Suzaku Observation of Group of Galaxies NGC 507: Temperature and Metal Distributions in the Intra-cluster Medium

TL;DR

This study used Suzaku to analyze the temperature and metal distribution in the intra-cluster medium of NGC 507, revealing detailed abundance gradients and metal mass-to-light ratios, and comparing these with other galaxy systems.

Contribution

First measurement of OMLR and MMLR to the outer regions of a galaxy group with Suzaku, and detailed analysis of abundance gradients and metal ratios in NGC 507.

Findings

Steeper abundance gradients for Mg, Si, S, and Fe compared to O in the core.

Higher metal mass-to-light ratios in hotter, richer systems.

No significant asymmetry in the hardness ratio map.

Abstract

Temperature and abundance distributions of the intra-cluster medium (ICM) in the NGC 507 group of galaxies were studied with Suzaku. Observed concentric annular spectra were well-represented by a two temperature model for ICM, and we found steeper abundance gradients for Mg, Si, S, and Fe compared with O in the central region. Abundance ratios of alpha-elements to iron were found to be similar to those in other groups and poor clusters. We calculated metal mass-to-light ratios for Fe, O and Mg (IMLR, OMLR, MMLR) for NGC 507, and values for different systems were compared. Hotter and richer systems tend to show higher values of IMLR, OMLR, and MMLR. OMLR and MMLR were measured to an outer region for the first time with Suzaku, while IMLR was consistent with that with ASCA. We also looked into 2-dimensional map of the hardness ratio, but found no significant deviation from the circular symmetry.