Time-dependent evolution of the protoplanetary discs with magnetic winds

Abstract

ABSTRACT We study the evolution of the protoplanetary discs (PPDs) in the presence of magnetically driven winds with the stress relations motivated by the non-ideal MHD disc simulations. Contribution of the magnetic winds in the angular momentum removal and mass-loss is described using these relations which are quantified in terms of the plasma parameter. Evolution of the essential disc quantities including the surface density, accretion rate, and wind mass-loss rate are studied for a wide range of the model parameters. Two distinct phases of the disc evolution are found irrespective of the adopted input parameters. While at the early phase of the disc evolution, global disc quantities such as its total mass and magnetic flux undergo non-significant reductions, their rapid declines are found in the second phase of evolution. Duration of each phase, however, depends upon the model parameters including magnetic wind strength. Our model predicts that contributions of the magnetic winds in the disc evolution are significant during the second phase. We then calculated locus of points in the plane of the accretion rate and total disc mass corresponding to an ensemble of evolving PPDs. Our theoretical isochrone tracks exhibit reasonable fits to the observed PPDs in star-forming regions Lupus and σ-Orion.