X-shooter reveals powerful outflows in z~1.5 X-ray selected obscured
  quasi stellar objects
  We present X-shooter at the Vewry Large Telescope observations of a sample of
10 luminous, X-ray obscured QSOs at z$\sim1.5$ from the XMM-COSMOS survey,
expected to be caught in the transitioning phase from starburst to active
galactic nucleus (AGN)-dominated systems. The main selection criterion is X-ray
detection at bright fluxes (L$>=10^{44}$ erg s$^{-1}$) coupled to red
optical-to-NIR-to-MIR colors. Thanks to its large wavelength coverage,
X-shooter allowed us to determine accurate redshifts from the presence of
multiple emission lines for five out of six targets for which we had only a
photometric redshift estimate, with an 80 percent success rate, significantly
larger than what is observed in similar programs of spectroscopic follow-up of
red QSOs. We report the detection of broad and shifted components in the
[OIII]$\lambda\lambda$5007,4959 complexes for six out of eight sources with
these lines observable in regions free from strong atmospheric absorptions. The
full width half-maximum (FWHM) associated with the broad components are in the
range FWHM$\sim900-1600$ km s$^{-1}$, larger than the average value observed in
SDSS Type 2 AGN samples at similar observed [OIII] luminosity, but comparable
to those observed for QSO/ultraluminous infrared galaxies systems for which the
presence of kpc scale outflows have been revealed through integral field unit
spectroscopy. Although the total outflow energetics (inferred under reasonable
assumptions) may be consistent with winds accelerated by stellar processes, we
favour an AGN origin for the outflows given the high outflow velocities oberved
(v$>1000$ km s$^{-1}$) and the presence of strong winds also in objects
undetected in the far infrared.
