Starburst-driven superwinds in quasar host galaxies
  During five decades astronomers have been puzzled by the presence of strong
absorption features including metal lines, observed in the optical and
ultraviolet spectra of quasars, signalling in- and outflowing gas winds with
relative velocities up to several thousands of km/sec. In particular the
location of these winds - close to the quasar, further out in its host galaxy,
or in its direct environment - and the possible impact on their surroundings
have been issues of intense discussion and uncertainty. Using our Herschel
Space Observatory data, we report a tendency for this so-called associated
metal absorption to occur along with prodigious star formation in the quasar
host galaxy, indicating that the two phenomena are likely to be interrelated,
that the gas winds likely occur on the kiloparsec scale and would then have a
strong impact on the interstellar medium of the galaxy. This correlation
moreover would imply that the unusually high cold dust luminosities in these
quasars are connected with ongoing star formation. Given that we find no
correlation with the AGN strength, the wind feedback which we establish in
these radio-loud objects is most likely associated with their host star
formation rather than with their black hole accretion.
