gyr.
Keywords
- Stellar populations
- Local Group
- Hertzsprung Russell diagram
- James Webb Space Telescope
- Hubble Space Telescope
