Abstract
We present low resolution, infrared spectroscopic observations (1.2-2.4 j#m) near two optical condensations (A & G) of the leading working surface of Herbig-Haro object 1, in order to study the nature of their molecular shocks. Condensation A spectra show several molecular hydrogen lines, besides the strong (1,0) 5(1) 2.121 m and (2,1) 5(1) 2.247 j#m lines, as well as [Fe II] 1.257 j#m and [Fe II] 1.644 j#m. Condensation G does not show 112 lines, but its [Fe II] lines are as strong as those in A. We compare the 112 column densities of 11111-A, with those predicted by J-type and C-type shock modds. It is difficult to distinguish between these models given our observations. From the [Fe II] lines we estimate an extinction of Av = 6.7 + 1.4 magnitudes (or an E(B-V) of 2.2 i 0.4 magnitudes), which it is higher than what it is obtained from the [S II] lines measurements.
