High-Resolution Sub/millimeter Observations of Mergers and Luminous
  Galaxy Nuclei
  I present recent high-resolution submillimeter and millimeter observations of
molecular gas and dust in some mergers, luminous galaxy nuclei, and possible
mergers. Such observations tell us the behavior and properties of interstellar
medium in merger nuclei. For example, the gas sometimes makes a mini disk
around the remnant nucleus, feeds starburst and/or a massive black hole there,
hides such a power source(s) by enveloping it, and is blown out by the embedded
power source. Even when the power source is completely enveloped and hidden we
can still constrain its physical parameters and nature from high-resolution
(sub)millimeter observations. The observables include gas motion such as
rotation (hence dynamical mass) and inflow/outflow, luminosity and luminosity
density of the embedded nucleus, and mass, temperature, density, chemical
composition, and (sometimes unusual) excitation conditions of gas.
