Shock Excited Molecules in NGC 1266: ULIRG conditions at the center of a Bulge Dominated Galaxy

摘要

We investigate the far infrared spectrum of NGC 1266, a S0 galaxy thatcontains a massive reservoir of highly excited molecular gas. Using theSPIRE-FTS, we detect the $^{12}$CO ladder up to J=(13-12), [C I] and [N II]lines, and also strong water lines more characteristic of UltraLuminous IRGalaxies (ULIRGs). The 12CO line emission is modeled with a combination of alow-velocity C-shock and a PDR. Shocks are required to produce the H2O and mostof the high-J 12CO emission. Despite having an infrared luminosity thirty timesless than a typical ULIRG, the spectral characteristics and physical conditionsof the ISM of NGC 1266 closely resemble those of ULIRGs, which often harborstrong shocks and large-scale outflows.