Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-03-08
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
Accepted to publish in ApJ
Scientific paper
As an initial investigation into the long-term evolution of protostellar disks, we explore the conditions required to explain the large outbursts of disk accretion seen in some young stellar objects. We use one-dimensional time-dependent disk models with a phenomenological treatment of the magnetorotational instability (MRI) and gravitational torques to follow disk evolution over long timescales. Comparison with our previous two-dimensional disk model calculations (Zhu et al. 2009b, Z2009b) indicates that the neglect of radial effects and two-dimensional disk structure in the one-dimensional case makes only modest differences in the results; this allows us to use the simpler models to explore parameter space efficiently. We find that the mass infall rates typically estimated for low-mass protostars generally result in AU-scale disk accretion outbursts, as predicted by our previous analysis (Zhu et al. 2009a,Z2009a). We also confirm quasi-steady accretion behavior for high mass infall rates if the values of $\alpha$-parameter for the magnetorotational instability is small, while at this high accretion rate convection from the thermal instability may lead to some variations. We further constrain the combinations of the $\alpha$-parameter and the MRI critical temperature, which can reproduce observed outburst behavior. Our results suggest that dust sublimation may be connected with full activation of the MRI. This is consistent with the idea that small dust captures ions and electrons to suppress the MRI. In a later paper we will explore both long-term outburst and disk evolution with this model, allowing for infall from protostellar envelopes with differing angular momenta.
Book Laura G.
Engelhard Eric
Gammie Charles F.
Hartmann Lee
Simon Jacob B.
No associations
LandOfFree
Long-term Evolution of Protostellar and Protoplanetary Disks. I. Outbursts does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Long-term Evolution of Protostellar and Protoplanetary Disks. I. Outbursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Long-term Evolution of Protostellar and Protoplanetary Disks. I. Outbursts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-454220