SIMBAD references

2016MNRAS.457.3430P - Mon. Not. R. Astron. Soc., 457, 3430-3447 (2016/April-3)

Dynamical evolution of star-forming regions - II. Basic kinematics.


Abstract (from CDS):

We follow the dynamical evolution of young star-forming regions with a wide range of initial conditions and examine how the radial velocity dispersion, σ, evolves over time. We compare this velocity dispersion to the theoretically expected value for the velocity dispersion if a region were in virial equilibrium, σvir and thus assess the virial state (σ/σvir) of these systems. We find that in regions that are initially subvirial, or in global virial equilibrium but subvirial on local scales, the system relaxes to virial equilibrium within several million years, or roughly 25-50 crossing times, according to the measured virial ratio. However, the measured velocity dispersion, σ, appears to be a bad diagnostic of the current virial state of these systems as it suggests that they become supervirial when compared to the velocity dispersion estimated from the virial mass, σvir. We suggest that this discrepancy is caused by the fact that the regions are never fully relaxed, and that the early non-equilibrium evolution is imprinted in the one-dimensional velocity dispersion at these early epochs. If measured early enough (

Abstract Copyright: © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): methods: numerical - stars: formation - stars: kinematics and dynamics - open clusters and associations: general

Simbad objects: 7

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