CaltechAUTHORS
Published January 1, 2017 | Version Accepted Version + Published
Journal Article Open

The Spatially Resolved [CII] Cooling Line Deficit in Galaxies

Creators

  • 1. ROR icon University of Toledo
  • 2. ROR icon Max Planck Institute for Astronomy
  • 3. ROR icon The Ohio State University
  • 4. ROR icon Princeton University
  • 5. ROR icon University of Cambridge
  • 6. ROR icon University of California, San Diego
  • 7. ROR icon California Institute of Technology
  • 8. ROR icon Paris Observatory
  • 9. ROR icon University of Maryland, College Park
  • 10. ROR icon University of Antofagasta
  • 11. ROR icon Leiden University
  • 12. ROR icon Delft University of Technology
  • 13. ROR icon Reed College
  • 14. ROR icon University of Wyoming
  • 15. ROR icon European Southern Observatory
  • 16. ROR icon Australian National University
  • 17. ROR icon Infrared Processing and Analysis Center
  • 18. ROR icon Max Planck Institute for Extraterrestrial Physics
  • 19. ROR icon Arcetri Astrophysical Observatory

Abstract

We present [C II] 158 μm measurements from over 15,000 resolved regions within 54 nearby galaxies of the Kingfish program to investigate the so-called [C II] "line-cooling deficit" long known to occur in galaxies with different luminosities. The [C II]/TIR ratio ranges from above 1% to below 0.1% in the sample, with a mean value of 0.48 ± 0.21%. We find that the surface density of 24 μm emission dominates this trend, with [C II]/TIR dropping as νl_ν (24 µm) increases. Deviations from this overall decline are correlated with changes in the gas-phase metal abundance, with higher metallicity associated with deeper deficits at a fixed surface brightness. We supplement the local sample with resolved [C II] measurements from nearby luminous infrared galaxies and high-redshift sources from z = 1.8–6.4, and find that star formation rate density drives a continuous trend of deepening [C II] deficit across six orders of magnitude in Σ_(SFR). The tightness of this correlation suggests that an approximate Σ_(SFR) can be estimated directly from global measurements of [C II]/TIR, and a relation is provided to do so. Several low-luminosity active galactic nucleus (AGN) hosts in the sample show additional and significant central suppression of [C II]/TIR, but these deficit enhancements occur not in those AGNs with the highest X-ray luminosities, but instead those with the highest central starlight intensities. Taken together, these results demonstrate that the [C II] line-cooling line deficit in galaxies likely arises from local physical phenomena in interstellar gas.

Additional Information

© 2016. The American Astronomical Society. Received 2016 July 1; revised 2016 November 2; accepted 2016 November 3; published 2016 December 22. This work is based in part on observations made with Herschel, a European Space Agency Cornerstone Mission with significant participation by NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. We thank Steve Hailey-Dunsheath, T. Rawle, and Tanio Diaz-Santos for advanced access to their compiled [C II] data sets. We also thank them, as well as Gordon Stacey, Carl Ferkinhoff, M. Kapala, and R. Decarli, for helpful discussions which improved this work. J.D.S. gratefully acknowledges visiting support from the Alexander von Humboldt Foundation and the Max Planck Institute für Astronomie as well as support from the Research Corporation for Science Advancement through its Cottrell Scholars program.

Attached Files

Published - Smith_2017_ApJ_834_5.pdf

Accepted Version - 1611.01521.pdf

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1611.01521.pdf

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Additional details

Identifiers

Eprint ID
74264
Resolver ID
CaltechAUTHORS:20170213-145705837

Related works

Describes
https://arxiv.org/abs/1611.01521 (URL)

Funding

NASA/JPL/Caltech
Alexander von Humboldt Foundation
Max Planck Institute für Astronomie
Cottrell Scholar of Research Corporation

Dates

Created
2017-02-13
Created from EPrint's datestamp field
Updated
2021-11-11
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC) , Physics Department