Molecular outflows (seen in the radio) from young stars were discovered in 1981, and "giant" Herbig-Haro flows (seen in the optical) have been recognized as associated with these outflows in just the past few years. The work of Hector Arce and collaborators, described in the publications below, shows that: 1) outflows contain enough momentum and energy to drive MHD turbulence in a large fraction of a molecular cloud's volume; 2) outflows are highly episodic; and 3) a model of outflows that involves prompt entrainment of gas at the head of (an episodic) jet provides the best fit to observations.
- Goodman, A. A. & Arce, H. G. 2004, PV Ceph: Young Star Caught Speeding?,
ApJ, 608, 831., presented at AAS Press Conference on 1/5/04
Arce & Goodman 2001, The Episodic, Precessing Giant Molecular Outflow from IRAS 04239+2436 (HH 300)
Arce & Goodman 2001, The Mass-Velocity and Position-Velocity Relations in Episodic Outflows