Wolf–Rayet stars, black holes and the first detected gravitational wave source

Abstract

The recently discovered burst of gravitational waves GW150914 provides a good new chance to verify the current view on the evolution of close binary stars. Modern population synthesis codes help to study this evolution from two main sequence stars up to the formation of two final remnant degenerate dwarfs, neutron stars or black holes (Masevich & Tutukov, 1988). To study the evolution of the GW150914 predecessor we use the "Scenario Machine" code presented by Lipunov, Postnov & Prokhorov (1996). The scenario modelling conducted in this study allowed to describe the evolution of systems for which the final stage is a massive BH+BH merger. We find that the initial mass of the primary component can be 100 ÷ 140M ⊙ and the initial separation of the components can be 50 ÷ 350R ⊙ . Our calculations show the plausibility of modern evolutionary scenarios for binary stars and the population synthesis modelling based on it.

Spin of LIGO/VIRGO merging black holes as the result of binary evolution

“…One of them is the stronger stellar winds of massive stars lead to a rapid and substantial increase of the orbital separation, so these stars cannot fill their Roche lobes. There exist several observational facts that argue against scenarios with strong stellar winds (they can be found in Bogomazov et al, 2018), but we make calculations also for scenarios B and C to show that in a wide range of evolutionary parameters the isolated binary evolution can describe all detected gravitational wave bursts. 3 See also (Pavlovskii et al, 2017).…”

“…Antonini et al (2016). Nevertheless, Bogomazov et al (2018) showed that it is possible to produce a massive binary BH (that can merge within an appropriate interval of time) with or without the common envelope phase as the result of the isolated binary evolution.…”

“…Originally scenario C uses this equation without a parameter p m (i.e, ∆M = (M − M core )), but for this work we introduced it to decrease the mass loss rate via the stellar wind, because without such correction it failed to explain the origin of most massive BH mergers (Bogomazov et al, 2018) and the existence of such X-ray binaries as IC 10 X-1 and NGC 300 X-1 (Abubekerov et al, 2009;Bogomazov, 2014). Evolutionary scenarios B and C have several specific properties compared to the classical scenario.…”

The Pair-Instability Mass Gap for Black Holes

“…We consider here a 130 M star finishing its hydrogen burning evolution in a close binary with a black hole of ∼ 60 M with an initial orbital separation of 300 R , or about 2 × 10 13 cm. Such a configuration is reasonable for the progenitors of LIGO sources (Bogomazov et al 2018). The initial black hole mass is reasonable for the range of reaction rates and rotation rates considered in this paper.…”

Scanning Fabry--Perot Interferometer of the 6-m SAO RAS Telescope

“…At the center of the candidate hypernova remnant there is an X-ray source-IC10 X-1-a binary consisting of a WR star and a massive (23-24 M ) black hole. In recent years, interest in such objects has increased due to the detection of gravitational waves from merging black holes (see discussion in Bogomazov et al, 2018).…”