Year: 2025
Type: article
Abstract: The cooling strength of the Urca pair, 63Fe–63Mn, exhibits an extensive range of variation due to the uncertainty in the spin parity of the ground state of 63Fe. To investigate the cooling effect of this Urca pair on the thermal evolution of neutron star crusts, we performed simulations on neutron star structure and evolution under various spin-parity assignment scenarios. When adopting recently evaluated nuclear data, 63Fe–63Mn emerges as one of the strongest Urca pairs. In the case of MAXI J0556-332, 63Fe–63Mn is the only pair above the shallow heating layer, significantly impacting the cooling curve and the superburst ignition. Moreover, the constraint on the past nucleosynthesis reduced to one-quarter of its original value, falling within three decades, which enables the validation of nuclear reaction theories in the outer layers of neutron stars. Our results highlight the need for more precise measurements of the β − decay of 63Mn to better determine the Urca cooling effect of the 63Fe–63Mn pair in accreted neutron star crusts.
Source: The Astrophysical Journal
Authors: Hao Huang, Kuoang Li, Zhong Liu, Xiaodong Tang, Peng Shuai, Zach Meisel
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W4413436110