An empirical picture for the evolution of galaxies outside of clusters

The main goal of this work is to study the properties of isolated elliptical galaxies with the hope of learning about their formation and evolution. A sample that contains ∼ 25% of the galaxies classified as ellipticals in the Karachentseva Catalog of Isolated Galaxies is investigated. Approximately one halt of these galaxies appear to be misclassified, a result which may imply a reduction of the percentage of ellipticals in the Karachentseva catalog to (6 ± 2)% of the total population of isolated galaxies. A significant number of merger candidates has also been found among the isolated galaxies. It is argued that the fraction of merger candidates to isolated ellipticals can be used to constrain models for the evolution of compact groups into isolated galaxies.