Resolving the Interstellar Medium in Ultraluminous Infrared QSO Hosts
  with ALMA
  We present ALMA observations of the CO(1-0) line and 3-mm continuum emission
in eight ultraluminous infrared (IR) quasi-stellar objects (QSOs) at z =
0.06-0.19. All eight IR QSO hosts are clearly resolved in their CO molecular
gas emission with a median source size of 3.2 kpc, and seven out of eight
sources are detected in 3-mm continuum, which is found to be more centrally
concentrated with respect to molecular gas with sizes of 0.4-1.0 kpc. Our
observations reveal a diversity of CO morphology and kinematics for the IR QSO
systems which can be roughly classified into three categories, rotating gas
disk with ordered velocity gradient, compact CO peak with disturbed velocity,
and multiple CO distinct sources undergoing a merger between luminous QSO and a
companion galaxy separated by a few kpc. The molecular gas in three of IR QSO
hosts are found to be rotation-dominated with the ratio of the maximum rotation
velocity to the local velocity dispersion of $V_{\rm rot}/\sigma=4-6$. Basic
estimates of the dynamical masses within the CO-emitting regions give masses
between $7.4\times10^9$ and $6.9\times10^{10}$ $M_\odot$. We find an increasing
trend between BH mass accretion rate and star formation rate (SFR) over three
orders of magnitude in far-IR luminosity/SFR, in line with the correlation
between QSO bolometric luminosity and SF activity, indicative of a likely
direct connection between AGN and SF activity over galaxy evolution timescales.
