• Citer

Role of the symmetry energy on the neutron-drip transition in accreting and nonaccreting neutron stars

par Fantina, Anthea ;Chamel, Nicolas ;Mutafchieva, Y. D.;Stoyanov, Zh. K.;Mihailov, L.M.;Pavlov, Rossen
Référence Physical review. C, Nuclear physics, 93, page (015801)
Publication Publié, 2016-01-15

Article révisé par les pairs

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

In this paper, we study the role of the symmetry energy on the neutron-drip transition in both nonaccreting and accreting neutron stars, allowing for the presence of a strong magnetic field as in magnetars. The density, pressure, and composition at the neutron-drip threshold are determined using the recent set of the Brussels-Montreal microscopic nuclear mass models, which mainly differ in their predictions for the value of the symmetry energy J and its slope L in infinite homogeneous nuclear matter at saturation. Although some correlations between on the one hand the neutron-drip density, the pressure, the proton fraction, and on the other hand J (or equivalently L) are found, these correlations are radically different in nonaccreting and accreting neutron stars. In particular, the neutron-drip density is found to increase with L in the former case, but decreases in the latter case depending on the composition of ashes from x-ray bursts and superbursts. We have qualitatively explained these different behaviors using a simple mass formula. We have also shown that the details of the nuclear structure may play a more important role than the symmetry energy in accreting neutron-star crusts.