The effect of ionizing background fluctuations on the spatial correlations of high redshift Ly$\alpha$-emitting galaxies

We investigate the possible influence of fluctuations in the metagalactic photoionizing ultra-violet background (UVBG) on the clustering of Ly$\alpha$-emitting galaxies through the modulation of the ionization level of the gas surrounding the systems. At redshifts $z>5$, even when assuming the reionization of the intergalactic medium has completed, the fluctuations are sufficiently large that they may non-negligibly enhance, and possibly even dominate, the angular correlation function on scales up to a few hundred arcsecs. Whilst a comparison with observations at $z\sim 5.7$ is statistically consistent with no influence of UVBG fluctuations, allowing for the fluctuations opens up the range of acceptable models to include those with relatively low bias factors for the Ly$\alpha$-emitting galaxies. In this case, the evolution in the bias factor of Ly$\alpha$-emitters over the approximate redshift range $3<z<7$ corresponds to a nearly constant halo mass for Ly$\alpha$-emitting galaxies of $\sim {10}^{10.5}{M}_{\odot }$.