A New Milky Way Concordance

We describe a new graphical concordance of catalogs of extended objects in the Milky Way, which is useful for making cross-catalog comparisons and for identifying otherwise unknown objects. The catalogs included cover Galactic H II regions, reflection nebulae, dark clouds, planetary nebulae, supernova remnants, and the NGC 2000. The concordance is interactive and uses the SuperMongo plotting package. Besides source positions, the concordance gives information about source sizes and distances, when they are available. It is thus complementary to other text-based catalog information services. It can easily be extended to treat more catalogs than the 15 currently available.