X-ray active galactic nuclei in the core of the Perseus cluster

TL;DR

This study analyzes X-ray emissions from galaxy nuclei in the Perseus cluster core, revealing properties of active galactic nuclei and their black holes, with no clear correlation between luminosities and galaxy or black hole mass.

Contribution

First detailed Chandra X-ray analysis of galaxy nuclei in the Perseus cluster core, characterizing their spectral components and examining correlations with galaxy and black hole properties.

Findings

X-ray point sources found in 13 galaxy nuclei and NGC1275.

Spectral analysis shows steep power-law and thermal components.

No correlation between X-ray luminosity and galaxy brightness or black hole mass.

Abstract

We present a study of the X-ray emission from the nuclei of galaxies observed in the core of the Perseus cluster in a deep exposure with Chandra. Point sources are found coincident with the nuclei of 13 early-type galaxies, as well as the central galaxy NGC1275. This corresponds to all galaxies brighter than M_B = -18 in the Chandra field. All of these sources have a steep power-law spectral component and four have an additional thermal component. The unabsorbed power-law luminosities in the 0.5-7.0 keV band range from 8.10^38-5.10^40 erg/s. We find no simple correlations between the K band luminosity, or the FUV and NUV AB magnitudes of these galaxies and their X-ray properties. We have estimated the black hole masses of the nuclei using the K band M_BH-L_K relation and again find no correlation between black hole mass and the X-ray luminosity. Bondi accretion onto the black holes in the galaxies with mini-haloes should make them much more luminous than observed.