Anisotropic satellite galaxy quenching modulated by supermassive black hole activity

TL;DR

This study reveals that black hole activity influences satellite galaxy quenching in a directional manner, with outflows clearing the circumgalactic medium and affecting star formation, supported by observational data and simulations.

Contribution

It provides the first observational evidence linking black hole feedback anisotropy to satellite galaxy quenching patterns in massive halos.

Findings

Quiescent satellites are less frequent along the minor axis of central galaxies.

Black hole outflows clear circumgalactic medium, reducing ram pressure and preserving star formation.

Simulations show similar modulation despite isotropic black hole feedback models.

Abstract

The evolution of satellite galaxies is shaped by their constant interaction with the circum galactic medium surrounding central galaxies, which in turn may be affected by gas and energy ejected from the central supermassive black hole. However, the nature of this coupling between black holes and galaxies is highly debated and observational evidence remains scarce. Here we report an analysis of archival data on 124,163 satellite galaxies in the potential wells of 29,631 dark matter halos with masses between 10$^{12}$ and $10^{14}$ solar masses. We find that quiescent satellites are relatively less frequent along the minor axis of their central galaxies. This observation might appear counterintuitive as black hole activity is expected to eject mass and energy preferentially in the direction of the minor axis of the host galaxy. However, we show that the observed signal results precisely from the ejective nature of black hole feedback in massive halos, as active galactic nuclei-powered outflows clear out the circumgalactic medium, reducing the ram pressure and thus preserving star formation. This interpretation is supported by the IllustrisTNG suite of cosmological numerical simulations, where a similar modulation is observed even though the sub-grid implementation of black hole feedback is effectively isotropic. Our results provide compelling observational evidence for the role of black holes in regulating galaxy evolution over spatial scales differing by several orders of magnitude.