Affine algebras, N = 2 superconformal algebras, and gauged WZNW models

We find a canonical N = 2 superconformal algebra (SCA) in the BRST complex associated to any affine Lie algebra ̌ with semisimple. In contrast with the similar known results for the Virasoro, N = 1 supervirasoro, and W₃ algebras, this SCA does not depend on the particular "matter" representation chosen. Therefore it follows that every gauged WZNW model with data (g{script} ⊃ , k) has an N = 2 SCA with central charge c = 3 dim : independent of the level k. In particular, this associates to every embedding sl(2) ⊃ g{script} a one-parameter family of c = 9 N = 2 supervirasoro algebras. As a by-product of the construction, one can deduce a new set of "master equations" for generalized N = 2 supervirasoro constructions which is simpler than the one considered thus far.