SDSS J103913.70+533029.7: A Super Star Cluster in the Outskirts of a Galaxy Merger

Abstract

We describe the serendipitous discovery in the spectroscopic data of the Sloan Digital Sky Survey of a starlike object, SDSS J103913.70+533029.7, at a heliocentric radial velocity of +1012 km s -1. Its proximity in position and velocity to the spiral galaxy NGC 3310 suggests an association with the galaxy. At this distance, SDSS J103913.70+533029.7 has the luminosity of a super star cluster and a projected distance of 17 kpc from NGC 3310. Its spectroscopic and photometric properties imply a mass of > 10 6 M⊙ and an age close to that of the tidal shells seen around NGC 3310, suggesting that it formed in the event that formed the shells. © 2006. The American Astronomical Society. All rights reserved.