Radio continuum and recombination line observations of the polypolar planetary nebula NGC 2440

H92 alpha and He92 alpha recombination lines and lambda 3.6 cm continuum ob servations have been carried out with the Very Large Array (synthesized bea m 6."8 x 4."2, PA 74 degrees) toward the polypolar planetary nebula NGC 244 0. The H92 alpha and He92 alpha lines have been detected, for the first tim e in this nebula, over a region of theta similar or equal to 14" around its geometric center. The lambda 3.6 cm continuum emission is detected over a region of similar or equal to 65" x 40", similar in extent to the optical e mission. Physical parameters of the nebula have been derived for the region in which the recombination lines were detected. From the line to continuum ratio, an electron temperature of similar or equal to 16,000 K and a singl e ionized helium abundance Y+ similar or equal to 0.14 are obtained. A rela tive extinction map of NGC 2440 has also been obtained from the ratio of th e lambda 3.6 cm continuum acid Ha images. A higher relative extinction in t he central region traces the dense and dusty environment of an apparent cen tral "toroid." The velocity field obtained from the H92a line suggests that the central toroidal structure has a distorted, noncircular shape. The pol ypolar characteristics of this nebula are discussed and compared with those of similar objects.