Extinction Map of Baade's Window

Recently Wo'zniak & Stanek (1996) proposed a new method to investigate interstellar extinction, based on two band photometry, which uses red clump stars as a means to construct the reddening curve. I apply this method to the color-magnitude diagrams obtained by the Optical Gravitational Lensing Experiment (OGLE) to construct an extinction map of $({40}^{\mathrm{\prime }}{)}^2$ region of Baade’s Window, with resolution of $\sim 30arcsec$. Such a map should be useful for studies of this frequently observed region of the Galactic bulge. The map and software useful for its applications are available via {\tt anonymous ftp}. The total extinction $A_V$ varies from $1.26mag$ to $2.79mag$ within the $({40}^{\mathrm{\prime }}{)}^2$ field of view centered on $(\alpha_{2000}, \delta_{2000}) =$(18:03:20.9,--30:02:06),i\mathrm{.}e\mathrm{.}$(l,b)=(1.001,-3.885)$. The ratio $A_V\mathrm{/}E(V-I)=2.49\pm 0.02$ is determined with this new method.