High-sensitivity millimeter imaging of molecular outflows in nine nearby high-mass star-forming regions

Abstract

We present a study of molecular outflows using six molecular lines (including 12CO/13CO/C18O/HCO+(J = 1-0) and SiO/CS(J = 2-1)) toward nine nearby high-mass star-forming regions with accurate known distances. This work is based on the high-sensitivity observations obtained with the 14-m millimeter telescope of Purple Mountain Observatory Delingha (PMODLH) observatory. The detection rate of outflows (including 12CO, 13CO, HCO+, and CS) is 100\%. However, the emission of SiO was not detected for all sources. The full line widths ($\Delta V$) at 3$\sigma$ above the baseline of these molecular lines have the relationship $\Delta V_{{}^{12}\mathrm{CO}}>\Delta V_{\mathrm{HC}{\mathrm{O}}^{+}}>\Delta V_{\mathrm{CS}}\approx \Delta V_{{}^{13}\mathrm{CO}}>\Delta V_{{}^{18}\mathrm{CO}}$. 12CO and HCO+ can be used to trace relatively high-velocity outflows, while 13CO and CS can be employed to trace relatively low-velocity outflows. The dynamical timescales of the 13CO and CS outflows are longer than those of the 12CO and HCO+ outflows. The mechanical luminosities, masses, mass-loss rates and forces of all outflows (including 12CO, 13CO, HCO+, and CS) are correlated with the bolometric luminosities of their central IRAS sources.

35 pages, 17 figures, 9 tables, accepted for publication in ApJS

References in corpus (6)

• Theory of Star Formation
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• The local spiral structure of the Milky Way
• Molecular outflows around high-mass young stellar objects
• Who Is Eating the Outflow?: High-Angular Resolution Study of an Intermediate-Mass Protostar in L1206
• Ammonia and CO Outflow around 6.7 GHz Methanol Masers

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• Neutral Stellar Winds Toward the High-Mass Star-Forming Region G176.51+00.20