Images of HCO(+) (1-0) emission in a molecular cloud near 1E 1740.7 - 2942

Abstract

We have observed the hard X-ray source 1E 1740.7 - 2942 in the HCO(+) (1-0) line using the Owens Valley millimeter interferometer. Previous single-dish observations have found HCO(+) emission coincident with the location of the radio continuum hot spots of the radio source associated with 1E 1740.7 - 2942. Our higher resolution observations show a 15 sec offset between the HCO(+) emission and the location of the radio hot spots. We propose that the lack of emission results from a large ionization rate, exceeding 10-15/s, in the neighborhood of 1E 1740.7 - 2942.