Powerful radio galaxies have played a central role in our understanding of active galaxies over the past five decades. Cygnus-A, the brightest and most nearby FR-II source, has been a Rosetta Stone in this study.It appears to have the outward characteristics of a normal radio galaxybut it.s proximity allows us to identify the more subtle properties ofan obscured quasar. The energy provided by this very active galaxyis sufficient to launch the energetic jets we observe but the transportof the energy to the hotspots is poorly constrained and understood.The growing realisation that AGN directly affect their host galaxythrough a direct feedback mechanism throughout the lifetime of thegalaxy makes it especially important for the most nearby obscured quasar to be observed with the widest possible spectral coverage.We propose to use Herschel to reveal the heating of the central region and the energetics of the hotspots. We request observations of theatomic cooling lines OI, OIII and CII that will allow us to compare theenergetics of the ISM in Cygnus A with other local and more distantgalaxies.
Publication
Infrared colours and spectral energy distributions of hard X-ray selected obscured and Compton-thick active galactic nuclei | Kilerci Eser Ece et al. | Monthly Notices of the Royal Astronomical Society | null | null | 2020MNRAS.494.5793K |
L.CO/LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive | Kamenetzky J. et al. | The Astrophysical Journal Volume 829 Issue 2 article id. 93 16 pp. (2016). | 829 | 10.3847\\/0004-637X\\/829\\/2\\/93 | 2016ApJ...829...93K | http://adsabs.harvard.edu/abs/2016ApJ...829...93K
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, edge et al., 2012, 'A definitive Herschel study of the most powerful local radio galaxy - Cygnus A', SPG v14.2.0, European Space Agency, https://doi.org/10.5270/esa-jxwcjqk
