Fast and slow rotators in the densest environments: a FLAMES/GIRAFFE integral field spectroscopy study of galaxies in A1689 at z=0.183

Abstract

We present FLAMES/GIRAFFE integral field spectroscopy of 30 galaxies in the massive cluster A1689 at z = 0.183. Conducting an analysis similar to that of ATLAS3D, we extend the baseline of the kinematic morphology–density relation by an order of magnitude in projected density and show that it is possible to use existing instruments to identify slow and fast rotators beyond the local Universe. We find 4.5 ± 1.0 slow rotators with a distribution in magnitude similar to those in the Virgo cluster. The overall slow rotator fraction of our A1689 sample is 0.15 ± 0.03, the same as in Virgo using our selection criteria. This suggests that the fraction of slow rotators in a cluster is not strongly dependent on its density. However, within A1689, we find that the fraction of slow rotators increases towards the centre, as was also found in the Virgo cluster.