Anomalously Blue Ellipticals in the Sloan Survey

ORAL

Abstract

Recently, we identified two isolated early-type galaxies with unusually blue optical colors (Marcum etal, AJ 127, 3213), indicating current or recent massive star formation. Merger-induced star formation is the most likely mechanism for the odd photometric properties of these systems, yet, interestingly, they do not show the strong morphological scars (tidal tails, shells) generally attributed to merger activity. We concluded that these systems are late stage mergers, in which those morphological scars have largely dissipated, but photometric anomalies remain. To further explore the evolutionary paths of elliptical galaxies, we are ``mining'' the Sloan Digital Sky Survey for anomalously blue ellipticals, which may represent local universe analogues to distant young galaxies. We will describe representative objects and outline their properties.

Authors

  • Michael Fanelli

    Texas Christian University, TCU, Department of Physics and Astronomy, Texas Christian University

  • Pamela Marcum

    TCU, NASA HQ, TCU \& NASA Headquarters

  • Chris Fuse

    Texas Christian University