AI 中文总结
本研究首次将Δ直接Urca过程的中微子发射率纳入中子星冷却模拟，发现该过程可加速中子星冷却，为解释低温中子星提供了新依据。
AI 中文摘要
中子星（NS）的冷却过程可为研究其组成与物态方程提供线索，但该现象的完整认知仍为开放问题。中子星冷却的早期阶段由核心的中微子发射主导，该过程会快速冷却星体；Urca过程是中微子从核心逃逸并带走大部分热量的机制之一，核子与超子直接Urca过程是已知的快速冷却机制。致密物质中Δ重子的可能出现引入了额外的弱相互作用道，包括Δ直接Urca过程。尽管已有研究讨论过Δ混杂中子星物质中的此类过程，但其中微子发射率及对中子星冷却的影响尚未被系统研究。本研究首次将相关Δ直接Urca过程的中微子发射率纳入中子星冷却模拟，探究Δ混杂中子星的热演化并评估这些额外中微子发射道对其冷却行为的影响。研究发现，Δ直接Urca过程可作为高效的中微子冷却机制，显著加速中子星的热演化；结果表明，Δ重子及其相关弱相互作用过程在解释具有异常低表面温度的中子星方面可发挥重要作用，为致密物质组成与中子星冷却观测之间建立了新的关联。
英文摘要
The cooling of neutron stars (NSs) provides insight into their composition and equation of state. However, a complete understanding of this phenomenon is still an open question. The early stage of NS cooling is dominated by neutrino emission from the core, which rapidly cools the star. Urca processes are one such mechanism where neutrinos escape from the core, carrying away most of the heat. Nucleonic and hyperonic direct Urca processes are known rapid cooling mechanisms. The possible appearance of $Δ$ baryons in dense matter introduces additional weak-interaction channels, including $Δ$ direct Urca processes. Although such processes have been discussed in the context of $Δ$-admixed NS matter, their neutrino emissivities and impact on NS cooling have not been systematically investigated. In this work, for the first time we incorporate the neutrino emissivities of the relevant $Δ$ direct Urca processes into NS cooling simulations. We investigate the thermal evolution of $Δ$-admixed NSs and assess the impact of these additional neutrino emission channels on their cooling behavior. We find that $Δ$ direct Urca processes can provide an efficient neutrino-cooling mechanism and significantly accelerate the thermal evolution of NSs. Our results demonstrate that $Δ$ baryons and their associated weak-interaction processes can play an important role in explaining NSs with unusually low surface temperatures and provide a new connection between the composition of dense matter and NS cooling observations.
Comments13 Pages, 3 figures
