Abstract
We develop a minimal self-gravitating model for pulsar glitches by introducing a solid-crust potential in the three-dimensional Gross-Pitaevskii-Poisson equation, which we have used earlier to study gravitationally bound Bose-Einstein condensates, i.e., bosonic stars. In the absence of the crust potential, we show that, if we rotate such a bosonic star, it is threaded by vortices. We then show, via extensive direct numerical simulations, that the interaction of these vortices with the crust potential yields (a) stick-slip dynamics and (b) dynamical glitches. We demonstrate that, if enough momentum is transferred to the crust from the bosonic star, then the vortices are expelled from the star, and the crust's angular momentum ${J}_{c}$ exhibits features that may be interpreted as glitches. From the time series of ${J}_{c}$, we compute the cumulative probability distribution functions (CPDFs) of event sizes, event durations, and waiting times, which are consistent with the previous work. We show that these CPDFs have signatures of self-organized criticality, which are similar to those seen in observations of pulsar glitches and are consistent with previous work.
Highlights
Rotating magnetized neutron stars [1,2], or pulsars, display glitches, which are sudden increases in their rotational frequencies
If enough momentum is transferred to the crust from the bosonic star, the vortices are expelled from the star, and the crust’s angular momentum Jc exhibits features that may be interpreted as glitches
We show that these cumulative probability distribution functions (CPDFs) have signatures of self-organized criticality, which are similar to those seen in observations of pulsar glitches and are consistent with previous work
Summary
Rotating magnetized neutron stars [1,2], or pulsars, display glitches, which are sudden increases in their rotational frequencies These observations have a long history [3,4,5], and they indicate that glitches are associated with the transfer of angular momentum, which is carried by quantum vortices in the superfluid interior, to the solid crust, in the outer layers of the pulsar. This transfer occurs because of vortex-crust interactions, as suggested in Refs.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have