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Session 11 - LMC, Dwarf Galaxies.
Display session, Monday, January 15
North Banquet Hall, Convention Center
We present a study of the components of the interstellar medium (ISM) in NGC 185 and NGC 205, two dwarf elliptical companions of M31. These two galaxies provide a laboratory for investigating what determines the state of the ISM, and how star formation and the ISM affect each other, in an environment very different from that of our own spiral Galaxy. We have imaged the atomic gas in these two galaxies with observations of HI, using the VLA C and D configurations, at resolutions of about 60 pc and 1.3 km/s. ^12CO J=1-0 and 2-1 emission has been detected in several positions using the IRAM 30m telescope at resolutions comparable those of the HI data. We have also observed H\alpha emission in these two galaxies using the 1m telescope at Mount Laguna Observatory.
HI in NGC 185, and to a lesser extent in NGC 205, can be separated into broad (\sigma \approx13 km/s) and narrow (\sigma \approx3 km/s) components with different distributions and kinematics. Comparison with CO spectra shows that the variations in gas dispersion from place to place in the galaxies are mostly due to differing amounts of nonthermal or turbulent broadening in the ISM. The locations of quiescent and active regions in the galaxies are compared with the distributions of young massive stars and other probable sources of kinetic energy, to help study how energy moves through the ISM.
Program listing for Monday