GOALS-JWST: Unveiling Dusty Compact Sources in the Merging Galaxy IIZw096

November 2022 • 2022ApJ...940L...6I

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

Abstract • We have used the Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) to obtain the first spatially resolved, mid-infrared images of IIZw096, a merging luminous infrared galaxy (LIRG) at z = 0.036. Previous observations with the Spitzer Space Telescope suggested that the vast majority of the total IR luminosity (L IR) of the system originated from a small region outside of the two merging nuclei. New observations with JWST/MIRI now allow an accurate measurement of the location and luminosity density of the source that is responsible for the bulk of the IR emission. We estimate that 40%-70% of the IR bolometric luminosity, or 3-5 × 1011 L , arises from a source no larger than 175 pc in radius, suggesting a luminosity density of at least 3-5 × 1012 L kpc-2. In addition, we detect 11 other star-forming sources, five of which were previously unknown. The MIRI F1500W/F560W colors of most of these sources, including the source responsible for the bulk of the far-IR emission, are much redder than the nuclei of local LIRGs. These observations reveal the power of JWST to disentangle the complex regions at the hearts of merging, dusty galaxies.


IPAC Authors


Phil Appleton

Senior Scientist


Lee Armus

Senior Scientist

Joe Mazzarella

Senior Scientist