Magnetic Field-Decay-Induced Electron Captures: a Strong Heat Source in Magnetar Crusts
Abstract
We propose a new heating mechanism in magnetar crusts. Magnetars' crustal magnetic fields are much stronger than their surface fields; therefore, magnetic pressure partially supports the crust against gravity. The crust loses magnetic pressure support as the field decays and must compensate by increasing the electron degeneracy pressure; the accompanying increase in the electron Fermi energy induces nonequilibrium, exothermic electron captures. The total heat released via field-decay electron captures is comparable to the total magnetic energy in the crust. Thus, field-decay electron captures are an important, if not the primary, mechanism powering magnetars' soft X-ray emission.
Keywords
Cite
@article{arxiv.0910.2466,
title = {Magnetic Field-Decay-Induced Electron Captures: a Strong Heat Source in Magnetar Crusts},
author = {Randall L. Cooper and David L. Kaplan},
journal= {arXiv preprint arXiv:0910.2466},
year = {2015}
}
Comments
4 pages, 2 figures, minor improvements, results and conclusions unchanged; accepted by ApJL