Herschel-PACS spectroscopic diagnostics of local ULIRGs: Conditions and kinematics in Markarian?231

摘要

In this first paper on the results of our Herschel PACSsurvey of local ultra luminous infrared galaxies (ULIRGs), as part ofour SHINING survey of local galaxies, we present far-infraredspectroscopy of Mrk231, the most luminous of the local ULIRGs,and a type1 broad absorption line AGN. For the first time in aULIRG, all observed far-infrared fine-structure lines in the PACS rangewere detected and all were found to be deficient relative tothe far infrared luminosity by 1-2orders of magnitude comparedwith lower luminosity galaxies. The deficits are similar to those forthe mid-infrared lines, with the most deficient lines showing highionization potentials. Aged starbursts may account for part of thedeficits, but partial covering of the highest excitation AGN poweredregions may explain the remaining line deficits. A massive molecularoutflow, discovered in OH and 18OH, showing outflow velocities out to at least 1400kms-1,is a unique signature of the clearing out of the molecular disk thatformed by dissipative collapse during the merger. The outflow ischaracterized by extremely high ratios of 18O/16O suggestive of interstellar medium processing by advanced starbursts.Key words: infrared: galaxies - galaxies: ISM - quasars: absorption lines - galaxies: individual: Mrk 231