Plasma effects in the Lacey-Ostriker model of the Galactic rotation curveD.D. RyutovLivermore, CA 94550, USA

One of the models of the “missing mass” needed to match the observed rotation curve assumes the presence of a quasi-isotropic cloud of black holes overlapping with the gaseous halo of our galaxy and creating the additional gravitational pull [1]. The black holes barreling through the gas with the virial velocity ~250 km/s create significant density and temperature perturbations. We study these perturbations at distances well beyond the Schwarzschild radius and up to a few parsecs (pc). A characteristic “tail” appears here, with higher density, temperature, and ionization degree. Near the tail axis, a zone of fast interpenetrating flows is formed; collisionless shocks appear here via the Weibel instability and produce significant electron acceleration [2]. We parametrize spatial features of the hot substance in terms of the average mass of the black holes between 10 and 300 solar masses and relate them to the observational data [3].

1. 1. C.G. Lacey, J.P. Ostriker. ApJ, 299, 633 (1985).
   
   2. F. Fiuza et al. Nature Physics, 16, 916 (2020).
   
   3. M.E. Putman et al. Ann. Rev. Astron. Astrophys, 50, 491 (2012).