Multi-wavelength structure analysis of local cluster galaxies. The WINGS project

TL;DR

This study analyzes how galaxy structures in clusters vary across multiple wavelengths, revealing that galaxy concentration remains stable while size decreases with wavelength, with differences observed between cluster and non-member galaxies.

Contribution

It provides a multi-wavelength structural analysis of cluster galaxies using GALAPAGOSII, highlighting differences in size and concentration between cluster and non-member galaxies.

Findings

Sersic index remains nearly constant across wavelengths for cluster galaxies.

Effective radius decreases with increasing wavelength for all galaxy types.

Bright cluster galaxies are more concentrated and compact than non-member galaxies.

Abstract

We present a multi-wavelength analysis of the galaxies in nine clusters selected from the WINGS dataset, examining how galaxy structure varies as a function of wavelength and environment using the state of the art software GALAPAGOSII. We simultaneously fit single S\'ersic functions on three optical (u, B and V) and two near-infrared (J and K) bands thus creating a wavelength-dependent model of each galaxy. We measure the magnitudes, effective radius ($R_{e}$) the S\'ersic index ($n$), axis ratio and position angle in each band. The sample contains 790 cluster members (located close to the cluster center < 0.64 R$_{200}$ and 254 non-member galaxies that we further separate based on their morphology into ellipticals, lenticulars and spirals. We find that the S\'ersic index of all galaxies inside clusters remains nearly constant with wavelength while $R_{e}$ decreases as wavelength increases for all morphological types. We do not observe a significant variation on n and $R_{e}$ as a function of projected local density and distance from the clusters center. Comparing the n and $R_{e}$ of bright cluster galaxies with a subsample of non-member galaxies we find that bright cluster galaxies are more concentrated (display high $n$ values) and are more compact (low $R_{e}$). Moreover, the light profile ($\mathcal{N}$) and size ($\mathcal{R}$) of bright cluster galaxies does not change as a function of wavelength in the same manner as non-member galaxies.