Gravitational instability in a plasma in a magnetic field. (2) Effects of finite resistivity

Effects of finite resistivity, η, on gravitational instability are investigated in magnetohydrodynamical approximation. It is shown that resistivity has a stabilizing effect on this instability. Main approximations used are: (1) small resistivity, v/L² ≪ ω₀, where v=c² η/4π, L=|B/▽B|≡L_B or |ρ/▽ρ|≡Lρ, and ω₀² = g(1/L_B + 1/L_ρ); (2) strong magnetic field, ω_A≫ω₀ and P≪B²/8π where ω_A is Alfven frequency. Two cases are examined where plasma is partially ionized (v∞ 1/ρ) and fully ionized (v∞ T -3/2). (author)