Clustering of quasars in SDSS-IV eBOSS : study of potential systematics
  and bias determination
  We study the first year of the eBOSS quasar sample in the redshift range
$0.9<z<2.2$ which includes 68,772 homogeneously selected quasars. We show that
the main source of systematics in the evaluation of the correlation function
arises from inhomogeneities in the quasar target selection, particularly
related to the extinction and depth of the imaging data used for targeting. We
propose a weighting scheme that mitigates these systematics. We measure the
quasar correlation function and provide the most accurate measurement to date
of the quasar bias in this redshift range, $b_Q = 2.45 \pm 0.05$ at $\bar
z=1.55$, together with its evolution with redshift. We use this information to
determine the minimum mass of the halo hosting the quasars and the
characteristic halo mass, which we find to be both independent of redshift
within statistical error. Using a recently-measured quasar-luminosity-function
we also determine the quasar duty cycle. The size of this first year sample is
insufficient to detect any luminosity dependence to quasar clustering and this
issue should be further studied with the final $\sim$500,000 eBOSS quasar
sample.
