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Reverse Shocks in the Relativistic Outflows of Gravitational Wave Detected Neutron Star Binary Mergers
journal contribution
posted on 2019-09-09, 16:04 authored by Gavin P. Lamb, Shiho KobayashiThe afterglows to gamma-ray bursts (GRBs) are due to synchrotron emission from
shocks generated as an ultra-relativistic outflow decelerates. A forward and a reverse
shock will form, however, where emission from the forward shock is well studied as a
potential counterpart to gravitational wave-detected neutron star mergers the reverse
shock has been neglected. Here, we show how the reverse shock contributes to the
afterglow from an off-axis and structured outflow. The off-axis reverse shock will appear as a brightening feature in the rising afterglow at radio frequencies. For bursts at
∼ 100 Mpc, the system should be inclined . 20◦
for the reverse shock to be observable
at ∼ 0.1 − 10 days post-merger. For structured outflows, enhancement of the reverse
shock emission by a strong magnetic field within the outflow is required for the emission to dominate the afterglow at early times. Early radio photometry of the afterglow
could reveal the presence of a strong magnetic field associated with the central engine.
Funding
GPL is supported by STFC grant ST/S000453/1.
History
Citation
Monthly Notices of the Royal Astronomical Society, 489, 1820–1827 (2019)Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and AstronomyVersion
- VoR (Version of Record)