Models for Interstellar Extinction in the Galaxy

摘要: We present two models for the interstellar extinction in Galaxy that are based on hypothesis dust is well mixed with gas, a constant ratio (except small dependence of metallicity Galactic radius), and therefore proportional to column density gas. In first model we assume axisymmetric; gas disk function radius distance perpendicular plane, second take into account spiral structure Galaxy. this case, instead increasing almost linearly distance, increases by steps each time arm crossed, but only slowly interarm regions. The distribution obtained from Berkeley Parkes H I surveys Columbia University CO survey. IRAS 100 μm brightness also used as tracer density. predictions compared data taken number catalogs color excess distances large samples stars. Our useful estimating objects corrections which can be estimated some other method, star counts Galaxy, among applications.