Molecular flows in contemporary active galaxies and the efficacy of radio-mechanical feedback

Abstract

Molecular gas flows are analyzed in 14 cluster galaxies (BCGs) centered in cooling hot atmospheres. The BCGs contain $10^{9}-10^{11}~\rm M_\odot$ of molecular gas, much of which is being moved by radio jets and lobes. The molecular flows and radio jet powers are compared to molecular outflows in 45 active galaxies within z < 0.2. We seek to understand the relative efficacy of radio, quasar, and starburst feedback over a range of active galaxy types. Molecular flows powered by radio feedback in BCGs are ∼10–1000 times larger in extent compared to contemporary galaxies hosting quasar nuclei and starbursts. Radio feedback yields lower flow velocities but higher momenta compared to quasar nuclei, as the molecular gas flows in BCGs are usually ∼10–100 times more massive. The product of the molecular gas mass and lifting altitude divided by the AGN or starburst power — a parameter referred to as the lifting factor—exceeds starbursts and quasar nuclei by two to three orders of magnitude, respectively. When active, radio feedback is generally more effective at lifting gas in galaxies compared to quasars and starburst winds. The kinetic energy flux of molecular clouds generally lies below and often substantially below a few percent of the driving power. We find tentatively that star formation is suppressed in BCGs relative to other active galaxies, perhaps because these systems rarely form molecular disks that are more impervious to feedback and are better able to promote star formation.

Radio jet–ISM interaction and positive radio-mechanical feedback in Abell 1795

“…The star formation depletion time-scales are much longer than the age of the stellar population and the radio lobes. Ho we ver, most of the molecular gas in Abell 1795 is flowing at a rate of ∼ 54 M yr −1 (Tamhane et al 2022 ). If the gas is inflowing, it can fuel a starburst in the centre, although it is unlikely that the molecular gas filaments are gas inflows (Russell et al 2017 ).…”

The Role of Active Galactic Nucleus Winds in Galaxy Formation: Connecting AGN Outflows at Low Redshifts to the Formation/Evolution of Their Host Galaxies

“…It seems now clear that outflows (OFs) are ubiquitous in active galactic nuclei (AGN; Woo et al 2016;Fiore et al 2017;Cresci & Maiolino 2018;Torres-Papaqui et al 2020). However, what role these OFs play in the evolution of the AGN host galaxies is still an open question, as multifrequency observations are difficult to interpret when following one unifying model (Harrison et al 2018;Smirnova-Pinchukova et al 2022;Harrison et al 2023;Speranza et al 2024) and evidence of feedback is either negative (Chen et al 2019;Shimizu et al 2019;Shin et al 2019;Torres-Papaqui et al 2020;Ruschel-Dutra et al 2021;Molina et al 2022;Tripodi et al 2022;Kakkad et al 2023) or ambiguous (Fluetsch et al 2019;Scholtz et al 2020;Wylezalek et al 2020;Luo et al 2021;Tamhane et al 2022;Kharb & Silpa 2023;Kim et al 2023;Salomé et al 2023;Veilleux et al 2023).…”