Fornax Deep Survey (FDS) with the VST XI. The search for signs of preprocessing between the Fornax main cluster and Fornax A group
Alan H. Su, Heikki Salo, Joachim Janz, Eija Laurikainen, Aku Venhola, Reynier F. Peletier, Enrica Iodice, Michael Hilker, Michele Cantiello, Nicola Napolitano, Marilena Spavone, Maria A. Raj, Glenn van de Ven, Steffen. Mieske, Maurizio Paolillo, Massimo Capaccioli, Edwin A. Valentijn, Aaron E. Watkins
We investigate the structural properties of cluster and group galaxies by studying the Fornax main cluster and the infalling Fornax A group, exploring the effects of galaxy preprocessing in this showcase example. Additionally, we compare the structural complexity of Fornax galaxies to those in the Virgo cluster and in the field. Our sample consists of 582 galaxies from the Fornax main cluster and Fornax A group. We quantified the light distributions of each galaxy based on a combination of aperture photometry, Sérsic+PSF (point spread function) and multi-component decompositions, and non-parametric measures of morphology (Concentration C; Asymmetry A, Clumpiness S; Gini G; second order moment of light M20), and structural complexity based on multi-component decompositions. These quantities were then compared between the Fornax main cluster and Fornax A group. The structural complexity of Fornax galaxies were also compared to those in Virgo and in the field. Overall, we find significant differences in the distributions of quantities derived from Sérsic profiles (g′−r′, r′−i′, Re, and μ¯e,r′), and non-parametric indices (A and S) between the Fornax main cluster and Fornax A group. Moreover, we find significant cluster-centric trends with r′−i′, Re, and μ¯e,r′, as well as A, S, G, and M20 for galaxies in the Fornax main cluster. We find the structural complexity of galaxies increases as a function of the absolute r′-band magnitude (and stellar mass), with the largest change occurring between -14 mag ≲Mr′≲ -19 mag. This same trend was observed for galaxies in the Virgo cluster and in the field, which suggests that the formation or maintenance of morphological structures (e.g. bulges, bar) is largely dependent on the stellar mass of the galaxies, rather than their environment.