Morphology, color-magnitude and scaling relations of galaxies in Abell 426

TL;DR

This study analyzes the photometric and structural properties of 183 galaxies in Abell 426, establishing key scaling relations like the Kormendy relation and Fundamental Plane for different galaxy types, revealing insights into galaxy morphology and evolution.

Contribution

It provides detailed morphological classification, multi-component decomposition, and scaling relations for galaxies in Abell 426, including new insights into dwarf ellipticals and low-mass ETGs.

Findings

Over 80% of members are early-type galaxies following the red sequence.

The Kormendy relation slope is 3.02 with a zero-point of 18.65 in the r-band.

Low-mass ETGs follow a parallel Kormendy relation with a fainter zero-point.

Abstract

We present photometric properties of 183 member galaxies in the Abell 426 cluster using the Sloan Digital Sky Survey (SDSS) imaging and spectroscopic observation. Detailed morphology based on visual classification followed by multi-component image decomposition of 179 galaxies is presented in the SDSS g, r, i-bands. More than 80 percent of the members are Early-type galaxies (ETGs), with elliptical, dwarf elliptical (dE), and lenticular morphology and follow the red-sequence in the color-magnitude diagram (CMD). With a few dEs and spirals in the blue cloud, the cluster CMD is nearly unimodal.The dEs are $\sim2$-mag fainter and follow a different Sersic index and central velocity dispersion distribution than their bright counterparts. Further, we establish the Kormendy relation (KR) and the Fundamental Plane relation (FPR) for 5 different samples of ETGs constructed based on derived physical parameters such as Sersic index, concentration, central velocity dispersion in g, r, i-bands. The mean r-band slope and zero-point of the KR are $3.02\pm0.1$ and $18.65\pm0.03$ in close agreement to other cluster ellipticals in the local and higher redshift. Kinematics-based ETG sample produces the least scatter in KR with zero-point getting brighter by $\sim1.3$-mag from g to i band. The dEs and other low-mass ETGs follow the KR with a similar slope but with $\sim1.3$-mag fainter zero-point and form a parallel KR. The bright ellipticals follow an FPR with $a=1.37\pm0.003$, $b=0.35\pm0.05$ and $c=- 9.37\pm0.02$ in the r-band; galaxies tend to deviate from this relation at the low-mass end. A catalog with morphology and 2D structural analysis is available online.