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We have used spectra of 181 projected quasar pairs at separations $\le 1.5$arcmins from the Sloan Digital Sky-Survey Data Release 12 in the redshift rangeof 2.5 to 3.5 to probe the proximity regions of the foreground quasars. Westudy the proximity effect both in the longitudinal as well as in thetransverse directions, by carrying out a comparison of the \lya absorptionlines originating from the vicinity of quasars to those originating from thegeneral inter-galactic medium at the same redshift. We found an enhancement inthe transmitted flux within 4 Mpc to the quasar in the longitudinal direction.However, the trend is found to be reversed in the transverse direction. In thelongitudinal direction, we derived an excess overdensity profile showing anexcess up to $r\leq 5$ Mpc after correcting for the quasar's ionization, takinginto account the effect of low spectral resolution. This excess overdensityprofile matches with the average overdensity profile in the transversedirection without applying any correction for the effect of the quasar'sionization. Among various possible interpretations, we found that theanisotropic obscuration of the quasar's ionization seems to be the mostprobable explanation. This is also supported by the fact that all of ourforeground quasars happen to be Type-I AGNs. Finally, we constrain the averagequasar's illumination along the transverse direction as compared to that alongthe longitudinal direction to be $\leq$27\% (3$\sigma$ confidence level).

Probing the environment of high-z quasars using the proximity effect in projected quasar pairs