  In this work we present the first results of a study of BAL QSOs (at low and
high redshift), based on very deep Gemini GMOS integral field spectroscopy. In
particular, the results obtained for the nearest BAL IR QSO Mrk 231 are
presented. Very deep three-dimensional spectra and maps clearly show that the
BAL systems I and II are extended (reaching 1.4-1.6" = 1.2-1.3 kpc, from the
nucleus) and clearly elongated at the position angle close to the radio jet PA.
Which suggest that the BAL systems I and II are both associated with the radio
jet, and supporting the bipolar jet-wind model for some BALs. For the nuclear
region of Mrk 231, the QSO and host-galaxy components were modelled, using a
new technique of decoupling 3D spectra. From this study, the following main
results were found: (i) in the pure host galaxy spectrum an extreme nuclear
starburst component was clearly observed, mainly as a very strong increase in
the flux, at the blue wavelengths; (ii) the BAL system I is observed in the
spectrum of the host galaxy; (iii) in the clean/pure QSO emission spectrum,
only broad lines were detected. 3D GMOS individual spectra (specially in the IR
Ca II triplet) and maps confirm the presence of an extreme and young nuclear
starburst (8 < age < 15 Myr), which was detected mainly in a ring or toroid
with a radius r = 0.3" = 200 pc, around the very nucleus. The physical
properties of the four expanding nuclear bubbles were analysed, using the GMOS
3D spectra and maps. These results suggest that an important part of the
nuclear NLR is generated by the OF process and the associated low velocity
ionizing shocks.
