Long-term Evolution of Protostellar and Protoplanetary Disks. I. Outbursts
Abstract
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 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. We also confirm quasi-steady accretion behavior for high mass infall rates if the values of α-parameter for the MRI are small, while at this high accretion rate convection from the thermal instability may lead to some variations. We further constrain the combinations of the α-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 companion paper, we will explore both long-term outburst and disk evolution with this model, allowing for infall from protostellar envelopes with differing angular momenta
Additional Information
© 2010 American Astronomical Society. Received 2009 November 14; accepted 2010 February 24; published 2010 March 31. This work was supported in part by NASA grant NNX08A139G, by the University of Michigan, by a Sony Faculty Fellowship, a Richard and Margaret Romano Professorial Scholarship, and a University Scholar appointment to Charles Gammie.Attached Files
Published - Zhu2010p9921Astrophys_J.pdf
Files
Name | Size | Download all |
---|---|---|
md5:0ae3027e559c4c54f8bb9b455403d011
|
584.6 kB | Preview Download |
Additional details
- Eprint ID
- 18351
- Resolver ID
- CaltechAUTHORS:20100519-114213558
- NNX08A139G
- NASA
- University of Michigan
- Sony Faculty Fellowship
- Richard and Margaret Romano Professorial Scholaship
- Created
-
2010-05-20Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field