We present Gemini Multi-Object Spectrograph (GMOS) integral field unit (IFU) observations of six massive (M ∗ ≥ 1011 M o˙) A-star dominated post-starburst galaxies at z ∼ 0.6. These galaxies are a subsample of the SQuIGGLE Survey, which selects intermediate-redshift post-starbursts from the Sloan Digital Sky Survey spectroscopic sample (DR14) with spectral shapes that indicate they have recently shut off their primary epoch of star formation. Using Hδ A absorption as a proxy for stellar age, we constrain five of the galaxies to have young (∼600 Myr) light-weighted ages at all radii and find that the sample on average has flat age gradients. We examine the spatial distribution of mass-weighted properties by fitting our profiles with a toy model including a young, centrally concentrated burst superimposed on an older, extended population. We find that galaxies with flat Hδ A profiles are inconsistent with formation via a central secondary starburst. This implies that the mechanism responsible for shutting off this dominant episode of star formation must have done so uniformly throughout the galaxy.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science