Volume 488, Number 1, September II 2008
|Page(s)||L5 - L8|
|Published online||17 July 2008|
Letter to the Editor
Mechanical feedback in the molecular ISM of luminous IR galaxies
Kapteyn Astronomical Institute, PO Box 800, 9700 AV Groningen, The Netherlands e-mail: email@example.com
2 ASTRON, PO Box 2, 7990 AA Dwingeloo, The Netherlands
3 Astronomy Department, University of California, Berkeley, CA 94720, USA
Accepted: 4 July 2008
Aims. Molecular emission lines originating in the nuclei of luminous infra-red galaxies are used to determine the physical properties of the nuclear ISM in these systems.
Methods. A large observational database of molecular emission lines is compared with model predictions that include heating by UV and X-ray radiation, mechanical heating, and the effects of cosmic rays.
Results. The observed line ratios and model predictions imply a separation of the observed systems into three groups: XDRs, UV-dominated high-density ( cm-3) PDRs, and lower-density ( cm-3) PDRs that are dominated by mechanical feedback.
Conclusions. The division of the two types of PDRs follows naturally from the evolution of the star formation cycle of these sources, which evolves from deeply embedded young stars, resulting in high-density ( cm-3) PDRs, to a stage where the gas density has decreased ( cm-3) and mechanical feedback from supernova shocks dominates the heating budget.
Key words: ISM: molecules / galaxies: ISM / galaxies: starburst / galaxies: active / infrared: galaxies / radio lines: galaxies
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.