Onset of electron captures and shallow heating in magnetars

<p>The loss of magnetic pressure accompanying the decay of the magnetic field in a magnetar may trigger exothermic electron captures by nuclei in the shallow layers of the outer crust. The threshold density and pressure, as well as the maximum amount of heat that can be possibly released were calculated for different nuclei. The Landau-Rabi quantization of electron motion was taken into account using approximate analytical formulas. Results were obtained using experimental atomic masses and the&nbsp;<span class="math-tex">\(Q_\beta\)</span> values (included recommended ones) from the <a href="http://amdc.in2p3.fr/web/masseval.html">2016 Atomic Mass Evaluation</a> supplemented with the atomic mass model <a href="https://link.aps.org/doi/10.1103/PhysRevC.88.024308">HFB-24</a> available on the <a href="http://www.astro.ulb.ac.be/bruslib/">BRUSLIB</a> database.</p> <p>Each file contains data for electron captures by nuclei with the specified charge number Z and mass number A. The columns are as follows:&nbsp;</p> <ul> <li>magnetic field strengh in units of <span class="math-tex">\(B_{\rm rel}=\dfrac{m_e^2 c^3}{e \hbar}\approx 4.41\times 10^{13}\, \rm G\)</span></li> <li>the pressure in dyn cm^-2</li> <li>the mass density in g cm^-3</li> <li>the heat per nucleon in MeV.</li> </ul> <p>The files with (without) label &#39;ex&#39; contain results for ground state to excited state (ground state) transitions.</p>