The evolution of GRS 1915+105—an X-ray binary with a black hole

A brief review of the observed parameters of binary systems with black holes is presented. We discuss in detail the evolutionary status of the X-ray binary GRS 1915+105, which contains a massive black hole. Numerical simulations of the evolution of GRS 1915+105 at the X-ray stage indicate that the most probable initial mass of the optical component (donor star) is (1.5–)M⊙. Two possible scenarios are suggested for the evolution of the system prior to the formation of the black hole. If the initial mass of the optical component was (2.5–)M⊙, the system underwent a common-envelope phase; in this case, the initial mass of the black hole progenitor did not exceed ∼50M⊙. If the initial mass of the donor was (1.5–2.5)M⊙, a scenario without a common envelope is possible, with the initial mass of the black hole progenitor being smaller than ∼50M⊙. The lack of information about the initial mass-ratio distribution for binary components for small q and the uncertainty of the system parameters make it impossible to give preference to a particular scenario for the system's prior evolution.