| Issue |
EAS Publications Series
Volume 31, 2008
Far-Infrared Workshop 2007
|
|
|---|---|---|
| Page(s) | 85 - 88 | |
| DOI | https://doi.org/10.1051/eas:0831017 | |
| Published online | 04 October 2008 | |
C. Kramer, S. Aalto and R. Simon (eds)
EAS Publications Series, 31 (2008) 85-88
Molecular line probes of activity in galaxies
1
Observatorio de Madrid, OAN, Alfonso XII, 3, 28014-Madrid, Spain
2
CfA, SMA project, 60 Garden Street, MS 78 Cambridge, MA 02138, USA
Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.
Abstract
The use of specific tracers of the dense molecular gas phase can help to explore the feedback of activity on the interstellar medium (ISM) in galaxies. This information is a key to any quantitative assessment of the efficiency of the star formation process in galaxies. We present the results of a survey devoted to probe the feedback of activity through the study of the excitation and chemistry of the dense molecular gas in a sample of local universe starbursts and active galactic nuclei (AGNs). Our sample includes also 17 luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs). From the analysis of the LIRGs/ULIRGs subsample, published in Graciá-Carpio et al. (2007), we find the first clear observational evidence that the star formation efficiency of the dense gas, measured by the LFIR/LHCN ratio, is significantly higher in LIRGs and ULIRGs than in normal galaxies. Mounting evidence of overabundant HCN in active environments would even reinforce the reported trend, pointing to a significant turn upward in the Kennicutt-Schmidt law around LFIR = 1011L๏. This result has major implications for the use of HCN as a tracer of the dense gas in local and high-redshift luminous infrared galaxies.
© EAS, EDP Sciences, 2008