BASS XXXI: Outflow scaling relations in low redshift X-ray AGN host galaxies with MUSE

Abstract

Ionised gas kinematics provide crucial evidence of the impact that active galactic nuclei (AGN) have in regulating star formation in their host galaxies. Although the presence of outflows in AGN host galaxies has been firmly established, the calculation of outflow properties such as mass outflow rates and kinetic energy remains challenging. We present the [$\rm O\, {\rm \small III}$]λ5007 ionised gas outflow properties of 22 z<0.1 X-ray AGN, derived from the BAT AGN Spectroscopic Survey using MUSE/VLT. With an average spatial resolution of 1″(0.1–1.2 kpc), the observations resolve the ionised gas clouds down to sub-kiloparsec scales. Resolved maps show that the [$\rm O\, {\rm \small III}$] velocity dispersion is, on average, higher in regions ionised by the AGN, compared to star formation. We calculate the instantaneous outflow rates in individual MUSE spaxels by constructing resolved mass outflow rate maps, incorporating variable outflow density and velocity. We compare the instantaneous values with time-averaged outflow rates by placing mock fibres and slits on the MUSE field-of-view, a method often used in the literature. The instantaneous outflow rates (0.2–275 M⊙ yr−1) tend to be 2 orders of magnitude higher than the time-averaged outflow rates (0.001–40 M⊙ yr−1). The outflow rates correlate with the AGN bolometric luminosity (Lbol ∼ 1042.71–1045.62 erg/s) but we find no correlations with black hole mass (106.1–108.9 M⊙), Eddington ratio (0.002–1.1) and radio luminosity (1021–1026 W/Hz). We find the median coupling between the kinetic energy and Lbol to be 1 per cent, consistent with the theoretical predictions for an AGN-driven outflow.

Ionized Outflows in Nearby Quasars Are Poorly Coupled to Their Host Galaxies

“…While there has been much tantalizing evidence of multiphase outflows in AGNs reported in the literature (e.g., Cicone et al 2014;Feruglio et al 2015;Karouzos et al 2016;Morganti 2017;Cicone et al 2018;Fluetsch et al 2019;Veilleux et al 2020), we have a poor understanding of how efficiently the outflows actually affect the host galaxy (e.g., Harrison et al 2018;Kakkad et al 2022). The naive expectation that AGN feedback expels and depletes the cold gas reservoir is certainly not borne out by much of the evidence.…”

“…Theoretical arguments abound concerning the need for negative AGN feedback to solve a suite of otherwise intractable problems in galaxy evolution. Theoretical and numerical works argue that outflows with kinetic powers of a few percent of the energy radiated by the AGN (  E L 0.05 0.5 Shimizu et al 2019;Kakkad et al 2022). A major source of uncertainty pertains to the degree to which outflows actually couple to the cold gas reservoir of the host galaxy.…”

BASS XXXVII: The Role of Radiative Feedback in the Growth and Obscuration Properties of Nearby Supermassive Black Holes

“…This includes data in the radio (Baek et al 2019;Smith et al 2020), millimeter (Koss et al 2021;Kawamuro et al 2022), infrared (Ichikawa et al 2017;Lamperti et al 2017;Ichikawa et al 2019;den Brok et al 2022;Ricci et al 2022), optical (Koss et al 2017), and X-rays (Ricci et al 2017b). This has led to a number of follow-up studies comparing the X-ray continuum and optical properties of AGNs with their accretion rates (Oh et al 2017;Trakhtenbrot et al 2017;Ricci et al 2018;Rojas et al 2020;Kakkad et al 2022). The first BASS data release (Koss et al 2017) reported black hole masses for 473 AGNs, and X-ray properties for all 838 AGNs from the flux-limited Swift/BAT 70 month sample (Ricci et al 2017b).…”

Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies. IV. The Effects of Different Density Estimates on the Ionized Gas Masses and Outflow Rates

“…Significant effort is being devoted to understanding the physics of AGN-driven outflows and measuring their energetic impact (e.g., Fischer et al 2018;Baron & Netzer 2019a, 2019bFörster Schreiber et al 2019;Mingozzi et al 2019;Davies et al 2020b;Wylezalek et al 2020;Avery et al 2021;Fluetsch et al 2021;Lamperti et al 2021;Luo et al 2021;Negus et al 2021;Ruschel-Dutra et al 2021;Speranza et al 2021;Vayner et al 2021;Bianchin et al 2022;Deconto-Machado et al 2022;Kakkad et al 2022). However, outflows are inhomogeneous, with a large range of densities and geometries, such that the derived gas masses and outflow rates depend strongly on how the gas densities are estimated.…”