E+A galaxies in the near-infrared: broadband photometry.
Abstract (from CDS):
This paper presents near-IR photometry of a selected sample of southern hemisphere E+A galaxies. The sample includes 50 galaxies from nearby (z∼0.05) and distant (z∼0.3) clusters, as well as E+A galaxies from the field (z∼0.1). Observations include 13 normal early-type galaxies from the field and from clusters to be compared with the E+A sample. The photometry includes J, H, and Ks apparent magnitudes and colors. Observed colors are obtained from the apparent total magnitudes and compared with those of the GISSEL96 spectrophotometric models of galaxy evolution. There is an overall agreement between integrated colors of models and observed ones, for both the E+A galaxies located in clusters and those in the field, at z≲0.1. However, large differences between colors predicted from models and those observed in E+A galaxies located in clusters at z∼0.3 are found. We also compute rest-frame colors for all the galaxies using two different sets of K-corrections and obtain average colors for all the samples. This work investigates systematic properties of the E+A sample as a function of its environment. Result. seem to indicate that cluster E+A galaxies (at low redshift) are bluer than field E+A galaxies at z∼0.1. Even this conclusion does not depend on whether we use comoving or rest-frame colors or on the models used to obtain rest-frame colors; the difference is not significant enough, considering color dispersions between the samples. If the differences are real, they could imply a different stellar content for the E+A galaxies located in the field compared with those located in the cluster E+A galaxies.