Compact Molecular Gas Distribution in Quasar Host Galaxies

We use Atacama Large Millimeter/submillimeter Array CO(2-1) observations of six low-redshift Palomar-Green quasars to study the distribution and kinematics molecular gas their host galaxies at kpc-scale resolution. While content, fraction, star formation rates are similar those nearby massive, star-forming galaxies, quasar possess exceptionally compact, disky distributions with a median half-light radius 1.8 kpc mass surface densities $\gtrsim 22$ $M_\odot$pc$^{-2}$. overall velocity field is dominated by regular rotation out large radii, velocity-to-velocity dispersion ratio 9$, nuclear region displays substantial kinematic complexity associated small-scale substructure in distribution. A tilted-ring analysis reveals that photometric position angles misaligned on average $\sim 34 \pm 26^\circ$, provides evidence twisting. These provide tantalizing clues detailed physical conditions circumnuclear environments actively accreting supermassive black holes.