CLEARING OUT A GALAXY

By K. Zubovas, A. King. 2012

139 citations recorded by the source corpus.

It is widely suspected that active galactic nucleus (AGN) activity ultimately sweeps galaxies clear of their gas. We work out the observable properties required to achieve this. Large-scale AGN-driven outflows should have kinetic luminosities ∼η LEdd/2 ∼ 0.05 LEdd and momentum rates ∼20 LEdd/c, where  LEdd is the Eddington luminosity of the central black hole and η ∼ 0.1 its radiative accretion efficiency. This creates an expanding two-phase medium in which molecular species coexist with hot gas, which can persist after the central AGN has switched off. This picture predicts outflow velocities ∼1000–1500 km s−1 and mass outflow rates up to 4000 M☉ yr−1 on kpc scales, fixed mainly by the host galaxy velocity dispersion (or equivalently black hole mass). All these features agree with those of outflows observed in galaxies such as Mrk231. This strongly suggests that AGN activity is what sweeps galaxies clear of their gas on a dynamical timescale and makes them red and dead. We suggest future observational tests of this picture.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/e5fefb8e3bcfd64409beb79e58f38f4040ce76aa

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In Astronomy and Astrophysics

1. D. M. Alexander
2. P. Hopkins
3. L. Hernquist
4. R. Maiolino
5. R. Genzel
6. P. V. van Dokkum
7. T. Naab
8. A. Dekel

In Electrical and Electronic Engineering

1. F. Mannucci
2. R. Maiolino
3. Jenny E. Greene
4. N. Zakamska
5. T. Naab
6. G. Cresci
7. S. Chapman
8. F. Walter

In Instrumentation

1. P. Hopkins
2. D. M. Alexander
3. L. Hernquist
4. P. V. van Dokkum
5. R. Genzel
6. A. Dekel
7. T. Naab
8. S. Wuyts

Citations in the corpus

• Observations of feedback from radio-quiet quasars – II. Kinematics of ionized gas nebulae (2013, background): “Our derived values of outflow velocities and mass outflow rates are not dissimilar from those predicted by models of feedback necessary to regulate the black hole/galaxy correlations (King 2010; Zubovas & King 2012).”
• EVIDENCE FOR WIDE-SPREAD ACTIVE GALACTIC NUCLEUS-DRIVEN OUTFLOWS IN THE MOST MASSIVE z ∼ 1–2 STAR-FORMING GALAXIES (2014, background): “Observability of the outflow may be extended further into periods of unobservable direct AGN radiation if the ionizing agent is a combination of photoionization and of delayed shocks set by the AGN outbursts, as discussed in Section 3.2 (e.g., Zubovas & King 2012; Gabor & Bournaud 2014).”
• Unification of X-ray winds in Seyfert galaxies: from ultra-fast outflows to warm absorbers (2012, background): “…all of them rely on a two step process in which an initial ∼sub-pc scale fast (vout > 1, 000 km s −1) AGN accretion disc outflow perturbs/shocks the interstellar medium, sweeping it up on its way and then decelerates/cools (e.g. King 2010a; Zubovas & King 2012; Faucher-Giguère & Quataert 2012).”
• Energetic galaxy-wide outflows in high-redshift ultraluminous infrared galaxies hosting AGN activity (2012, background): “Many of the most successful models of galaxy formation require energetic outflows over galaxy scales (i.e.≈1–10 kpc) to reproduce properties of local massive galaxies (e.g., black-hole spheroid mass relationship; the bright-end of the galaxy luminosityfunction; e.g., Silk & Rees 1998; Springel et al”
• Observations of feedback from radio-quiet quasars - I. Extents and morphologies of ionized gas nebulae (2013, background): “The radiation pressure of the quasar (Murray et al. 1995; Proga et al. 2000) drives a low-density high-temperature wind (Faucher-Giguère & Quataert 2012; Zubovas & King 2012) which slams into dense clumps in the host galaxy, resulting in shocked emission.”
• Evidence of strong quasar feedback in the early Universe (2012, background): “…the bulk of their gas, therefore quenching star formation (Silk & Rees 1998; Granato et al. 2004; Di Matteo et al. 2005; Springel et al. 2005; Croton et al. 2006; Narayanan et al. 2008; Hopkins et al. 2008; Fabian et al. 2009; King 2010; King et al. 2011; Hopkins & Elvis 2010; Zubovas & King 2012).”
• Ionised outflows in z $\sim$ 2.4 quasar host galaxies (2015, methodology): “Theoretical models (e.g Zubovas & King 2012, Faucher-Giguère & Quataert 2012) predict tight relations between these quantities and the AGN bolometric luminosity, LAGN.”