Calibrating AGN Feedback in Clusters

TL;DR

This paper presents a method using X-ray imaging data from Chandra to map and analyze heating processes in galaxy cluster cores, providing spatial constraints on AGN feedback mechanisms.

Contribution

It introduces a novel approach to constrain spatial variations in heating in cluster cores using imaging data, complementing spectral analysis.

Findings

Heating maps reveal spatial variations in cluster cores.

Method constrains location and magnitude of heating.

Combines X-ray imaging with radio data for model discrimination.

Abstract

Whether caused by AGN jets, shocks, or mergers, the most definitive evidence for heating in cluster cores comes from X-ray spectroscopy. Unfortunately such spectra are essentially limited to studying the emission spectrum from the cluster as a whole. However since the same underlying emission measure distribution produces both the observed CCD and RGS spectra, X-ray imaging can still provide spatial information on the heating process. Using Chandra archival data for a sample of 9 clusters, we demonstrate how imaging data can be used to constrain departures from a canonical, isobaric cooling flow model as a function of position in a given cluster. The results of this analysis are also shown for the deep archival exposure of the Perseus cluster. Such heating maps can provide constraints on both the location and magnitude of the heating in the cores of clusters. When combined with detections and spectral index maps from low-frequency radio observations, these maps can be used to distinguish between different models for heating in these objects.