Journal article
Mountain formation by repeated, inhomogeneous crustal failure in a neutron star
AD Kerin, A Melatos
Monthly Notices of the Royal Astronomical Society | Published : 2022
Abstract
The elastic crust of a neutron star fractures repeatedly as it spins down electromagnetically. An idealized, macroscopic model of inhomogeneous crustal failure is presented based on a cellular automaton with nearest-neighbour tectonic interactions involving strain redistribution and thermal dissipation. Predictions are made of the size and waiting-time distributions of failure events, as well as the rate of failure as the star spins down. The last failure event typically occurs when the star spins down to ≈ 1 per of its birth frequency with implications for rotational glitch activity. Neutron stars are commonly suggested as sources of continuous gravitational waves. The output of the automat..
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Grants
Awarded by Australian Research Council Centre of Excellence for Gravitational Wave Discovery
Funding Acknowledgements
We thank the anonymous referee for their insightful comments and their substantial and concrete suggestions about how to improve the automaton. Specifically, the referee contributed: (i) the improved energy conserving nearest-neighbour interaction in Section 2.3; (ii) the associated rule in Section 2.4 for neighbouring cells to rise and fall in response to failure, which conserves the average centrifugalgravitational potential energy of the crust; (iii) a clearer description of the interface between the superfluid core and rigid crust; (iv) the inclusion of irreversible heat release as part of the failure process, as discussed in Sections 2.3 and 2.5 and Appendix B; and (v) the decision to evaluate (r i, j,.i, j, fi, j) at the crust-core boundary. This research was supported through the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (grant number CE170100004) and Discovery Project DP170103625. ADK is supported by an Australian Government Research Training Program Scholarship and by the University of Melbourne.