Star Formation in Quasar Host Galaxies at Redshift 6: Millimeter Surveys
  and New Insights from ALMA
  We have been carrying out a systematic survey of the star formation and ISM
properties in the host galaxies of z~6 quasars. Our 250 GHz observations,
together with available data from the literature, yield a sample of 14 z~6
quasars that are bright in millimeter dust continuum emission with estimated
FIR luminosities of a few 10^12 to 10^13 Lsun. Most of these
millimeter-detected z~6 quasars have also been detected in molecular CO line
emission, indicating molecular gas masses on order of 10^10 Msun. We have
searched for [C II] 158 micron fine structure line emission toward four of the
millimeter bright z~6 quasars with ALMA and all of them have been detected. All
these results suggest massive star formation at rates of about 600 to 2000
Msun/yr over the central few kpc region of these quasar host galaxies.
