We examine recent high-precision measurements of small-scale quasar clustering ( at z \sim 0.5 - 2 on scales of \sim 25 ~ { } \mathrm { kpc / h } ) from the SDSS in the context of the MassiveBlackII ( MBII ) cosmological hydrodynamic simulation and conditional luminosity function ( CLF ) modeling .
At these high luminosities ( g < 20.85 quasars ) , the MBII simulation volume ( 100 ~ { } \mathrm { cMpc } / h comoving boxsize ) has only 3 quasar pairs at distances of 1 - 4 Mpc .
The black-hole masses for the pairs range between M _ { bh } \sim 1 - 3 \times 10 ^ { 9 } ~ { } M _ { \odot } / h and the quasar hosts are haloes of M _ { h } \sim 1 - 3 \times 10 ^ { 14 } ~ { } M _ { \odot } / h .
Such pairs show signs of recent major mergers in the MBII simulation .
By modeling the central and satellite AGN CLFs as log-normal and Schechter distributions respectively ( as seen in MBII AGNs ) , we arrive at CLF models which fit the simulation predictions and observed luminosity function and the small-scale clustering measured for the SDSS sample .
The small-scale clustering of our mock quasars is well-explained by central-satellite quasar pairs that reside in M _ { h } > 10 ^ { 14 } ~ { } M _ { \odot } / h dark matter haloes .
For these pairs , satellite quasar luminosity is similar to that of central quasars .
Our CLF models imply a relatively steep increase in the maximum satellite luminosity , L ^ { * } _ { \mathrm { sat } } , in haloes of M _ { h } > 10 ^ { 14 } ~ { } M _ { \odot } / h with associated larger values of L ^ { * } _ { \mathrm { sat } } at higher redshift .
This leads to increase in the satellite fraction that manifests itself in an enhanced clustering signal at \lesssim 1 Mpc/h .
For the ongoing eBOSS-CORE sample , we predict \sim 200 - 500 quasar pairs at z \sim 1.5 ( with M _ { h } \gtrsim 10 ^ { 13 } ~ { } M _ { \odot } / h and M _ { bh } \gtrsim 10 ^ { 8 } ~ { } M _ { \odot } / h ) at \sim 25 ~ { } \mathrm { kpc } scales .
Such a sample would be \gtrsim 10 times larger than current pair samples .