The two-stream instability in infinite homogeneous and uniformly rotating stellar systems

Abstract

view Abstract Citations (24) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Two-Stream Instability in Infinite Homogeneous and Uniformly Rotating Stellar Systems Araki, Suguru Abstract There is no two-stream instability in infinite homogeneous self-gravitating stellar systems with Maxwellian velocity distributions, although it does occur for suitable non-Maxwellian streams. In more realistic models, the effects of finite size and rotation must be taken into account. The stability analysis is extended to finite, disk-like systems. By comparing the stability diagram of a counterstreaming disk with that of a reference single-stream disk, the two-stream instability can be separated from the Jeans instability inherent in any self-gravitating system. There is a very little parameter space in which a counterstreaming Kalnajs (1972) disk can exhibit the two-stream instability for any mode except (n,m) = (3,1). Using a WKB dispersion relation, the asymptotic behavior of high-order modes in the stability diagram is examined and it is found that the results agree with those from numerical analysis of the exact dispersion relation. Studying the modes for which the two-stream instability is possible, it is likely that the two-stream instability sets in through a neutral mode. Publication: The Astronomical Journal Pub Date: July 1987 DOI: 10.1086/114451 Bibcode: 1987AJ.....94...99A Keywords: Computational Astrophysics; Dynamic Stability; Stellar Rotation; Stellar Systems; Jeans Theory; Phase-Space Integral; Stellar Gravitation; Velocity Distribution; Astrophysics; STARS: STELLAR STATISTICS full text sources ADS |