Deep Chandra Observations of the Extended Gas Sloshing Spiral in A2029

TL;DR

Deep Chandra observations of Abell 2029 reveal the largest known gas sloshing spiral, showing complex interactions between the intracluster medium, radio galaxy, and cooling processes in a seemingly relaxed galaxy cluster.

Contribution

This study presents the first detailed imaging of an extensive gas sloshing spiral in Abell 2029, highlighting its impact on cluster dynamics and radio galaxy morphology.

Findings

Largest continuous sloshing spiral observed to date.

Interaction between sloshing gas and radio galaxy causes WAT morphology.

Sloshing may help prevent excessive cooling in the cluster core.

Abstract

Recent X-ray observations of galaxy clusters have shown that there is substructure present in the intracluster medium (ICM), even in clusters that are seemingly relaxed. This substructure is sometimes a result of sloshing of the ICM, which occurs in cool core clusters that have been disturbed by an off-axis merger with a sub-cluster or group. We present deep Chandra observations of the cool core cluster Abell 2029, which has a sloshing spiral extending radially outward from the center of the cluster to approximately 400 kpc at its fullest extent---the largest continuous spiral observed to date. We find a surface brightness excess, a temperature decrement, a density enhancement, an elemental abundance enhancement, and a smooth pressure profile in the area of the spiral. The sloshing gas seems to be interacting with the southern lobe of the central radio galaxy, causing it to bend and giving the radio source a wide-angle tail (WAT) morphology. This shows that WATs can be produced in clusters that are relatively relaxed on large scales. We explore the interaction between heating and cooling in the central region of the cluster. Energy injection from the active galactic nucleus (AGN) is likely insufficient to offset the cooling, and sloshing may be an important additional mechanism in preventing large amounts of gas from cooling to very low temperatures.