Clustering of Ly-alpha emitters around luminous quasars at z = 2-3: an
  alternative probe of reionization on galaxy formation
  Narrowband observations have detected no Ly-alpha emission within a 70 pMpc^3
volume centered on the z = 2.168 quasar PKS 0424-131. This is in contrast to
surveys of Ly-alpha emitters in the field at similar redshifts and flux limits,
which indicate that tens of sources should be visible within the same volume.
The observed difference indicates that the quasar environment has a significant
influence on the observed density of Ly-alpha emitters. To quantify this effect
we have constructed a semi-analytic model to simulate the effect of a luminous
quasar on nearby Ly-alpha emitters. We find the null detection around PKS
0424-131 implies that the minimum isothermal temperature of Ly-alpha emitter
host halos is greater than 3.4 x 10^6 K (68% level), corresponding to a virial
mass of ~1.2 x 10^12 M_solar. This indicates that the intense UV emission of
the quasar may be suppressing the star formation in nearby galaxies. Our study
illustrates that low redshift quasar environments may serve as a surrogate for
studying the radiative suppression of galaxy formation during the epoch of
reionization.
