Two-dimensional simulations of fu orionis disk outbursts

Zhaohuan Zhu, Lee Hartmann, Charles Gammie, Jonathan C. McKinney

Research output: Contribution to journalArticlepeer-review


We have developed time-dependent models of FU Ori accretion outbursts to explore the physical properties of protostellar disks. Our two-dimensional, axisymmetric models incorporate full vertical structure with a new treatment of the radiative boundary condition for the disk photosphere. We find that FU Ori-type outbursts can be explained by a slow accumulation of matter due to gravitational instability. Eventually, this triggers the magnetorotational instability, which leads to rapid accretion. The thermal instability is triggered in the inner disk, but this instability is not necessary for the outburst. An accurate disk vertical structure, including convection, is important for understanding the outburst behavior. Large convective eddies develop at the transition region between the thermal instability high-low states in the inner disk. The models are in agreement with Spitzer IRS spectra and also with peak accretion rates and decay timescales of observed outbursts, though some objects show faster rise timescale. We also propose that convection may account for the observed mild-supersonic turbulence and the short-timescale variations of FU Orionis objects.

Original languageEnglish (US)
Pages (from-to)620-634
Number of pages15
JournalAstrophysical Journal
Issue number1
StatePublished - 2009


  • Accretion, accretion disks
  • Circumstellar matter
  • Convection
  • Stars: formation
  • Stars: pre-main sequence
  • Stars: variables: other

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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