PaperPanorama

Nuclear Theory·nucl-th

Friday·November 21, 2025

3 papers1 primary·2 cross-listed

  1. 02

    Post-Supernova Accretion of Light Elements onto a New-Born Neutron Star and NS 1987A

    Natalia de Jesús Baz-Pérez · Dany Page · Simon Guichandut · Martin Nava-Callejas · Yuri Cavecchi · Andrew Cumming

    We model early accretion of light elements, He, C, and O, onto a new-born neutron star using the public stellar evolution code MESA, simulating what may happen during the first few years of its life. We find that, under the appropriate conditions, significant amounts of these elements can be accreted up to densities of 10^9 g/cc without triggering a nuclear explosion that would convert them into heavy elements. These results help to understand observations that favor light elements in the atmospheres of young cooling neutron stars, as the one found in the supernova remnant Cassiopeia A, and also add support to the recent indications for the presence of a neutron star, NS 1987A, in the remnant of SN 1987A.

    astro-ph.SRastro-ph.HEnucl-thMNRAS(2026)·0 citations
  2. 03

    Neutron star heating vs. HST observations

    Luis E. Rodríguez🇨🇱 · Andreas Reisenegger🇨🇱 · Denis González-Caniulef🇫🇷 · Cristóbal Petrovich🇨🇱 · George Pavlov🇺🇸 · Sébastien Guillot🇫🇷 · Oleg Kargaltsev🇺🇸 · Blagoy Rangelov🇺🇸

    Passively cooling neutron stars (NSs) should reach undetectably low surface temperatures K in less than yr. However, HST observations have revealed likely thermal UV emission from the Gyr-old millisecond pulsars PSR~J04374715 and PSR~J21243358, and from the yr-old classical pulsars PSR~B095008 and PSR~J01081431, implying K and the need for heating mechanisms. We compute the thermal evolution of these NSs including rotochemical heating (RH) in the core with normal or Cooper-paired matter, vortex creep (VC) in the inner crust, and crustal heating through nuclear reactions, and compare the results with observations and with the upper limit for PSR~21443933. No single mechanism explains all sources. The high temperature of PSR~J04374715 can be reproduced by RH with a large Cooper pairing gap MeV for either neutrons or protons, but this requires an unrealistically short initial period ms to activate the same mechanism in PSR~B095008. Conversely, the latter can be explained by RH with modified Urca reactions in normal matter or by VC with an excess angular momentum erg,s, but these models underpredict PSR~J04374715. A model combining RH with a large pairing gap and VC matches both pulsars and is consistent with the upper limits for the remaining three. It further predicts that their temperatures should lie close to these limits, suggesting that deeper or broader-wavelength observations would provide a strong test of this scenario.

    astro-ph.HEastro-ph.SRnucl-thAstron.Astrophys.(2026)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE