GOALS-JWST: Hidden Star Formation and Extended PAH Emission in the Luminous Infrared Galaxy VV 114

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

Research output: Contribution to journalArticleResearchpeer-review

Abstract

James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) images of the luminous infrared (IR) galaxy VV 114 are presented. This redshift ∼0.020 merger has a western component (VV 114W) rich in optical star clusters and an eastern component (VV 114E) hosting a luminous mid-IR nucleus hidden at UV and optical wavelengths by dust lanes. With MIRI, the VV 114E nucleus resolves primarily into bright NE and SW cores separated by 630 pc. This nucleus comprises 45% of the 15 μm light of VV 114, with the NE and SW cores having IR luminosities, L IR(8 − 1000 μm) ∼ 8 ± 0.8 × 1010 L and ∼ 5 ± 0.5 × 1010 L , respectively, and IR densities, ΣIR ≳ 2 ± 0.2 × 1013 L kpc−2 and ≳ 7 ± 0.7 × 1012 L kpc−2, respectively—in the range of ΣIR for the Orion star-forming core and the nuclei of Arp 220. The NE core, previously speculated to have an active galactic nucleus (AGN), has starburst-like mid-IR colors. In contrast, the VV 114E SW core has AGN-like colors. Approximately 40 star-forming knots with L IR ∼ 0.02-5 × 1010 L are identified, 28% of which have no optical counterpart. Finally, diffuse emission accounts for 40%-60% of the mid-IR emission. Mostly notably, filamentary polycyclic aromatic hydrocarbon (PAH) emission stochastically excited by UV and optical photons accounts for half of the 7.7 μm light of VV 114. This study illustrates the ability of JWST to detect obscured compact activity and distributed PAH emission in the most extreme starburst galaxies in the local universe.

Original languageEnglish
Article numberL8
Number of pages7
JournalThe Astrophysical Journal Letters
Volume940
Issue number1
DOIs
Publication statusPublished - 1 Nov 2022
  • ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions

    Kewley, L. (Primary Chief Investigator (PCI)), Stuart B Wyithe, J. (Chief Investigator (CI)), Sadler, E. (Chief Investigator (CI)), Staveley-Smith, L. (Chief Investigator (CI)), Glazebrook, K. (Chief Investigator (CI)), Jackson, C. (Chief Investigator (CI)), Bland-Hawthorn, J. (Chief Investigator (CI)), Asplund, M. B. (Chief Investigator (CI)), Trott, C. M. (Chief Investigator (CI)), Webster, R. (Chief Investigator (CI)), trenti, M. (Chief Investigator (CI)), Colless, M. (Chief Investigator (CI)), Croom, S. (Chief Investigator (CI)), Ryan-Weber, E. V. (Chief Investigator (CI)), Power, C. (Chief Investigator (CI)), Croton, D. J. (Chief Investigator (CI)), Driver, S. (Chief Investigator (CI)), Abraham, R. (Partner Investigator (PI)), Ball, L. (Partner Investigator (PI)), Bunker, A. (Partner Investigator (PI)), Couch, W. (Partner Investigator (PI)), Dalcanton, J. (Partner Investigator (PI)), Davies, R. L. (Partner Investigator (PI)), Gaensler, B. M. (Partner Investigator (PI)), Hopkins, A. (Partner Investigator (PI)), Kirby, E. (Partner Investigator (PI)), Koribalski, B. (Partner Investigator (PI)), Li, D. (Partner Investigator (PI)), Martin, D. C. (Partner Investigator (PI)), Morales, M. F. (Partner Investigator (PI)), Morganti, R. (Partner Investigator (PI)), Springel, V. (Partner Investigator (PI)), Wise, M. W. (Partner Investigator (PI)) & Karakas, A. (Chief Investigator (CI))

    Monash University – Internal Faculty Contribution

    30/06/1731/12/24

    Project: Research

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