AMMONIA EMISSION DOWNSTREAM OF THE HERBIG-HARO OBJECT .1.

We report VLA D-configuration NH3(1, 1) and (2, 2) observations of Her big-Haro Object 1 (HH 1). In direct analogy to the case of HH 2 (Torre lles et al. 1992b), we have found ammonia emission immediately adjacen t to and downstream of HH 1. As in the case of HH 2, there is no evide nce of any significant perturbation in terms of heating and broadening of the ammonia lines. This high degree of symmetry between the HH 1 a nd HH 2 ammonia clumps implies a causal physical relationship between the HH objects and the ammonia emission, discarding the possibility th at these clumps are just ambient clumps projected by chance downstream of the HH objects. In particular, we think that there is the possibil ity that these clumps delineate nearby ambient gas whose ammonia emiss ion is enhanced by some still unknown process related to the radiation field generated at the head of the jet of the VLA-1 source. However, detailed theoretical calculations will be needed to investigate this p ossibility. We also detected two other clumps located to -the southwes t of HH 1. One of them, seen only in the (2, 2) line, coincides with a n H2O maser, and its temperature (greater than or similar to 30 K) sug gests that there might be a young star embedded in this clump. The oth er clump is located approximately 15'' south of the H2O maser. We also detected ammonia emission from the previously reported condensation a ssociated with VLA-1 (Rodriguez et al. 1990a). As it was also previous ly reported, this condensation consists of two halves with a velocity shift of approximately 2 km s-1 of the same direction and sign as thos e of the HH 1-2 optical outflow. However, on dynamical considerations, we argue that this shift could represent expanding or contracting mot ions of a flattened structure seen almost edge-on, rather than a molec ular outflow of low collimation.