Simulations of Evolving or Outbursting Molecular Protostellar Jets

Abstract

The kinematic and radiative power of molecular jets is expected to change as a protostar undergoes permanent or episodal changes in the rate at which it accretes. We study here the consequences of evolving jet power on the spatial and velocity structure, as well as the fluxes, of molecular emission from the bipolar outflow. We consider a jet of rapidly increasing density and a jet in which the mass input is abruptly cut off. We perform three dimensional hydrodynamic simulations with atomic and molecular cooling and chemistry. In this work, highly collimated and sheared jets are assumed. We find that position-velocity diagrams, velocity-channel maps and the relative H${}_2$ and CO fluxes are potentially the best indicators of the evolutionary stage. In particular, the velocity width of the CO lines may prove most reliable although the often-quoted mass-velocity power-law index is probably not. We demonstrate how the relative H${}_2$ 1--0 S(1) and CO J=1--0 fluxes evolve and apply this to interpret the phase of several outflows.

13 pages, 15 figures, Accepted for publication in MNRAS

References in corpus (3)

• IRAS 21391+5802: The Molecular Outflow and its Exciting Source
• Rarefaction Shocks, Shock Errors and Low Order of Accuracy in ZEUS
• The mass-velocity and intensity-velocity relations in jet-driven molecular outflows

Cited by in corpus (4)

• Outflow Driven Cavities: Numerical Simulations of Intermediaries of Protostellar Turbulence
• Hydrodynamic simulations of molecular outflows driven by slow-precessing protostellar jets
• A study of the wiggle morphology of HH 211 through numerical simulations
• H${}_2$ mass-velocity relationship from 3D numerical simulations of jet-driven molecular outflows