P13 an ULX that is a potential progenitor of merging BH-NS system

الأصل · EN

We have studied the future evolution of a recently discovered ULX source P13 in NGC7793. This source was shown to contain a 5-15M black hole and a massive 18-23M B9Ia companion on a 64 day orbit. For low black hole mass (5-10M) and high companion mass 20 M the binary is predicted to initiate a common envelope evolution in near future and significantly decrease the orbital separation (6 hr orbit). This leads to a high probability (70%) of the system surviving a supernova explosion that will form a neutron star out of the companion. About one third of the surviving BH-NS systems will merge within Hubble time and be a source of high frequency gravitational radiation. We estimate that the chances of detection of BH-NS systems with advanced LIGO/Virgo that form via P13-evolutionary channel are at the level of 0.1 yr⁻¹ with wide range of allowed probability 0 ÷0.6yr⁻¹. This is the fourth empirical estimate of BH-NS merger rate.