CFD-MHD Project Research Highlights

Radio Free-Free Emissions from YSO Jets

Hsien Shang, along with collaborators Susana Lizano (UNAM, Morelia), Al Glassgold (UCB), and Frank Shu (NTHU), have achieved producing radio free-free emission maps from YSO jets based on the schematic approach developed by Shang et al. (2002, SGSL02) with the x-winds. They attempted preliminary comparisons and interpretation for the free-free emissions at 3.6 cm where data are best obtained with VLA at high angular resolution. The original SGSL02 models the optical forbidden lines of [S~II] and [O~I] emissions with weak shocks. To extend to the radio regime, with the help of proper scaling of stellar parameters, accretion rates, and x-ray luminosity, Shang et al synthesize radiation maps for radio jets. Excited by the mechanisms of SGSL, the 3.6 cm flux radiated by jets from young stellar objects of mass loss rates ~ 10E-8 Msun/yr or lower may be two orders of magnitude below the VLA detection limit, while sources with mass loss rates close to ~ 10E-6 Msun/yr or higher may predict flux at a comparable level with the radio jets that have been observed at 0.1" resolution at 3.6 cm. This work is currently being prepared for publication as Shang, Lizano, Glassgold and Shu (2003) for the Astrophysical Journal.