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

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.; Boker, Torsten; Vivian, U.; 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
2022
ASTROPHYSICAL JOURNAL LETTERS
DOI
10.3847/2041-8213/ac9389
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 (LIR) 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 x 10(11) L-circle dot, arises from a source no larger than 175 pc in radius, suggesting a luminosity density of at least 3-5 x 10(12) Le 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.