Hidden (absorbed) Cooling Flows V: Groups and Galaxies including Spirals

TL;DR

This paper analyzes X-ray spectra of galaxy groups, elliptical galaxies, and spirals, revealing hidden cooling flows with cold gas absorption, and finds AGN feedback insufficient to prevent cooling in these systems.

Contribution

It extends the study of hidden cooling flows to a broader range of galaxy types, including spirals, and demonstrates their presence across different galaxy environments.

Findings

All studied galaxy groups show absorbed cooling flows.

AGN feedback is ineffective in heating the inner cooling gas.

Spiral galaxies may also host similar cooling flows.

Abstract

Cooling flows are observed in X-ray studies of the centres of cool core clusters, galaxy groups and individual elliptical galaxies. They are partly hidden from direct view by embedded cold gas so have been called Hidden Cooling Flows. X-ray spectra from the XMM RGS reveal emission from hot gas modified by photoelectric absorption by cold gas intrinsic to the flow. Here we present the spectral analysis of 6 more low redshift galaxy groups ranging from the nearest fossil group to 2 groups hosting bright radio sources. All reveal absorbed cooling flows. AGN feedback is ineffective in heating the inner cooling gas in groups and elliptical galaxies. We have extended the analysis to include 3 nearby spiral galaxies (the Sombrero, Whirlpool and Sculptor galaxies). They have similar absorbed soft X-ray spectra to elliptical galaxies and may also host cooling flows of 0.3 to 1.1\Msun/yr in their CircumGalactic Medium.