Integrated field spectroscopy of E+A (post-starburst) galaxies with the Kyoto3DII

TL;DR

This study uses integral field spectroscopy to analyze the spatial distribution of post-starburst features in three nearby E+A galaxies, revealing evidence of merger or interaction origins.

Contribution

It provides detailed two-dimensional spectroscopic data showing extended post-starburst regions and signs of galaxy interactions in E+A galaxies.

Findings

Hdelta absorption is centrally concentrated but extended over a few kpc.

One galaxy has a close companion and active star formation.

Post-starburst regions may extend toward tidal tails, supporting merger scenarios.

Abstract

We have performed a two-dimensional spectroscopy of three nearby E+A (post-starburst) galaxies with the Kyoto3DII integral field spectrograph. In all the cases, Hdelta absorption is stronger at the centre of the galaxies, but significantly extended in a few kpc scale. 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 Hgamma. 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 a galaxy-galaxy merging creates a central-starburst, succeeded by a post-starburst (E+A) phase once the gas is depleted.