GOALS-JWST: NIRCam and MIRI Imaging of the Circumnuclear Starburst Ring in NGC 7469

January 2023 • 2023ApJ...942L..36B

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

Abstract • We present James Webb Space Telescope (JWST) imaging of NGC 7469 with the Near-Infrared Camera and the Mid-InfraRed Instrument. NGC 7469 is a nearby, z = 0.01627, luminous infrared galaxy that hosts both a Seyfert Type-1.5 nucleus and a circumnuclear starburst ring with a radius of ~0.5 kpc. The new near-infrared (NIR) JWST imaging reveals 66 star-forming regions, 37 of which were not detected by Hubble Space Telescope (HST) observations. Twenty-eight of the 37 sources have very red NIR colors that indicate obscurations up to A v ~ 7 and a contribution of at least 25% from hot dust emission to the 4.4 μm band. Their NIR colors are also consistent with young (<5 Myr) stellar populations and more than half of them are coincident with the mid-infrared (MIR) emission peaks. These younger, dusty star-forming regions account for ~6% and ~17% of the total 1.5 and 4.4 μm luminosity of the starburst ring, respectively. Thanks to JWST, we find a significant number of young dusty sources that were previously unseen due to dust extinction. The newly identified 28 young sources are a significant increase compared to the number of HST-detected young sources (4-5). This makes the total percentage of the young population rise from ~15% to 48%. These results illustrate the effectiveness of JWST in identifying and characterizing previously hidden star formation in the densest star-forming environments around active galactic nuclei (AGN).