We have measured the velocities of 19 planetary nebulae (PNs) in the outer regions of the giant early-type galaxy NGC 4406 in the Virgo cluster. The kinematics of the outermost regions, at a mean radius of 142″ or 11 kpc, show rapid rotation and a low observed velocity dispersion (∼166 and 96 km s-1, respectively), compared with the central velocity dispersion of about 210 km s-1. This supports the classification of this galaxy as an S0. Although this galaxy has a systemic velocity of -227 km s-1, we found three PNs with velocities close to the mean velocity of the Virgo cluster (about 1400 km s-1). We argue that these three PNs may be members of an intracluster stellar population in the Virgo cluster.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science