We characterise the distribution of quasars within dark matter halos using a direct measurement technique for the first time at redshifts as high as $z sim 1$. Using the Planck Sunyaev-Zeldovich (SZ) catalogue for galaxy groups and the Sloan Digital Sky Survey (SDSS) DR12 quasar dataset, we assign host clusters/groups to the quasars and make a measurement of the mean number of quasars within dark matter halos as a function of halo mass. We find that a simple power-law fit of $logleft <Nright> = (2.11 pm 0.01) log (M) -(32.77 pm 0.11)$ can be used to model the quasar fraction in dark matter halos. This suggests that the quasar fraction increases monotonically as a function of halo mass even to redshifts as high as $zsim 1$.
Download