Shedding Light on the Ejection History of Molecular Outflows: Multiple Velocity Modes and Precession
Abstract
Variable accretion has been well studied in the evolved stages of low-mass star formation. However, the accretion history in the initial phases of star formation is still a seldom studied topic. The outflows and jets emerging from protostellar objects could shed some light on their accretion history. We consider the recently studied case of W43-MM1, a protocluster containing 46 outflows driven by 27 protostellar cores. The outflow kinematics of the individual cores and associated knots in W43-MM1 indicate episodic protostellar ejection. We take the observed parameters of an individual core system (core #8) and perform 3D hydrodynamic simulations of such a system, including episodic changes in the velocity of the outflow. The simulations consist of a collimated jet emerging from a core, taking into account one- and two-velocity modes in the variation of the ejection velocity of the jet. In addition, we investigated the effect of including the precession of the jet in the one- and two-velocity-mode models. From the simulations, we constructed position–velocity diagrams and compared them with the observations. We find that including a second mode in the ejection velocity, as well as the precession, are required to explain the positions of the outflow knots and other position–velocity features observed in core #8 in W43-MM1.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2024
- DOI:
- 10.3847/1538-4357/ad13ed
- arXiv:
- arXiv:2312.13087
- Bibcode:
- 2024ApJ...962...66L
- Keywords:
-
- Stellar jets;
- Massive stars;
- Hydrodynamical simulations;
- 1607;
- 732;
- 767;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 13 pages, 8 figures. Accepted for publication in ApJ