Gravitational waves from massive magnetars formed in binary neutron star mergers

Understand

Binary neutron star (NS) mergers are among the most promising sources of gravitational waves (GWs), as well as candidate progenitors for short Gamma-Ray Bursts (SGRBs).

• Depending on the total initial mass of the system, and the NS equation of state (EOS), the post-merger phase can see a prompt collapse to a black hole, or the formation of a supramassive NS, or even a stable NS.
• In the case of post-merger NS (PMNS) formation, magnetic field amplification during the merger will produce a magnetar with a large induced mass quadrupole moment, and millisecond spin.
• If the timescale for orthogonalization of the magnetic symmetry axis with the spin axis is sufficiently short the NS will radiate its spin down energy primarily via GWs.