Luminous Infrared Galaxies in a Merging Sequence

K. Y. Lo, Chorng-Yuan Hwang, Siow-Wang Lee, Ting-Hui Lee,
Wei-Hao Wang & Mao-Chang Liang & Bau-Ching Hsieh (ASIAA)
and
Robert Gruendl & Yu Gao (Illinois)

Luminous infrared galaxies (LIRGs) are galaxies which emit a large fraction of their bolometric luminosity in the infrared. They typically have total infrared luminosities, Lir > 10^11 solar luminosity. Many LIRGs are interacting systems and contain large amount of molecular gas.

A common interpretation of the exceedingly high infrared luminosity in interacting LIRGs is that these galaxies are currently experiencing starburst phenonmena triggered by the interactions. The detailed processes of how and when during an interaction starbursts begin are, however, unclear. Merging sequence predicted by numerical simulations has not been proven observationally.

We have begun a multiwavelength study of a sample of about 15 interacting LIRGs. Unlike previous works, we have included galaxies pairs at the early (presumably pre-starburst), intermediate and late stage of interaction. This sequencing is essential for locating the onset of starbursts and for constraining the initial conditions leading to starbursts. Such knowledge are important for the understanding of the actual physical processes of starbursts. Our study will also follow the subsequent development of mergers, allowing quantitative measurements, as a function of merger stage, of such parameters as molecular surface densities, the amount of concentration of gas towards the galaxies nuclei, the location of star formation and the star formation efficiencies.

Note: All data in these pages must not be reproduced in any form without permission.

Master List

Progress Summary

A Merger Sequence

Bibliography

last edit: 1 Dec 1998