“Entangled” pairs of stars disrupted by the tidal action of Super Massive Black Hole

Abstract

Based on modern observations on central S-stars by Gillessen et al. and hypervelocity stars (HVS) by Brown et al. the question is raised whether it is possible to establish the genetic duality of these stars? Could they belong in the past to a common parent binary star until it was captured and then gravitationally ruptured by a supermassive black hole (SMBH) within the Hills scenario? A cross-analysis of these observational data is carried out to obtain reliable evidence for the possible quantitative relationship of the stars under consideration. Three key issues are considered: 1. reconstruction of the trajectory of HVS ejection from the SMBH neighborhood by the method of backward integration in the Galaxy potential; 2. estimation of the dynamical stability of the S-star orbits by the \(N\)-body method — direct integration of their motion in the central field of the SMBH, taking into account the perturbing potential created by the S-cloud members; 3. checking of the coplanarity of orbits of a central S-star and an HVS; For nine HVSs it is possible to reconstruct the central trajectory of the ejection (at a distance less than a parsec from the SMBH) within the uncertainty of the observational proper motion values. For S2 star the timescale of the dynamical stability of its spatial orbital configuration in the S-cloud is evaluated as ∼ 100,000 years. This requires an additional comment on the criterion of the coplanarity of the orbits of paired S-HVS. The problem of identifying tidally decoupled components (S-HVS pairs) by the SMBH field poses a challenge to modern astrometric observations, and not only. This problem may provide an independent test of our knowledge of the distribution of baryon and dark matter, as well as the Galactic gravitational potential constructed on their basis, which is important in cosmological and evolutionary interpretations.