Far infra-red emission lines in high redshift quasars
  We present Plateau de Bure Interferometer observations of far infra-red
emission lines in BRI 0952-0115, a lensed quasar at z=4.4 powered by a
super-massive black hole (M_BH=2x10^9 M_sun). In this source, the resolved map
of the [CII] emission at 158 micron allows us to reveal the presence of a
companion galaxy, located at \sim 10 kpc from the quasar, undetected in optical
observations. From the CO(5-4) emission line properties we infer a stellar mass
M*<2.2x10^10 M_sun, which is significantly smaller than the one found in local
galaxies hosting black holes with similar masses (M* \sim 10^12 M_sun). The
detection of the [NII] emission at 205 micron suggests that the metallicity in
BRI 0952-0115 is consistent with solar, implying that the chemical evolution
has progressed very rapidly in this system. We also present PdBI observations
of the [CII] emission line in SDSSJ1148+5251, one of the most distant quasar
known, at z=6.4. We detect broad wings in the [CII] emission line, indicative
of gas which is outflowing from the host galaxy. In particular, the extent of
the wings, and the size of the [CII] emitting region associated to them, are
indicative of a quasar-driven massive outflow with the highest outflow rate
ever found (dM/dt>3500 M_sun/yr).
