ABSTRACT
Ultra-stripped supernovae are different from other terminal explosions of massive stars, as they show little or no ejecta from the actual supernova event1,2. They are thought to occur in massive binary systems after the exploding star has lost its surface through interactions with its companion2. Such supernovae produce little to no kick, leading to the formation of a neutron star without loss of the binary companion, which itself may also evolve into another neutron star2. Here we show that a recently discovered high-mass X-ray binary, CPD -29 2176 (CD -29 5159; SGR 0755-2933)3-6, has an evolutionary history that shows the neutron star component formed during an ultra-stripped supernova. The binary has orbital elements that are similar both in period and in eccentricity to 1 of 14 Be X-ray binaries that have known orbital periods and eccentricities7. The identification of the progenitors systems for ultra-stripped supernovae is necessary as their evolution pathways lead to the formation of binary neutron star systems. Binary neutron stars, such as the system that produced the kilonova GW170817 that was observed with both electromagnetic and gravitational energy8, are known to produce a large quantity of heavy elements9,10.
ABSTRACT
The discovery of gravity waves from the mergers of black hole binaries has focused the astronomical community on the high mass X-ray binaries (HMXBs) as the potential progenitors of close pairs of compact stars. This symposium gathered experts in observational and theoretical work for a very timely review of our understanding of the processes that drive the X-ray luminosity of the diverse kinds of binaries and what evolutionary stages are revealed in the observed cases. Here I offer a condensed summary of some of the results about massive star properties, the observational categories of HMXBs, their accretion processes, their numbers in the Milky Way and other galaxies, and how they may be related to the compact binaries that merge in a burst of gravity waves.