Integral field spectroscopy of two H i-rich E+A galaxies

Approximately half of the nearby E+A galaxies followed up with 21-cm observations have detectable H i emission. The optical spectra of these galaxies show strong post-starburst stellar populations but no optical emission lines implying star formation is not ongoing despite the presence of significant gas reservoirs. We have obtained integral field spectroscopic follow-up observations of the two brightest, and nearest, of the six E+A galaxies with H i 21-cm emission in the recent sample of Zwaan et al. In the central regions of both galaxies, the observations are consistent with a post-starburst population with little emission. However, outside the central regions both galaxies have strong optical emission lines, with a clumpy or knot-like distribution, indicating ongoing star formation. We conclude that in these two cases, the presence of optical spectra lacking evidence for star formation while a large gas mass is present can be explained by an aperture effect in selecting the nearby E+A galaxies using single-fibre spectroscopy that probes only the galaxy core.