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Description
Neutron star glitches may be caused by the sudden unpinning and collective movement of vortices in the superfluid condensate inside the star, also known as vortex avalanches. The metastable vortex configuration between avalanches is determined by the far-from-equilibrium avalanche dynamics and is nonaxisymmetric in general, producing a small but nonzero current quadrupole moment which generates persistent, quasi-monochromatic gravitational waves as it rotates. In this work, we use an N-body simulation of vortex avalanches to calculate an empirical scaling of this current quadrupole, and extrapolate that scaling to estimate the characteristic wave strain for this mode of emission. We also develop analytic upper- and lower-bound characteristic wave strain, which corresponds to idealized regimes in vortex dynamics and bracket the empirical scaling.