On the viability of the magnetorotational instability in circumplanetary disks

Journal Article · Sun Apr 20 04:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/785/2/101· OSTI ID:22357110

Fujii, Yuri I.; Okuzumi, Satoshi; Inutsuka, Shu-ichiro ^[1]; Tanigawa, Takayuki ^[2]

---

1. Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan)
2. Institute of Low Temperature Science, Hokkaido University, Sapporo 066-0819 (Japan)

We examine whether the magnetorotational instability (MRI) can serve as a mechanism of angular momentum transport in circumplanetary disks. For the MRI to operate the ionization degree must be sufficiently high and the magnetic pressure must be sufficiently lower than the gas pressure. We calculate the spatial distribution of the ionization degree and search for the MRI-active region where the two criteria are met. We find that there can be thin active layers at the disk surface depending on the model parameters, however, we find hardly any region which can sustain well-developed MRI turbulence; when the magnetic field is enhanced by MRI turbulence at the disk surface layer, a magnetically dominated atmosphere encroaches on a lower altitude and a region of well-developed MRI turbulence becomes smaller. We conclude that if there are no angular momentum transfer mechanisms other than MRI in gravitationally stable circumplanetary disks, gas is likely to pile up until disks become gravitationally unstable, and massive disks may survive for a long time.

• OSTI ID: 22357110
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 785; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALTITUDE
ANGULAR MOMENTUM
ANGULAR MOMENTUM TRANSFER
ATMOSPHERES
DUSTS
INSTABILITY
LAYERS
MAGNETIC FIELDS
NMR IMAGING
PLANETS
PROTOPLANETS
SATELLITES
SPATIAL DISTRIBUTION
SURFACES
TURBULENCE
VIABILITY