GOALS-JWST: Revealing the Buried Star Clusters in the Luminous Infrared Galaxy VV 114

February 2023 • 2023ApJ...944L..55L

Authors • Linden, Sean T. • Evans, Aaron S. • Armus, Lee • Rich, Jeffrey A. • Larson, Kirsten L. • Lai, Thomas • Privon, George C. • U, Vivian • Inami, Hanae • Bohn, Thomas • Song, Yiqing • Barcos-Muñoz, Loreto • Charmandaris, Vassilis • Medling, Anne M. • Stierwalt, Sabrina • Diaz-Santos, Tanio • Böker, Torsten • van der Werf, Paul • Aalto, Susanne • Appleton, Philip • Brown, Michael J. I. • Hayward, Christopher C. • Howell, Justin H. • Iwasawa, Kazushi • Kemper, Francisca • Frayer, David T. • Law, David • Malkan, Matthew A. • Marshall, Jason • Mazzarella, Joseph M. • Murphy, Eric J. • Sanders, David • Surace, Jason

Abstract • We present the results of a James Webb Space Telescope NIRCam investigation into the young massive star cluster (YMC) population in the luminous infrared galaxy VV 114. We identify 374 compact YMC candidates with signal-to-noise ratios ≥ 3, 5, and 5 at F150W, F200W, and F356W, respectively. A direct comparison with our HST cluster catalog reveals that ~20% of these sources are undetected at optical wavelengths. Based on yggdrasil stellar population models, we identify 17 YMC candidates in our JWST imaging alone with F150W - F200W and F200W - F356W colors suggesting they are all very young, dusty (A _V = 5-15), and massive (10^5.8 < M _⊙ < 10^6.1). The discovery of these "hidden" sources, many of which are found in the "overlap" region between the two nuclei, quadruples the number of t < 3 Myr clusters and nearly doubles the number of t < 6 Myr clusters detected in VV 114. Now extending the cluster age distribution ( ${dN}/d\tau \propto {\tau }^{\gamma }$ ) to the youngest ages, we find a slope of γ = -1.30 ± 0.39 for 10⁶ < τ(yr) < 10⁷, which is consistent with the previously determined value from 10⁷ < τ(yr) < 10^8.5, and confirms that VV 114 has a steep age distribution slope for all massive star clusters across the entire range of cluster ages observed. Finally, the consistency between our JWST- and HST-derived age distribution slopes indicates that the balance between cluster formation and destruction has not been significantly altered in VV 114 over the last 0.5 Gyr.

Links

• PREPRINT http://arxiv.org/abs/2210.05763
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2023ApJ...944L..55L
• ELECTR https://iopscience.iop.org/article/10.3847/2041-8213/acb335
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2023ApJ...944L..55L
• PDF https://iopscience.iop.org/article/10.3847/2041-8213/acb335/pdf
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2023ApJ...944L..55L
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