More reliable constraints on the microlensing optical depth comes from a better understanding of the Galactic model .
Based on well-constrained Galactic bulge and disk models constructed from survey observations , such as , \it { HST } , 2MASS , and SDSS , we calculate the microlensing optical depths toward the Galactic bulge fields , and compare them with recent results of microlensing surveys .
We test \chi ^ { 2 } statistics of microlensing optical depths expected from those models , as well as previously proposed models , using two types of data : optical depth map in ( l,b ) and averaged optical depth over the Galactic longitude l as a function of the latitude b .
From this analysis , we find that the Galactic bulge models of 2MASS , Han \& Gould ( 2003 ) , and G2 of Stanek et al .
( 1997 ) show a good agreement with the microlensing optical depth profiles for all the microlensing observations , compared with E2 of Stanek et al .
( 1997 ) .
We find , on the other hand , that models involving an SDSS disk model produce relatively higher \chi ^ { 2 } values .
It should be noted that modeled microlensing optical depths diverge in the low Galactic latitude , |b| \lesssim 2 \arcdeg .
Therefore , we suggest the microlensing observation toward much closer to central regions of the Galaxy to further test the proposed Galactic models , if it is more technically feasible than waiting for large data set of microlensing events .