TY - JOUR
T1 - The spatially resolved [C II] Cooling line deficit in galaxies
AU - Smith, J. D T
AU - Croxall, Kevin
AU - Draine, Bruce
AU - Looze, Ilse De
AU - Sandstrom, Karin
AU - Armus, Lee
AU - Beirão, Pedro
AU - Bolatto, Alberto
AU - Boquien, Mederic
AU - Brandl, Bernhard
AU - Crocker, Alison
AU - Dale, Daniel A.
AU - Galametz, Maud
AU - Groves, Brent
AU - Helou, George
AU - Herrera-Camus, Rodrigo
AU - Hunt, Leslie
AU - Kennicutt, Robert
AU - Walter, Fabian
AU - Wolfire, Mark
PY - 2017/1/1
Y1 - 2017/1/1
N2 - 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 vIv (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 ΣSFR. The tightness of this correlation suggests that an approximate 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.
AB - 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 vIv (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 ΣSFR. The tightness of this correlation suggests that an approximate 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.
KW - dust, extinction
KW - galaxies: ISM
KW - infrared: galaxies
KW - techniques: spectroscopic
UR - http://www.scopus.com/inward/record.url?scp=85010028177&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:2bea7b27-4b7e-45cf-a0cf-f093c834ac39
U2 - 10.3847/1538-4357/834/1/5
DO - 10.3847/1538-4357/834/1/5
M3 - Article
AN - SCOPUS:85010028177
SN - 0004-637X
VL - 834
JO - The Astrophysical Journal: an international review of astronomy and astronomical physics
JF - The Astrophysical Journal: an international review of astronomy and astronomical physics
IS - 1
M1 - 5
ER -