Integrated field spectroscopy of E+A (post-starburst) galaxies with the Kyoto tridimensional spectrograph II

Abstract

We have performed two-dimensional spectroscopy of three nearby E+A (post-starburst) galaxies with the Kyoto tridimensional spectrograph II (Kyoto3DII) integral field spectrograph. In all the cases, Hδ absorption is stronger at the centre of the galaxies, but significantly extended at the scale of a few kiloparsec. For one galaxy (J1656), we found a close companion galaxy at the same redshift. The galaxy turned out to be a star-forming galaxy with a strong emission in Hγ. For the other two galaxies, we have found that the central post-starburst regions possibly extend toward the direction of the tidal tails. Our results are consistent with the merger/interaction origin of E+A galaxies, where the infalling-gas possibly caused by galaxy-galaxy merging creates a central starburst, succeeded by a post-starburst (E+A) phase once the gas is depleted. © 2008 RAS.