Clear evidence for the early triggering of a luminous quasar-like AGN in
  a major, gas rich merger
  We present deep, intermediate resolution, long slit Gemini GMOS-S optical
spectra of the SDSS type II quasar J002531-104022, which is a highly disturbed
system currently undergoing a major merger event. We use these data to model
the ages and reddenings of the stellar populations in three distinct spatial
regions and find a remarkable uniformity in the properties of the young stellar
populations (YSP) that dominate the optical spectra. The YSPs are all found to
have relatively young ages (tysp < 40$ Myr), strongly implying that the latest
episode of star formation and quasar activity have been triggered
quasi-simultaneously. The lack of reddening deduced from both continuum
modelling and the measured Balmer decrements (E(B-V) <0.3) suggests that
starburst and/or AGN induced outflows have already effectively removed a
substantial proportion of the gas and dust from the central region. These
findings starkly contrast with model predictions which suggest an offset of a
few 100 Myr between the peak of merger induced star formation and the emergence
of the optically visible quasar activity. Based on our stellar population fits
we also show that the total stellar mass is in the range (4 - 17) X 10^10 solar
masses, lower than typically found for quasar host galaxies.
