In-depth Chandra study of the AGN feedback in Virgo elliptical galaxy M84

TL;DR

This study uses deep Chandra X-ray observations to analyze the energetic interactions between the supermassive black hole and the hot interstellar medium in galaxy M84, revealing significant wave energy contributions and plasma escape phenomena.

Contribution

It provides a detailed two-dimensional thermodynamic analysis of M84's hot gas, quantifies wave energy from bubble expansion, and demonstrates plasma escape into the intergalactic medium.

Findings

Wave energy can significantly contribute to AGN energy output.

Waves are concentrated near the galaxy center and perpendicular to bubble outflows.

Radio plasma escapes from the galaxy into the intergalactic medium.

Abstract

Using deep Chandra observations of M84 we study the energetics of the interaction between the black hole and the interstellar medium of this early-type galaxy. We perform a detailed two dimensional reconstruction of the properties of the X-ray emitting gas using a constrained Voronoi tessellation method, identifying the mean trends and carrying out the fluctuation analysis of the thermodynamical properties of the hot ISM. In addition to the PV work associated with the bubble expansion, we identify and measure the wave energy associated with the mildly supersonic bubble expansion. We show that, depending on the age of the cavity and the associated wave, the waves can have a substantial contribution to the total energy release from the AGN. The energy dissipated in the waves tends to be concentrated near the center of M84 and in the direction perpendicular to the bubble outflow, possibly due to the interference of the waves generated by the expansion of northern and southern bubbles. We also find direct evidence for the escape of radio plasma from the ISM of the host galaxy into the intergalactic medium.