774 research outputs found
CO Observations of the Interacting Galaxy Pair NGC 5394/95
BIMA CO 1-0 observations are presented of the spiral galaxies NGC 5394 and
NGC 5395 that have undergone a recent, grazing encounter. In NGC 5394, 80% of
the CO emission detected by BIMA is concentrated in the central 800 pc (FWHM)
starburst region.In an encounter simulation that reproduces some of the main
features of this galaxy pair, a considerable amount of gas in NGC 5394 falls
into the central region early in the collision. The observed total gas
distribution in the disk of NGC 5394 is lopsided, with more HI, CO, and H-alpha
emission coming from the western or southwestern side. The innermost western
arm of NGC 5394 is seen in CO and H-alpha emission, but the eastern inner-disk
arm, which is very bright in the optical continuum, is not detected in CO or
H-alpha emission. From a comparison of the radio continuum, H-alpha, 60 micron,
and CO luminosities, we estimate that the average visual extinction of the
starburst is 3 - 4 mag and the conversion factor N(H2)/I(CO) in the starburst
is a factor of 3 - 4 below the standard value. Comparison of NGC 5394 with two
other systems previously studied suggests that in prograde grazing encounters a
central starburst may not develop until near the end of the ocular phase. Very
little of the CO emission from NGC 5395 found in previous single-dish
observations is detected by BIMA.Comment: AAS-Latex, v5.0, 45 pages including embedded .ps figures. AJ, in
pres
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