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Submillimeter emission from the hot molecular jet HH 211

A. Palau·P. T. P. Ho·Q. Zhang·R. Estalella·N. Hirano·H. Shang·C. -F. Lee·T. L. Bourke·H. Beuther·Y. -J. Kuan
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Abstract

We observed the HH 211 jet in the submillimeter continuum and the CO(3-2) and SiO(8-7) transitions with the Submillimeter Array. The continuum source detected at the center of the outflow shows an elongated morphology, perpendicular to the direction of the outflow axis. The high-velocity emission of both molecules shows a knotty and highly collimated structure. The SiO(8-7) emission at the base of the outflow, close to the driving source, spans a wide range of velocities, from -20 up to 40 km s^{-1}. This suggests that a wide-angle wind may be the driving mechanism of the HH 211 outflow. For distances greater than 5" (1500 AU) from the driving source, emission from both transitions follows a Hubble-law behavior, with SiO(8-7) reaching higher velocities than CO(3-2), and being located upstream of the CO(3-2) knots. This indicates that the SiO(8-7) emission is likely tracing entrained gas very close to the primary jet, while the CO(3-2) is tracing less dense entrained gas. From the SiO(5-4) data of Hirano et al. we find that the SiO(8-7)/SiO(5-4) brightness temperature ratio along the jet decreases for knots far from the driving source. This is consistent with the density decreasing along the jet, from (3-10)x10^6 cm^{-3} at 500 AU to (0.8-4)x10^6 cm^{-3} at 5000 AU from the driving source.

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A. Palau, P. T. P. Ho, Q. Zhang, R. Estalella, N. Hirano, H. Shang, C. -F. Lee, T. L. Bourke, H. Beuther, Y. -J. Kuan. 2005-12-12. Submillimeter emission from the hot molecular jet HH 211. https://doi.org/10.1086/500242

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