This talk focuses on how short duration Gamma-Ray Bursts (GRBs) signaled the dawn of multi-messenger astronomy through the watershed event GW170817/GRB170817A, and finishes by briefly outlining recent progress in our understanding of the possible roles of internal shocks in GRB prompt gamma-ray emission:
1. The first detection of a gravitational wave signal from a binary neutron star merger, GW 170817, was accompanied by an electromagnetic counterpart in the form of the short duration GRB 170817A (prompt gamma-rays, kilonova and afterglow). This unique event has wide-ranging implications, from constraining the neutron star equation of state and maximal mass, through the important role of such compact binary mergers in r-process nucleosynthesis in the universe, to the type of remnant that was produced, and the properties of the outflows launched by such mergers.
I will outline what it has taught us about the physics of the relativistic jets that power short GRBs, the constraints on the type of compact remnant (black hole or massive neutron star) that was left in its aftermath and nuclear density equation of state, as well as how this and other short GRBs can be used to constrain the propagation speed of gravity waves, the extragalactic background light, or possible violations of Lorentz invariance.
2. Internal shocks within the relativistic outflow are a leading dissipation process for powering the prompt gamma-ray emission in GRBs. I will outline how their improved, realistic hydrodynamic modeling leads to new spectral and temporal signatures that may help explain some of the observed prompt GRB properties.