Integral Field Spectroscopy Of The Brightest Knots Of Hh 223 In L723

TL;DR

This study uses integral field spectroscopy to map the physical conditions and kinematics of the brightest knots in HH 223, revealing detailed emission and velocity structures that improve upon previous long-slit observations.

Contribution

First application of integral field spectroscopy to HH 223 knots, providing comprehensive 3D kinematic and physical condition maps that outperform traditional long-slit methods.

Findings

IFS maps match narrow-band images in morphology

IFS-derived physical conditions agree with long-slit data at intersected points

IFS reveals discrepancies with long-slit data at shifted positions

Abstract

HH 223 is the optical counterpart of a larger scale H2 outflow, driven by the protostellar source VLA 2A, in L723. Its poorly collimated and rather chaotic morphology suggested the Integral Field Spectroscopy (IFS) as an appropriate option to map the emission for deriving the physical conditions and the kinematics. Here we present new results based on the IFS observations made with the INTEGRAL system at the WHT. The brightest knots of HH 223 (\sim16 arcsec, 0.02 pc at a distance of 300 pc) were mapped with a single pointing in the spectral range 6200-7700 A. We obtained the emission-line intensity maps for Halpha, [NII] 6584 A and [SII] 6716, 6731 A, and explored the distribution of the excitation and electron density from [NII]/Halpha, [SII]/Halpha, and [SII] 6716/6731 line-ratio maps. Maps of the radial velocity field were obtained. We analysed the 3D-kinematics by combining the knot radial velocities, derived from IFS data, with the knot proper motions derived from multi-epoch, narrow-band images. The intensity maps built from IFS data reproduced well the morphology found in the narrow-band images. We checked the results obtained from previous long-slit observations with those derived from IFS spectra extracted with a similar spatial sampling. At the positions intersected by the slit, the physical conditions and kinematics derived from IFS are compatible with those derived from long-slit data. In contrast, significant discrepancies were found when the results from long-slit data were compared with the ones derived from IFS spectra extracted at positions shifted a few arcsec from those intersected by the slit. This clearly revealed IFS observations as the best choice to get a reliable picture of the HH emission properties.