Influence of dark matter on gravitational stability of isothermal gas clouds

ABSTRACT To date, the presence of dark matter (DM) can be judged only by its gravitational interaction on the visible matter. It is therefore important to find the consequences of this interaction, which can then help to determine both the DM properties and parameters and the dynamics and evolution of visible matter. The gravitational influence of dark matter on the stability of interstellar medium (ISM), the progenitor of stars and star clusters, was considered. An isothermal self-gravity gas was taken as a suitable model describing ISM, particles interacting only gravitationally were considered as DM. The results obtained by analytical methods show that even a small amount of fast DM particles significantly increases the stable radius of the gas cloud and the corresponding mass while a higher relative density of DM destabilizes the gas. It was shown that with typical parameters of ISM and DM, its presence increases the maximum stable mass of isothermal cloud by a factor of 4 and the radius by five.