|Diffuse Dust Emission from Black Hole-driven Outflows in Halo-centered Massive Elliptical Galaxies
|Dust grains ejected into the hot interstellar gas in group-centered elliptical (E) galaxies are destroyed by ion-grain collisions, but during their short lifetime (10 Myrs) the grains emit sufficiently in the far infrared (FIR) to be easily observable. Remarkably, against this background emission, observations with Spitzer discovered many E galaxies with much stronger and spatially extended FIR emission from colder grains 5-10 kpc distant from the galaxy cores. Extended excess cold dust emission is interpreted as evidence of recent feedback-generated AGN energy outbursts in these galaxies, visible only in the FIR, from buoyant gaseous outflows from the galaxy cores. With Spitzer a quasi-radial plume of AGN-heated gas is resolved in only one galaxy, but marginally resolved in others. We request Herschel observations of a small sample of these E galaxies to confirm the existence of excess, spatially extended dust and to possibly spatially resolve more quasi-radial buoyant dusty gaseous plumes. Based on a detailed analysis of Spitzer data, our sample for Herschel is chosen to maximize the likelihood of discovering new FIR evidence of post-feedback events from massive galaxy-centered black holes.
|Spectral Energy Distribution Mapping of Two Elliptical Galaxies on Sub-kpc Scales . Amblard A. et al. . The Astrophysical Journal, Volume 834, Issue 1, article id. 20, 14 pp. (2017). . 834 . 10.3847/1538-4357/834/1/20 . 2017ApJ...834...20A ,
|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.
|Publisher And Registrant
|European Space Agency
|European Space Agency, 2013, OT2_ptemi_4, SPG v14.2.0. https://doi.org/10.5270/esa-pekywgk