[en] quasars: absorption lines ; radiative transfer ; methods: numerical
[en] Context. Despite all the studies, the geometry of the wind at the origin of the blueshifted broad absorption lines (BAL) observed in nearly 20% of quasars still remains a matter of debate. <BR /> Aims: We want to see if a two-component polar+equatorial wind geometry can reproduce the typical BAL profiles observed in these objects. <BR /> Methods: We built a Monte Carlo radiative transfer code (called MCRT) to simulate the line profiles formed in a polar+equatorial wind in which the photons, emitted from a spherically symmetric core are resonantly scattered. Our goal is to reproduce typical C iv line profiles observed in BAL quasars and to identify the parameters governing the line profiles. <BR /> Results: The two-component wind model appears to be efficient in reproducing the BAL profiles from the P Cygni-type profiles to the more complex ones. Some profiles can also be reproduced with a pole-on view. Our simulations provide evidence of a high-velocity rotation of the wind around the polar axis in BAL quasars with non P Cygni-type line profiles.