Internal Kinematics and Stellar Populations of the Poststarburst+AGN
  Galaxy SDSS J230743.41+152558.4
  We present the first 3D spectroscopic observations of a nearby HI detected
poststarburst, or E+A, galaxy, SDSS J230743.41+152558.4, obtained with the
VIMOS IFU spectrograph at ESO VLT. Using the NBursts full spectral fitting
technique, we derive maps of stellar kinematics, age, and metallicity out to
2-3 half-light radii. Our analysis reveals a large-scale rapidly rotating disc
(v_circ = 300km/s) with a positive age gradient (0.6 to 1.5 Gyr), and a very
metal-rich central region ([Fe/H]=+0.25 dex). If a merger or interaction is
responsible for triggering the starburst, the presence of this undisturbed disc
suggests a minor merger with a gas-rich satellite as the most plausible option,
rather than a disruptive major merger. We find spectroscopic evidence for the
presence of a LINER or AGN. This is an important clue to the feedback mechanism
that truncated the starburst. The presently observed quiescent phase may well
be a temporary episode in the galaxy's life. SDSS J230743.41+152558.4 is
gas-rich and may restart forming stars, again becoming blue before finally
settling at the red sequence.
