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 .

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 near 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 ^ { \prime \prime } \sim 200 pc , around the very nucleus .
The extreme continuum blue component was detected only to the south of the very nucleus .
This area is coincident with the region where we previously suggested that the galactic wind is cleaning the nuclear dust .

Very deep three-dimensional ( 3D ) spectra and maps clearly show that the BAL systems i and ii –mainly in the strong “ absorption lines ” Na ID \lambda 5889-95 and Ca ii K \lambda 3933– are extended ( reaching \sim 1.4–1.6 ^ { \prime \prime } \sim 1.2–1.3 kpc , from the nucleus ) and clearly elongated at the position angle ( PA ) close to the radio jet PA .
Which suggest that the BAL systems i and ii are “ both ” associated with the radio jet .

The physical properties of the four expanding nuclear bubbles were analysed , using the GMOS 3D spectra and maps .
In particular , we found strong multiple LINER/OF emission line systems and Wolf Rayet features in the main knots of the more external super bubble S1 ( r = 3.0 kpc ) .
The kinematics of these knots –and the internal bubbles– suggest that they are associated with an area of rupture of the shell S1 ( at the south-west ) .
In addition , in the more internal super bubble S4 and close to the very nucleus ( for r < 0.7 " \sim 0.6 kpc ) , two similar narrow emission line systems were detected , with strong [ S ii ] and [ O i ] emission and \Delta V \sim –200 km s ^ { -1 } .
These results suggest that an important part of the nuclear NLR is generated by the OF process and the associated low velocity ionizing shocks .

Finally , the nature of the composite BAL systems and very extended OF process –of 50 kpc– in Mrk 231 ( and similar QSOs ) are discussed .
In addition , the “ composite hyper–wind scenario ” ( already proposed for BALs ) is suggested for the origin of giant Ly \alpha blobs .
The importance of study the end phases of Mrk 231 , and similar evolving elliptical galaxies and QSOs ( i.e. , galaxy remnants ) is discussed .