The Determination of the Morphological Types of Galaxy Clusters Using Cluster Cartography

Abstract

We discuss the possibility of using the Cluster Cartography set for the determined the morphological types of galaxy clusters. The applied morphological scheme was proposed by Panko (2013). The morphological types are determined using numerical criteria based on three parameters: concentration to the cluster center, the signs of preferential direction or plane in the cluster (filamentary substructure), and the positions of the brightest galaxies. However, structures like galaxy clusters need visual preview for classification. The Cluster Cartography set constructs the individual cluster map in different forms and allows to estimate previously cluster type.

The Peculiarities in O-Type Galaxy Clusters

“…This way of evolution is confirmed by increase the ellipticity with redshift for low-redshift galaxy clusters and groups (Biernacka et al, 2009). According to ellipticity determination (Panko & Flin, 2006) the "flatness signs" -belts and strips -can be connected with DM distribution inside the clusters and/or between nearest large-scale structures, as was founded by Dietrich et al (2012) for A222 and A223 clusters. Some years before hot gas filament connecting both clusters was traced in X-ray by Werner et al (2008).…”

“…The designations can be combined, for example CF cD or ILP. Note, the clusters CL-type were not found (Panko, 2013). The fact can be understanding taking into consideration the direction of evolution of galaxy clusters from O-type (independently from "flatness signs") to C -type (Struble & Rood, 1982).…”

“…(1997) and López-Cruz & Gaztanaga (2001) approach. Improved and integrated scheme (Panko, 2013) allows to assign the morphological types corresponding to cluster "concentration" (from C -compact, to Iintermediate, and O -open), "flatness signs" (L -line or F -flat, and no symbol if no indication of "flatness sign" is present) and the role of bright galaxies (cD or BG, if the bright cluster members role is significant). Other peculiarities are noted as P. "Flatness signs" can correspond to filamentary substructure or preferential plane in cluster.…”

Detailed Morphology of the Rich Concentrated Galaxy Clusters

“…N can be 3, 5, 7, 9 or 11 and the width of each band is 1/N part of diameter of cluster. The numbers of galaxies in the bands are recalculated to weighted densities of galaxies (Panko & Emelyanov, 2015). It allows to describe overdense features as L11 or L9 for L-cluster and F7 or F5 for F-clusters (the numeral part corresponds N ).…”

Linear Substructures in Galaxy Clusters

“…The Cluster Cartography set (hereafter CC) was created for simplification of the galaxy clusters classification (Panko & Emelyanov, 2015). As a result, it was established the linear substructures present as peculiarities in about 50% of rich galaxy clusters.…”