The MURALES survey

Abstract

We analyze VLT/MUSE observations of 37 radio galaxies from the Third Cambridge catalogue (3C) with redshift < 0.3 searching for nuclear outflows of ionized gas. These observations are part of the MURALES project (a MUse RAdio Loud Emission line Snapshot survey), whose main goal is to explore the feedback process in the most powerful radio-loud AGN. We applied a nonparametric analysis to the [O III] λ5007 emission line, whose asymmetries and high-velocity wings reveal signatures of outflows. We find evidence of nuclear outflows in 21 sources, with velocities between ∼400 and 1000 km s−1, outflowing masses of ∼105 − 107 M⊙, and a kinetic energy in the range ∼1053 − 1056 erg. In addition, evidence for extended outflows is found in the 2D gas velocity maps of 13 sources of the subclasses of high-excitation (HEG) and broad-line (BLO) radio galaxies, with sizes between 0.4 and 20 kpc. We estimate a mass outflow rate in the range 0.4–30 M⊙ yr−1 and an energy deposition rate of Ėkin ∼ 1042 − 1045 erg s−1. Comparing the jet power, the nuclear luminosity of the active galactic nucleus, and the outflow kinetic energy rate, we find that outflows of HEGs and BLOs are likely radiatively powered, while jets likely only play a dominant role in galaxies with low excitation. The low loading factors we measured suggest that these outflows are driven by momentum and not by energy. Based on the gas masses, velocities, and energetics involved, we conclude that the observed ionized outflows have a limited effect on the gas content or the star formation in the host. In order to obtain a complete view of the feedback process, observations exploring the complex multiphase structure of outflows are required.

Blandford-Znajek jets in galaxy formation simulations: exploring the diversity of outflows produced by spin-driven AGN jets in Seyfert galaxies

“…• In terms of mass outflow rates and large-scale kinetic powers in warm ionised gas, our simulations are comparable to recent observations of Seyfert galaxies that host black holes of similar masses and bolometric luminosities (Venturi et al 2021;Ruschel-Dutra et al 2021). Additionally, line-of-sight (LoS) velocity maps of this warm gas component indicate that our jet-driven outflows have high velocities (up to ∼ 500 km s −1 ) that are comparable to those found in Venturi et al (2021); Speranza et al (2021); Jarvis et al (2019).…”

“…Across these simulations we find a wide range of outflow velocities that encompass those found in observational studies such as Venturi et al (2021); Speranza et al (2021); Jarvis et al (2019) and in simulations such as those of misaligned jets in Mukherjee et al (2018) and of clusters in Ehlert et al (2021).…”

“…Recent observations indicate that it is not just high power jets and those found in massive systems that are able to significantly impact their host galaxy. These observations suggest that ionised outflows may be more prevalent and have a greater effect on the nuclear kinematics in low-excitation galaxies and in cases where the radio emission is compact (Speranza et al 2021;Molyneux et al 2019;Harrison et al 2015;Holt et al 2008;Das et al 2006).…”

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.…”

“…This choice of density profile is physically motivated by the observation that the [O III]/Hβ ratio, which is a strong function of the ionization parameter, is approximately constant across the NLR for most galaxies in the sample (see also Stern et al 2014;Wang et al 2022). An underlying assumption of this method is that the total ionized gas mass is traced out equally well by the [O III] emission at all radial distances.…”