GOALS-JWST: Unveiling Dusty Compact Sources in the Merging Galaxy IIZw096
Inami, Hanae; Böker, Torsten; Kemper, Francisca; Aalto, Susanne; van der Werf, Paul; Hayward, Christopher C.; Larson, Kirsten L.; Bohn, Thomas; Armus, Lee; Murphy, Eric J.; Malkan, Matthew A.; Linden, Sean T.; Stierwalt, Sabrina; Brown, Michael J. I.; Evans, Aaron S.; U, Vivian; Howell, Justin H.; Sanders, David; Surace, Jason; Rich, Jeffrey A.; Privon, George C.; Charmandaris, Vassilis; Law, David; Song, Yiqing; Appleton, Philip; Medling, Anne M.; Iwasawa, Kazushi; Marshall, Jason; Mazzarella, Joseph M.; Lai, Thomas; Barcos-Munoz, Loreto; Diaz-Santos, Tanio; Hoshioka, Shunshi
Japan, United States, Greece, Cyprus, Australia, Sweden, Spain, Netherlands
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.