CGCG 480-022: A Distant Lonesome Merger?

Abstract

We present a complete analysis, which includes morphology, kinematics, stellar populations, and N-body simulations, of CGCG 480Ϫ022, the most distant ( km s Ϫ1 ) isolated galaxy studied so far in such cz p 14,317 detail. The results all support the hypothesis that this galaxy has suffered a major merger event with a companion of ∼0.1 times its mass. Morphology reveals the presence of a circumnuclear ring and possibly further ring debris. The radial velocity curve looks symmetrical, while the velocity dispersion increases with radius, reaching values that do not correspond to a virialized system. Moreover, this galaxy deviates significantly from the fundamental plane and the Faber-Jackson relation. The stellar population analysis show that the ring is younger and more metal-rich, which suggest that it has undergone a fairly recent burst of star formation. Both morphological and dynamical results are in broad agreement with our N-body simulations.