Gemini-IFU spectroscopy of HH 111

TL;DR

This paper presents detailed optical integral field spectroscopy of the HH 111 jet, revealing a layered structure with varying excitation, velocity, and density, enhancing understanding of jet shock dynamics.

Contribution

The study provides the first detailed spatially-resolved optical spectroscopic maps of HH 111, uncovering the jet's internal excitation and velocity structure with high spatial resolution.

Findings

Inner jet region has lower excitation and higher velocity.

Outer sheath exhibits higher excitation and lower velocity.

Higher electron densities are found at lower radial velocities.

Abstract

We present new optical observations of the HH 111 Herbig-Haro jet using the Gemini Multi Object Spectrograph in its Integral Field Unit mode. Eight fields of 5" x 3.5" have been positioned along and across the HH 111 jet, covering the spatial region from knot E to L in HH 111 (namely, knots E, F, G, H, J, K and L). We present images and velocity channel maps for the [O I] 6300+6360, Halpha, [N II] 6548+6583 and [S II] 6716+6730 lines, as well as for the [S II]6716/6730 line ratio. We find that the HH 111 jet has an inner region with lower excitation and higher radial velocity, surrounded by a broader region of higher excitation and lower radial velocity. Also, we find higher electron densities at lower radial velocities. These results imply that the HH 111 jet has a fast, axial region with lower velocity shocks surrounded by a lower velocity sheath with higher velocity shocks.