Extinction in the Galaxy from surface brightnesses of ESO-LV galaxies: testing 'standard' extinction maps

Abstract

The relative extinction in the Galaxy computed with our new method (Choloniewski and Valentijn 2003, CV) is compared with three patterns: Schlegel, Finkbeiner and Davis (1998, SFD), Burstein and Heiles (1978, BH) and the cosecans law. It is shown that extinction of SFD is more reliable then that of BH since it stronger correlates with our new extinction. The smallest correlation coeffcient have been obtained for the cosecans law. Linear regression analysis show that SFD overestimate the extinction by a factor of 1.4. Our results clearly indicate that there is non-zero extinction at the Galactic South pole and that the extinction near the Galactic equator ($|b|<40^o$) is significantly larger in the Southern hemisphere than in the Northern.