Abstract
An aperture synthesis mapping study of the 6 cm absorption line of H2CO and of the continuum of NGC 2024 has been carried out, and the results are reported. The new data show details of the H II region and molecular gas which were not previously known and, together with the published data, allow the formulation of a more comprehensive and accurate model of the region. This model involves a bubble blown in the molecular cloud by a newly formed star or stars. The principal ionizing star is probably near the peak of the southern compact H II region and the unresolved ionization front at the southern edge of the radio continuum map. Photons from this star penetrate the dense molecular gas to the south, producing both strong extended infrared emission just south of the ionization front and strong carbon recombination line emission. The optical depth of the 6 cm H2CO, together with 2 cm H2CO line data, is used to estimate the average H2 density. Photon trapping corrections for the H2(C-12)O/H2(C-13)O ratio are estimated from these data. (C.D.)