AGN wind scaling relations and the co-evolution of black holes and galaxies

Abstract

Context. Feedback from accreting supermassive black holes is often identified as the main mechanism responsible for regulating star-formation in AGN host galaxies. However, the relationships between AGN activity, radiation, winds, and star-formation are complex and still far from being understood. Aims. We study scaling relations between AGN properties, host galaxy properties and AGN winds. We then evaluate the wind mean impact on the global star-formation history, taking into account the short AGN duty cycle with respect to that of star-formation. Methods. We first collect AGN wind observations for 94 AGN with detected massive winds at sub-pc to kpc spatial scales. We then fold AGN wind scaling relations with AGN luminosity functions, to evaluate the average AGN wind mass-loading factor as a function of cosmic time. Results. We find strong correlations between the AGN molecular and ionised wind mass outflow rates and the AGN bolometric luminosity. The power law scaling is steeper for ionised winds (slope 1.29±0.38) than for molecular winds (0.76±0.06), meaning that the two rates converge at high bolometric luminosities. The molecular gas depletion timescale and the molecular gas fraction of galaxies hosting powerful AGN driven winds are 3-10 times shorter and smaller than those of main-sequence galaxies with similar star-formation rate, stellar mass and redshift. These findings suggest that, at high AGN bolometric luminosity, the reduced molecular gas fraction may be due to the destruction of molecules by the wind, leading to a larger fraction of gas in the atomic ionised phase. The AGN wind mass-loading factor η =ṀOF /SFR is systematically higher than that of starburst driven winds. Conclusions. Our analysis shows that AGN winds are, on average, powerful enough to clean galaxies from their molecular gas only in massive systems at z < ∼ 2, i.e. a strong form of co-evolution between SMBHs and galaxies appears to break down for the least massive galaxies.

Evidence for a radiatively driven disc-wind in PDS 456?

“…Thus the observed velocities can be easily reproduced within this framework. Note that a comparable positive cor-relation between the outflow velocity and luminosity has been recently found by Gofford et al (2015) and Fiore et al (2017), the latter from collating a sample of known AGN outflows.…”

Quasar-mode Feedback in Nearby Type 1 Quasars: Ubiquitous Kiloparsec-scale Outflows and Correlations with Black Hole Properties

“…Previous studies have found that velocities of kpc-scale outflows in AGN reach the highest velocities (∼1000 km s −1 or higher) only at quasar-like luminosities (∼10 45 erg s −1 ), and that there is a correlation between outflow velocity and AGN luminosity (Sturm et al 2011;Spoon et al 2013;Veilleux et al 2013a;Rupke & Veilleux 2013b;Harrison et al 2014;Cicone et al 2014;Stone et al 2016;González-Alfonso et al 2017;Sun et al 2017;Fiore et al 2017). Figure 17 shows how velocity depends on AGN luminosity in IFS observations of ionized and neutral gas velocities in nearby Type 1 and 2 quasars and luminous starbursts (Rupke & Veilleux 2013b and this study).…”

“…Previous studies have focused on how quasar-mode outflows depend on host or AGN properties (e.g., Sturm et al 2011;Veilleux et al 2013a;Spoon et al 2013;Rupke & Veilleux 2013b;Harrison et al 2014;Cicone et al 2014;McElroy et al 2015;Stone et al 2016;Sun et al 2017;Fiore et al 2017). Since this sample of nearby luminous AGN has substantial ancillary data, and thus useful constraints on the central black hole (Table 1), this paper focuses on the dependence of outflow properties on black hole properties.…”

“…The properties of quasar-mode AGN outflows (velocity, mass outflow rate) correlate with bolometric AGN luminosity (Sturm et al 2011;Spoon et al 2013;Veilleux et al 2013a;Rupke & Veilleux 2013b;Cicone et al 2014;Stone et al 2016;González-Alfonso et al 2017;Sun et al 2017;Fiore et al 2017). The gas depletion timescales are short in the most luminous AGN, suggesting that feedback is most effective in these systems (Cicone et al 2014;González-Alfonso et al 2017).…”

NuSTAR View of the Black Hole Wind in the Galaxy Merger IRAS F11119+3257

“…Galactic winds driven by the central active galactic nucleus (AGN) and/or the surrounding starburst have been invoked to play a fundamental role in this phase, quenching the growth of both the SMBH and stellar spheroidal component, and possibly explaining the tight SMBH-spheroid mass relations (e.g., Silk & Rees 1998;King 2003;King & Pounds 2003;Gaspari & Saḑowski 2017). Finding observational evidence of such feedback mechanism(s) is of crucial importance to understand galaxy and SMBH evolution (e.g., Fiore et al 2017).…”