Ricard Aguilera Miret: Turbulent magnetic field amplification in BNS mergers

Thursday 23 Feb 2023, 13:00 → 14:00 Europe/Stockholm

A5:1003 (AlbaNova Main Building)

The detection of a binary neutron star merger in 2017 through both
 gravitational waves and electromagnetic emission opened a new era of
 multimessenger astronomy. During the merger, several mechanisms like the
 Kelvin-Helmholtz instability, the winding up effect and the MRI, can
 amplify the initial magnetic field in the remnant to be powerful enoguh
 for launching a jet, with an associated short GRB. When performing
 simulations, simplified assumptions arise for the initial magnetic field
 strength and topology of the merging neutron stars. Here I will show
 convergent results by using high-resolution, large-eddy simulations of
 binary neutron star mergers, following the newly formed remnant for up
 to 30 milliseconds. I will specifically compare simulations with
 different initial magnetic field strenghts and configurations, going
 beyond the widespread-used aligned dipole confined within each star. I
 will show that the magnetic field is always amplified up to ~10^16 G in
 the bulk region of the remnant, while the initial topology is quickly
 forgotten in a timescale of few miliseconds after the merger due to the
 Kelvin-Helmholtz instability.