The clusters Abell~222 and Abell~223: a multi-wavelength view

TL;DR

This study combines optical and X-ray data to analyze the properties, interactions, and dynamical states of galaxy clusters Abell 222 and Abell 223, revealing their complex merger history and intra-cluster medium characteristics.

Contribution

It provides a detailed multi-wavelength analysis of Abell 222 and Abell 223, highlighting their different dynamical states and the connection between galaxy properties and intra-cluster medium.

Findings

Abell 222 has a well-fit Schechter galaxy luminosity function.

Abell 223's luminosity function requires a second bright component.

X-ray maps show homogeneous gas in Abell 222 and perturbed gas in Abell 223.

Abstract

(Abstract abridged) The Abell 222 and 223 clusters are located at an average redshift z ~ 0.21 and are separated by 0.26 deg. Signatures of mergers have been previously found in these clusters, both in X-rays and at opticalwavelengths, thus motivating our study. In X-rays, they are relatively bright, and Abell 223 shows a double structure. A filament has also been detected between the clusters both at optical and X-ray wavelengths. We analyse the optical properties of these two clusters based on deep imaging in two bands, derive their galaxy minosity functions (GLFs) and correlate these properties with X-ray characteristics derived from XMM-Newton data. The GLFs of Abell 222 in the g' and r' bands are well fit by a Schechter function; the GLF is steeper in r' than in g'. For Abell 223, the GLFs in both bands require a second component at bright magnitudes, added to a Schechter function; they are similar in both bands. The Serna & Gerbal method allows to separate well the two clusters. No obvious filamentary structures are detected at very large scales around the clusters, but a third cluster at the same redshift, Abell 209, is located at a projected distance of 19.2 Mpc. X-ray temperature and metallicity maps reveal that the temperature and metallicity of the X-ray gas are quite homogeneous in Abell 222, while they are very perturbed in Abell 223. The Abell 222/Abell 223 system is complex. The two clusters that form this structure present very different dynamical states. Signs of recent interactions are also detected in the optical data where this cluster shows a ``perturbed'' GLF. In summary, the multiwavelength analyses of Abell 222 and Abell 223 are used to investigate the connection between the ICM and the cluster galaxy properties in an interacting system.