Shock Excited Molecules in NGC 1266: ULIRG Conditions at the Center of a Bulge-dominated Galaxy

December 2013 • 2013ApJ...779L..19P

Authors • Pellegrini, E. W. • Smith, J. D. • Wolfire, M. G. • Draine, B. T. • Crocker, A. F. • Croxall, K. V. • van der Werf, P. • Dale, D. A. • Rigopoulou, D. • Wilson, C. D. • Schinnerer, E. • Groves, B. A. • Kreckel, K. • Sandstrom, K. M. • Armus, L. • Calzetti, D. • Murphy, E. J. • Walter, F. • Koda, J. • Bayet, E. • Beirao, P. • Bolatto, A. D. • Bradford, M. • Brinks, E. • Hunt, L. • Kennicutt, R. • Knapen, J. H. • Leroy, A. K. • Rosolowsky, E. • Vigroux, L. • Hopwood, R. H. B.

Abstract • We investigate the far infrared (IR) spectrum of NGC 1266, a S0 galaxy that contains a massive reservoir of highly excited molecular gas. Using the Herschel Fourier Transform Spectrometer, we detect the 12CO ladder up to J = (13-12), [C I] and [N II] lines, and also strong water lines more characteristic of UltraLuminous IR Galaxies (ULIRGs). The 12CO line emission is modeled with a combination of a low-velocity C-shock and a photodissociation region. Shocks are required to produce the H2O and most of the high-J CO emission. Despite having an IR luminosity 30 times less than a typical ULIRG, the spectral characteristics and physical conditions of the interstellar medium of NGC 1266 closely resemble those of ULIRGs, which often harbor strong shocks and large-scale outflows.


IPAC Authors


Lee Armus

Senior Scientist