Details on the event


Coffee talks

Friday 27/11/2020 @ 11:30, On-line -

Francesco Santoro (MPIA, Heidelberg), "AGN-driven outflows: density matters!"

Active galactic nuclei (AGN) feedback operated by the expansion of radio jets can play a crucial role in driving gaseous outflows on galaxy scales. Galaxies hosting young radio AGN, whose jets are in the first phases of expansion through the surrounding interstellar medium (ISM), are the ideal targets to probe the energetic significance of this mechanism. In this talk I will discuss the warm ionised gas outflows found in a sample of nine young radio sources from the 2Jy sample using X-shooter spectroscopy and Hubble Space Telescope (HST) imaging data. I find that the warm outflows have similar radial extents (~0.06-2 kpc) as radio sources, consistent with the idea that 'jet mode' AGN feedback is the dominant driver of the outflows detected in young radio galaxies. Exploiting the broad spectral coverage of the X-shooter data, I have used the ratios of trans-auroral emission lines of [SII] and [OII] to estimate the electron densities, finding that most of the outflows have quite high gas densities which we speculate could be the result of compression by jet-induced shocks. I will show how these densities tend to lower the estimates of the kinetic powers of the warm outflows and the overall AGN feedback efficiency. Finally, by comparing the outflow properties of the young radio AGN with the ones of outflows collected from the literature, I will show how the 'jet mode’ feedback can be as efficient as the ‘quasar mode’ feedback in driving outflows.