CaltechAUTHORS
Published February 1, 2019 | Version Published
Journal Article Open

Keck OSIRIS AO LIRG Analysis (KOALA): Feedback in the Nuclei of Luminous Infrared Galaxies

Creators

  • 1. ROR icon University of California, Irvine
  • 2. ROR icon University of Toledo
  • 3. ROR icon California Institute of Technology
  • 4. ROR icon Australian National University
  • 5. ROR icon Centre for Astronomical Reseach of Lyon
  • 6. ROR icon Diego Portales University
  • 7. ROR icon University of Crete
  • 8. ROR icon National Observatory of Athens
  • 9. ROR icon Infrared Processing and Analysis Center
  • 10. ROR icon University of Florida
  • 11. ROR icon University of Virginia
  • 12. ROR icon University of Hawaii at Manoa
  • 13. ROR icon University of California, Santa Cruz
  • 14. ROR icon National Radio Astronomy Observatory
  • 15. ROR icon Atacama Large Millimeter Submillimeter Array
  • 16. ROR icon University of Southern California
  • 17. ROR icon University of California, Riverside
  • 18. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 19. ROR icon University of Barcelona
  • 20. ROR icon Carnegie Observatories

Abstract

The role of feedback in triggering or quenching star formation and hence driving galaxy evolution can be directly studied with high-resolution integral field observations. The manifestation of feedback in shocks is particularly important to examine in galaxy mergers, where violent interactions of gas take place in the interstellar medium during the course of the galactic collision. As part of our effort to systematically study the local population of luminous infrared galaxies within the Great Observatories All-Sky LIRG Survey, we undertook the Keck OSIRIS AO LIRG Analysis observing campaign to study the gas dynamics in the inner kiloparsec regions of these systems at spatial scales of a few tens of pc. With high-resolution near-infrared adaptive optics–assisted integral field observations taken with OSIRIS on the Keck Telescopes, we employ near-infrared diagnostics such as Brγ and the rovibrationally excited H_2 lines to quantify the nuclear star formation rate and identify feedback associated with shocked molecular gas seen in 21 nearby luminous infrared galaxies. Shocked molecular gas is preferentially found in the ultraluminous infrared systems but may also be triggered at a lower-luminosity, earlier merging stage. On circumnuclear scales, AGNs have a strong effect on heating the surrounding molecular gas, though their coupling is not simply driven by AGN strength but rather is complicated by orientation, dust shielding, density, and other factors. We find that nuclear star formation correlates with merger class and diminishing projected nuclear separations. These trends are largely consistent with the picture of merger-induced starbursts in the center of galaxy mergers.

Additional Information

© 2019. The American Astronomical Society. Received 2018 August 1; revised 2018 November 8; accepted 2018 November 16; published 2019 January 29. We thank the anonymous referee and the statistical editor for thoughtful suggestions that significantly improved our manuscript. We appreciate informative discussions with B. Groves and P. Creasey regarding photoionization models and wish to acknowledge helpful communication with D. Calzetti regarding dust extinction curves. We thank all of the Keck staff for help with carrying out the observations. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We also acknowledge the Evans Remote Observing Room at UC Irvine for a number of the remote observing sessions carried out there. VU acknowledges funding support from the University of California Chancellor's Postdoctoral Fellowship, JPL Contract/IRAC GTO grant No. 1256790, and NSF grant AST-1412693. Support for AMM is provided by NASA through Hubble Fellowship grant #HST-HF2-51377, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. TD-S acknowledges support from ALMA-CONICYT project 31130005 and FONDECYT project 1151239. GCP acknowledges support from the University of Florida. This work was conducted in part at the Aspen Center for Physics, which is supported by NSF grant PHY-1607611; we thank the center for its hospitality during the Astrophysics of Massive Black Hole Mergers workshop in 2018 June and July. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Facilities: Keck: I/II (OSIRIS - , AO) - .

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Additional details

Identifiers

Eprint ID
92529
Resolver ID
CaltechAUTHORS:20190130-121937282

Funding

W. M. Keck Foundation
University of California
NASA
1256790
NSF
AST-1412693
NASA Hubble Fellowship
HST-HF2-51377
NASA
NAS5-26555
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
31130005
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)
1151239
University of Florida
NSF
PHY-1607611
NASA/JPL/Caltech

Dates

Created
2019-01-31
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)