Implications of gravitational wave detections for stellar astrophysics

Lida Oskinova, University of Potsdam - 02.07.18

Abstract:

Stars with masses much higher than our Sun end their short lives in a gravitational collapse, leaving behind neutron stars and black holes. The first detections of gravitational waves (GW) brought massive star astrophysics into the new multi-messenger era. In the decades to come, GW observatories will routinely measure the masses, distances, and spins of merging massive star remnants. At the same time, conventional observations will discover electromagnetic echos of massive core collapses and compact object mergers, the supernovae and gamma-ray bursts. When a massive binary evolves, one component will collapse first. In case the newly formed compact object remains bound, it may accrete matter lost by its non-degenerate companion and thus power strong X-ray radiation. The resulting high-mass X-ray binaries (HMXBs) bridge the evolutionary gap between massive stars and GW sources, and are intensively studied by modern X- and gamma-ray telescopes. A comprehensive understanding of massive star lives and deaths is urgently required to fully unleash the power of multi-messenger astronomy. In this talk I will briefly review what we presently know about massive stars, and highlight the key problems in our current understanding of neutron star and black hole progenitors. I will further discuss the potential of HMXBs to constrain the evolutionary channels leading to GW events. Finally, I will discuss what the recent GW observations already have told us about massive stars, and how the different scenarios for the GW progenitors could be tested by massive star astrophysics.