2022ApJ...930...27L

We present high spatial resolution (∼0.''4, 2.2 kpc) observations of the CO(6-5), CO(7-6), and [C I]_369 µm_ lines and dust continuum emission from the interstellar medium (ISM) in the host galaxy of the quasar J0305-3150 at z = 6.6. These, together with archival [C II]_158 µm_ data at a comparable spatial resolution, enable studies of the spatial distribution and kinematics between the ISM in different phases. When comparing the radial profiles of CO, [C II]_158 µm_, and the dust continuum, we find that the CO and dust continuum exhibit similar spatial distributions, both of which are less extended than the [C II]_158 µm_, indicating that the CO and dust continuum are tracing the same gas component, while the [C II]158 µm is tracing a more extended one. In addition, we derive the radial profiles of the [C II]_158 µm_/CO, [C II]_158 µm_/far-infrared (FIR), CO/FIR, and dust continuum S_98.7 GHz_/S258.1 GHz_ ratios. We find a decreasing S_98.7 GHz_/S258.1 GHz_ ratio with radius, possibly indicating a decrease of dust optical depth with increasing radius. We also detect some of the ISM lines and continuum emission in the companion galaxies previously discovered in the field around J0305-3150. Through comparing the line-to-line and line-to-FIR ratios, we find no significant differences between the quasar and its companion galaxies.