Аннотация
We test a scenario claiming that the broad absorption line (BAL) phenomenon
in quasars (QSOs) is not a temporary stage of their life. In this scenario, we
see the BAL effect only if the line of sight is within a spatially limited and
collimated massive outflow cone covering only a fraction of sky from the point
of view of the nucleus. The aim is to understand the theoretical mechanism
behind the massive outflow in BAL QSOs which is important for modelling the
impact of quasars onto the star formation rate in the host galaxy, and,
subsequently, onto the galaxy evolution. We apply the specific theoretical
model of dust-driven wind. The model has considerable predictive power. The
2.5D version of FRADO model of Czerny & Hryniewicz gives rise to the formation
of fast funnel-shaped outflow from the disk for a certain range of black hole
masses, Eddington ratios and metallicities. We now interpret BAL QSO as sources
viewed along the outflowing stream and we calculate the probabilities of seeing
the BAL phenomenon as functions of these global parameters, and we compare
these probabilities to those seen in the observational data. We include
considerations on the presence/absence of obscuring torus. Comparing our
theoretical results with observational data for a sample consisting of two
sub-populations of BAL and non-BAL QSOs we found that both in the model and in
the data the BAL phenomenon mostly happens for sources with black hole masses
larger than 10^8 solar mass, the effect get stronger with accretion rate, and
also high metallicities are more likely in QSOs showing BAL features if the
presence of torus is taken into account. The consistency of the model with the
data provides support for the interpretation of the BAL phenomenon as the
result of the orientation of the source. It also supports the underlying
theoretical model although more consistency checks should be done in the
future.
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