What drives galaxy quenching? A deep connection between galaxy kinematics and quenching in the local Universe

Abstract

We develop a 2D inclined rotating disc model, which we apply to the stellar velocity maps of 1862 galaxies taken from the MaNGA survey (SDSS public Data Release 15). We use a random forest classifier to identify the kinematic parameters that are most connected to galaxy quenching. We find that kinematic parameters that relate predominantly to the disc (such as the mean rotational velocity) and parameters that characterise whether a galaxy is rotation- or dispersion-dominated (such as the ratio of rotational velocity to velocity dispersion) are not fundamentally linked to the quenching of star formation. Instead, we find overwhelmingly that it is the absolute level of velocity dispersion (a property that relates primarily to a galaxy’s bulge/spheroidal component) that is most important for separating star forming and quenched galaxies. Furthermore, a partial correlation analysis shows that many commonly discussed correlations between galaxy properties and quenching are spurious, and that the fundamental correlation is between quenching and velocity dispersion. In particular, we find that at fixed velocity dispersion, there is only a very weak dependence of quenching on the disc properties, whereby more discy galaxies are slightly more likely to be forming stars. By invoking the tight relationship between black hole mass and velocity dispersion, and noting that black hole mass traces the total energy released by AGN, we argue that these data support a scenario in which quenching occurs by preventive feedback from AGN. The kinematic measurements from this work are publicly available.

The quenching of galaxies, bulges, and disks since cosmic noon

“…Finally, for a comparison of quenching in observations to cosmological hydrodynamical simulations we encourage readers to view Piotrowska et al (2021); and for a critical assessment of the dependence of quenching on kinematic parameters we encourage readers to view Brownson et al (2022). Briefly, the former establishes that the predictions from LGalaxies shown here are also remarkably similar to predictions from Eagle (Schaye et al 2015), Illustris (Vogelsberger et al 2014a,b) and Illustris-TNG (Nelson et al 2018).…”

“…Additionally, strong bimodality is observed in morphological, structural, and kinematic parameters (e.g. Driver et al 2006;Cappellari et al 2011;Simard et al 2011;Mendel et al 2014;Brownson et al 2022). In this work we generally refer to these two classes of galaxies as 'disk-dominated' (predominantly rotationally supported) and 'bulge-dominated' (predominantly pressure supported), where pure spheroids are taken to be the natural extremum of bulge-dominated systems.…”

“…Indeed, this avenue of research is leading to powerful new constraints on the physics of feedback in modern simulations (e.g. Lang et al 2014;Bluck et al 2016Bluck et al , 2019Bluck et al , 2020aTerrazas et al 2016Terrazas et al , 2020Brennan et al 2017;Piotrowska et al 2021;Brownson et al 2022).…”

Beyond Galaxy Bimodality: The Complex Interplay between Kinematic Morphology and Star Formation in the Local Universe

“…Such structures include classical bulges (possibly built up by interactions) or a dynamically hot thick disk. This idea is supported by photometric observations of higher bulge-to-total ratios in passive galaxies (e.g., Baldry et al 2004;Bundy et al 2010;Cheung et al 2012;Bluck et al 2014;Morselli et al 2017;Popesso et al 2019) and a link between bulge prominence and quenching in IFS studies (Brownson et al 2022). The growth of both classical bulges and thick disks has been attributed to mergers (e.g., Quinn et al 1993;Walker et al 1996;Aguerri et al 2001;Read et al 2008;Villalobos & Helmi 2008) or gasrelated compaction events (e.g., Tacchella et al 2016).…”

The miniJPAS survey

“…The central velocity dispersion is correlated with the mass of the central black hole of galaxies, so it is connected the AGN feedback and it has been shown to play a crucial role in quenching (see e.g. Bluck et al 2020;Brownson et al 2022).…”