| Description |
This proposal is aimed at obtaining PACS spectroscopic data of 10 bright (5 type-1 and 5 type-2) Seyfert nuclei for six atomic fine-structure lines (OIII52um, OI63um, OIII88um, NII122um, OI145um and CII157um) and two molecular lines (CO J=18-17 and OH 119um). It will complete the coverage of the same ionic lines of another 11 Seyfert galaxies, already observed or reserved, by targeting the OIII52um line only. All targets were selected based on their optical classification and on the strength of their OIV25.9um fine-structure-line emission, proportional to their AGN bolometric luminosity. The proposed targets are among the brightest accretion-powered sources in the local Universe. The two OIII lines, together with the OIV line measured by Spitzer, will be used for the determination of their narrow-line-region gas density. The FIR spectroscopic tracers, combined with the MIR ones obtained with Spitzer, will enable us to classify and model the various levels of non-thermal and starburst activity in local bright Seyferts. The mid-to far-IR line ratio diagnostic diagrams that we will construct will be essential for the future interpretation of spectroscopic surveys at long wavelengths with ALMA and SPICA. The high spectral resolution of PACS will allow us to further study the dynamics of the nuclear gas, in combination with lines spectrally resolved by Spitzer IRS. The range spectroscopy with PACS has been optimized to allow the detection of 6 fine structure lines, 1 CO line, 1 OH doublet in a total time of 18.0 hours. |
