IAU Symposium Abstract S186-081P
CO Observations of Luminous Infrared Galaxies in a Merger Sequence
Yu Gao1,2 and Philip Solomon1
1 Astronomy Program, State Univ. of New York at Stony Brook $<email@example.com>
2 Dept. of Astronomy, Univ. of Illinois at Urbana-Champaign (current address) <firstname.lastname@example.org>
In order to determine the relationship
between the infrared and molecular gas properties and
the galaxy-galaxy interactions,
we study luminous infrared galaxy mergers (LIGMs) in the
intermediate merging process.
We have conducted new CO observations of LIGMs and
found a correlation between the CO luminosity and the projected
separation of merger nuclei in a sample of >50 LIGMs,
which suggests that the molecular content is decreasing as
merging advances. The correlation
is better established with a sample of approximately 40 LIGMs excluding
ultraluminous ones, which resembles more to a volume-limited,
statistically complete sample of LIGMs in the local universe.
One possible interpretation is
that the molecular gas content of LIGMs is being rapidly depleted
due to the merger-induced starbursts when merging progresses to
more advanced stage.
As a follow-up study, high resolution CO imaging has been mapped in
10 LIGMs selected to represent a merger sequence. Detailed results
are discussed in an oral contribution by Gao et al.