Molecular properties of (U)LIRGs: CO, HCN, HNC and HCO+
Abstract
The observed molecular properties of a sample of FIR-luminous and OH megamaser (OH-MM) galaxies have been investigated. The ratio of high and low-density tracer lines is found to be determined by the progression of the star formation in the system. The HCO+/HCN and HCO+/HNC line ratios are good proxies for the density of the gas, and PDR and XDR sources can be distinguished using the HNC/HCN line ratio. The properties of the OH-MM sources in the sample can be explained by PDR chemistry in gas with densities higher than 105.5cm−3, confirming the classical OH-MM model of IR pumped amplification with (variable) low gains.
- Publication:
-
Astrophysical Masers and their Environments
- Pub Date:
- March 2007
- DOI:
- 10.1017/S1743921307013609
- arXiv:
- arXiv:0709.3423
- Bibcode:
- 2007IAUS..242..462L
- Keywords:
-
- galaxies: nuclei;
- galaxies: ISM;
- galaxies: active;
- galaxies: starburst;
- ISM: molecules;
- ISM: evolution;
- radio lines: ISM;
- Astrophysics
- E-Print:
- 5 pages, 2 figures, to appear in: IAU Symposium 242 Astrophysical Masers and their Environments