IR mergers and IR QSOs with galactic winds. III. Mrk 231: composite outflow with multiple expanding bubbles and BALs (an exploding young QSO?)

A study of outflow (OF) and BAL systems in Mrk 231 (and in similar IR QSOs) is presented. This study is based mainly on 1D and 2D spectroscopy (obtained at La Palma/WHT, HST, IUE, ESO/NTT, KPNO, APO and CASLEO observatories) plus HST images. For Mrk 231 we report evidence that the extreme nuclear OF process has at least 3 main components on different scales, which are probably associated with: (i) the radio jet, at pc scale; and (ii) the extreme starburst at pc and kpc scale. This OF has generated 4 or more concentric expanding bubbles and the BAL systems. Specifically, inside and very close to the nucleus the 2D spectra show the presence of an OF emission bump in the blend H α +[N ii ], with with LINER/OF processes associated with fast velocity shocks. Therefore, we suggest that these giant bubbles are associated with the large scale nuclear OF component, which is generated –at least in part– by the extreme nuclear starburst: i.e., type II SN explosions. The variability of the short lived BAL–III Na ID system was studied, covering almost all the period in which this system appeared (between ∼ 1984–2004). We found that the BAL-III light curve (LC) is clearly asymmetric with: a steep increase, a clear maximum and an exponential fall (similar to the shape of a SN LC). The origin of this BAL-III system is discussed, mainly in the frame work of an extreme explosive event , probably associated with giant SNe/hypernova explosions. Finally, the IR colours diagram and the UV-BAL systems of IR+GW/OF+Fe ii QSOs are analysed. This study shows a new BAL IR QSO and suggest/confirm that these objects could be nearby young BAL QSOs, similar to those detected recently at z ∼ 6.0 . We propose that the phase of young QSO is associated with: accretion of large amount of gas (by the SMBH) + extreme starbursts + extreme composite OFs/BALs.