Molecular Gas in Violent Phases of GalaxyEvolution

摘要

One of the most surprising results obtained with the Spitzer space telescope was the discovery of powerful mid-IR H_2 line emission from a significant number of sources that are in active phases of galaxy evolution, in which star formation seems strongly suppressed. The underlying physics may be a key ingredient to describe the buildup of baryonic mass in galaxies and their evolution. We present here two multiwavelength studies of an interacting galaxy system, Stephan's Quintet, and an AGN host radio galaxy, 3C326, which suggest that the H_2 line emission heralds the dissipation of kinetic energy in a multiphase medium. The results provide new insight on the energetics of galaxy formation.