Studying star forming dwarf galaxies in Abell 779, Abell 1367, Coma, and Hercules clusters

Abstract

Context. We continue to study star formation in dwarf galaxies located in nearby clusters. Aims. Known physical and chemical relations outlining the formation and evolution of dwarfs is compared in different environments, including the Local Volume (LV) and some nearby clusters studied previously. Methods. We used the TNG telescope for four nights in 2010 to acquire deep near-infrared imaging in K of 45 star forming dwarf galaxies located in the Abell 779, Abell 1367, Abell 1656 (Coma), and Abell 2151 (Hercules) clusters. Results. Surface photometry was approached based on past experience by using the sech law to account for the outer old stellar contribution plus a Gaussian component to model the inner starburst, proving the blue compact dwarf (BCD) classification of most targets. Sech central surface brightness, semimajor axis, sech, and total apparent magnitude were measured, allowing to estimate size, absolute luminosity and mass for all targets. Conclusions. The physical correlations between size, central brightness, and NIR luminosity appear to hold, but previously known linear fits break above M SK = −19 for Abell 779, Abell 1367 and especially for Hercules, while the dwarf fundamental plane (FP) is probed by only half cluster members, suggesting harassment by the denser cluster environments. Nevertheless, the chemical relations between the oxygen abundance, luminosity, gas mass, baryonic mass, and gas fraction in a closed box model are probed by most members of the four studied clusters, and the starburst grows linearly with the K luminosity.