ACCRETION DISKS IN TWO-DIMENSIONAL HOYLE-LYTTLETON FLOW

Journal Article · Sat Apr 20 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/2/135· OSTI ID:22126925

We investigate the flip-flop instability observed in two-dimensional planar hydrodynamic simulations of Hoyle-Lyttleton accretion in the case of an accreting object with a radius much smaller than the nominal accretion radius, as one would expect in astrophysically relevant situations. Contrary to previous results with larger accretors, accretion from a homogenous medium onto a small accretor is characterized by a robust, quasi-Keplerian accretion disk. For gas with a ratio of specific heats of 5/3, such a disk remains locked in one direction for a uniform ambient medium. The accretion flow is more variable for gas with a ratio of specific heats of 4/3, with more dynamical interaction of the disk flow with the bow shock leading to occasional flips in the direction of rotation of the accretion disk. In both cases the accretion of angular momentum is determined by the flow pattern behind the accretion shock rather than by the parameters of the upstream flow.

• OSTI ID: 22126925
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 767; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
ANGULAR MOMENTUM
ASTROPHYSICS
HYDRODYNAMICS
INSTABILITY
INTERACTIONS
ROTATION
SHOCK WAVES
SIMULATION
SPECIFIC HEAT
TWO-DIMENSIONAL CALCULATIONS
X RADIATION