Neutron star physics from short gamma-ray bursts: before, during, and after
Arthur Suvorov, TAT-IAAT — 01.02.2021
The historic dual-detection of gravitational waves and a short gamma-ray burst (SGRB) by LIGO and Fermi/INTEGRAL in 2017 confirmed, amongst other things, that neutron star mergers can be SGRB progenitors. In some rare cases, SGRBs are seen to be preceded by 'precursor flashes' several seconds prior to the merger. These events are likely associated with outbursts from the pre-merging objects, and may therefore be able to teach us something about the properties of cold (< 108 K) and mature stars. The phenomenology of the gravitational waveforms associated with the main burst can also be used to place constraints on the equation of state of neutron star matter. A substantial number of SGRBs are also followed by periods of X-ray afterglow, sometimes even flares, which can be interpreted as persistent energy injections from the newborn object following the merger. One can thus infer information about the behaviour of newborn and hot (> 1010 K) stars from afterglow lightcurves and simulations of jet break-out.
All told, there are three stages to SGRBs from which we might hope to learn something about neutron star behaviour: precursors (before), main events (during), and afterglows (after). In this Talk I summarise some recent research efforts on each of these three stages to give an overview for what we might be able to learn from existing and upcoming X-ray, gamma-ray, and gravitational wave observations.