Estimation of the cross-correlation length in MQN01. Top panel: Source CO line luminosities as a function of radial distance from the central quasar. The gray band shows the 5σ limiting luminosities of our survey (see text for further details). Central panel: Cumulative source number counts in MQN01 (red bins) and that expected in blank fields (black line, with their uncertainties shown in gray). Bottom panel: Projected volume-integrated cross correlation function in MQN01 (blue bins), the best-fit model (solid blue line), and the random draw from our Monte Carlo simulation (in gray). The inset panel shows the posterior distribution of the three-dimensional cross-correlation length with red lines indicating the 16th, 50th, and 84th percentile, respectively.