James Miller-Jones (ICRAR/Curtin)

James Miller-Jones Colloquium: Cygnus X-1

Kensington Lecture Theatre/Online

Abstract

Title: Inefficient stellar winds from a massive black hole progenitor in the X-ray binary system Cygnus X-1

Abstract: The high-mass X-ray binary system Cygnus X-1 contains one of the first known and best-studied black holes. We recently refined the distance to the source using astrometric very long baseline interferometry observations. The new distance implied that the component masses needed to be revised upwards, with our modelling showing that the system hosts a 21-solar mass black hole. The formation of such a massive black hole in a Galactic environment with roughly solar metallicity challenges existing model prescriptions for the wind mass loss rates from massive stars. I will discuss our new measurements and their consequences for the likely formation and subsequent evolutionary pathway of the black hole, and touch on their implications for massive star evolution and the formation of gravitational-wave sources.