The Three-Dimensional Structure of HH 32 from GMOS IFU Spectroscopy

Abstract

We present new high-resolution spectroscopic observations of the Herbig-Haro object HH 32 from system verification observations made with the GMOS IFU at Gemini North Observatory. The three-dimensional spectral data cover a 8B7 ? 5B85 spatial field and 4820–7040 A ˚ spectral region centered on the HH 32 A knot complex. We show the position-dependent line profiles and radial velocity channel maps of the H? line, as well as line ratio velocity channel maps of [O iii] k5007/H?,[O i] k6300/H?,[N ii] k6583/H?,[S ii] kk(6716+6730)/H?,and [S ii] k6716/k6730.We find that the line emission and the line ratios vary significantly on spatial scales of ?100 and over velocities of ?50 km s?1. A ‘‘3/2-dimensional’’ bow shock model is qualitatively successful at reproducing the general features of the radial velocity channel maps, but it does not show the same complexity as the data, and it fails to reproduce the line ratios in our high spatial resolutionmaps. The observations ofHH32Ashowtwo or three superposed bow shocks with separations of ?300,which we interpret as evidence of a line-of-sight superposition of two or threeworking surfaces located along the redshifted body of theHH32 outflow.