2005/12/09 by Naomi Hirano, Sheng-Yuan Liu, Sheng‐Yuan Liu +9 · 8 citations
Chemistry · Physics and Astronomy · #Astrophysics and Star Formation Studies #Molecular Spectroscopy and Structure #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/500201
published as Astrophys.J.636:L141-L144,2006 · 7 pages, 1 table and 4 figures, Accepted for publication in the ApJL
arxiv created 2005/12/09 · openalex publication_date 2005/12/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We have mapped the SiO J = 5-4 line at 217 GHz from the HH 211 molecular outflow with the Submillimeter Array (SMA). The high-resolution map (1 6 × 0 9) shows that the SiO J = 5-4 emission comes from the central narrow jet along the outflow axis with a width of ~0 8 (~250 AU) FWHM. The SiO jet consists of a chain of knots separated by 3''-4'' (~1000 AU), and most of the SiO knots have counterparts in shocked H 2 emission seen in a new, deep VLT near-infrared image of the outflow. A new, innermost pair of knots have been discovered at just ±2'' from the central star. The line ratio between the SiO J = 5-4 data and the upper limits from the SiO J = 1-0 data of Chandler & Richer suggests that these knots have a temperature in excess of 300-500 K and a density of (0.5-1) × 10 7 cm -3 . The radial velocity measured for these knots is ~30 km s -1 , comparable to the maximum velocity seen in the entire jet. The high temperature, high density, and velocity structure observed in this pair of SiO knots suggest that they are closely related to the primary jet launched close to the protostar.