  The last solar minimum is characterized by several peculiar aspects and by
the presence of a complex magnetic topology with two different kinds of coronal
streamers: pseudo-streamers and bipolar streamers. Pseudo-streamers or unipolar
streamer are coronal structures which separate coronal holes of the same
polarity, without a current sheet in the outer corona; unlike bipolar streamer
that separate coronal holes of opposite magnetic polarity. In this study, two
examples of these structures have been identified in the period of Carrington
rotation 2067, by applying a potential-field source-surface extrapolation of
the photospheric field measurements. We present a spectroscopic analysis of a
pseudo-streamer and a bipolar streamer observed in the period 12-17 March 2008
at high spectral and spatial resolution by the Ultraviolet Coronagraph
Spectrometer (UVCS; Kohl et al., 1995) onboard Solar and Heliospheric
Observatory (SOHO). The solar wind plasma parameters, such as kinetic
temperature, electron density and outflow velocity, are inferred in the
extended corona (from 1.7 to 2.1 Rsun) analysing the O VI doublet and Ly alpha
line spectra.
  The coronal magnetic topology is taken into account and has been extrapolated
by a 3D magneto-hydrodynamic model of the global corona. The results of the
analysis show some peculiarities of the pseudo-streamer physical parameters in
comparison with those obtained for bipolar streamers: in particular, we have
found higher kinetic temperature and higher outflow velocities of O VI ions and
lower electron density values. In conclusion, we point out that
pseudo-streamers produce a "hybrid" type of outflow that is intermediate
between slow and fast solar wind and they are a possible source of slow/fast
wind in not dipolar solar magnetic field configuration.
