One of the exciting new results of the Herschel mission is the discovery of massive, high velocity (v virgul 1000 km/sec) molecular outflows in ultraluminous infrared galaxies (ULIRGs). These outflows, powered by stellar processes or by AGN, are so far, best traced by radiatively pumped far-IR OH transitions and are observed in numerous transitions as P-Cygni, absorption, or emission line profiles. Based on our modeling of the lines and continuum, the OH observations imply short gas depletion times, mass loss rates at least several times higher than the star formation rates, and appear strongest in AGN dominated ULIRGs. These mergers of gas-rich galaxies have been caught in the act of dispersing their star-forming molecular fuel as they evolve toward becoming massive, gas-poor ellipticals! Are these outflows driven by radio jets or radiation pressure due to a partially buried AGN or are compact super-starburst winds carving out a view to a previously hidden AGN? We and others have tuned Herschel PACS spectroscopic scans to one or more OH lines in surveys of infrared-bright galaxies to combine with modeling efforts to derive the parameters of these winds. However, in order to help understand the excitation and radiative effects producing these winds and thus to better ascertain the nature of the driving source(s), we propose to fill in the gaps and thus obtain full PACS spectral scans of two key outflow sources: Mrk 231, a broad absorption line (BAL) quasar, and NGC 6240, a close pair of X-ray luminous AGN. The PACS spectral resolution and sensitivity will enable unprecedented understanding of the outflow mass-loss rates, energetics, and the radiative environments to which their ISM is exposed, based on velocity-resolved line profiles of multiple excited level transitions of OH, H2O, CO, OH+, H2O+, and oth...er molecules. A key goal of this program is to provide foundations for the modeling and understanding of the now numerous Herschel OH outflow surveys of ULIRGs.
Publication
Far-infrared Line Spectra of Active Galaxies from the Herschel/PACS Spectrometer: The Complete Database . Fernández-Ontiveros Juan Antonio et al. . The Astrophysical Journal Supplement Series, Volume 226, Issue 2, article id. 19, 26 pp. (2016). . 226 . 10.3847\/0067-0049\/226\/2\/19 . 2016ApJS..226...19F , Measuring chemical abundances in AGN from infrared nebular lines: HII-CHI-MISTRY-IR for AGN . Pérez-Díaz Borja et al. . Astronomy and Astrophysics . null . null . 2022A&A...666A.115P , Importance of radiative pumping for the excitation of the H2O submillimeter lines in galaxies . González-Alfonso Eduardo et al. . Astronomy and Astrophysics . null . null . 2022A&A...666L...3G ,
Instrument
PACS_PacsRangeSpec_point
Temporal Coverage
2012-09-25T04:36:26Z/2012-10-16T14:49:29Z
Version
SPG v14.2.0
Mission Description
Herschel was launched on 14 May 2009! It is the fourth 'cornerstone' mission in the ESA science programme. With a 3.5 m Cassegrain telescope it is the largest space telescope ever launched. It is performing photometry and spectroscopy in approximately the 55-671 µm range, bridging the gap between earlier infrared space missions and groundbased facilities.
European Space Agency, 2013, Far-Infrared Full Spectroscopic Signatures Of The Massive Molecular Outflows In The Openparucloseparlirgs Mrk 231 And Ngc 6240, SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-2mjrj5n
