{"title":"Nuclear Data to Quantify Urca Cooling in Accreting Neutron Stars","authors":"Rahul Jain","doi":"arxiv-2406.02634","DOIUrl":null,"url":null,"abstract":"Neutron stars in Low Mass X-ray Binaries (LMXBs) can accrete matter onto\ntheir surface from the companion star. Transiently accreting neutron stars go\nthrough alternating phases of active accretion outbursts and quiescence. X-ray\nobservations during the quiescence phase show a drop in X-ray luminosity with\nthe time in quiescence. This is also inferred as the drop in surface\ntemperature or the cooling of accreting neutron stars in quiescence. Analyzing\nthese cooling curves reveals a great deal of information about the structure\nand composition of neutron stars. However, model-observation comparisons of\nsuch cooling curves are challenging - partly due to observational\nuncertainties, and partly due to incomplete knowledge of heating mechanisms\nduring accretion outbursts. This situation is further exacerbated by the recent\ndiscovery of Urca cooling in the neutron star crust. These are cycles that\nalternate between electron-capture and beta-decay to produce a large flux of\nneutrinos and anti-neutrinos. These freely stream out of the star and carry\nenergy with them, essentially cooling the neutron star crust without changing\nthe composition. As a result, it is necessary to accurately quantify the\nstrength of Urca cooling to constrain the heat sources in neutron star crusts\nand facilitate better model-observation comparisons of the cooling curves.","PeriodicalId":501206,"journal":{"name":"arXiv - PHYS - Nuclear Experiment","volume":"237 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Nuclear Experiment","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2406.02634","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Neutron stars in Low Mass X-ray Binaries (LMXBs) can accrete matter onto
their surface from the companion star. Transiently accreting neutron stars go
through alternating phases of active accretion outbursts and quiescence. X-ray
observations during the quiescence phase show a drop in X-ray luminosity with
the time in quiescence. This is also inferred as the drop in surface
temperature or the cooling of accreting neutron stars in quiescence. Analyzing
these cooling curves reveals a great deal of information about the structure
and composition of neutron stars. However, model-observation comparisons of
such cooling curves are challenging - partly due to observational
uncertainties, and partly due to incomplete knowledge of heating mechanisms
during accretion outbursts. This situation is further exacerbated by the recent
discovery of Urca cooling in the neutron star crust. These are cycles that
alternate between electron-capture and beta-decay to produce a large flux of
neutrinos and anti-neutrinos. These freely stream out of the star and carry
energy with them, essentially cooling the neutron star crust without changing
the composition. As a result, it is necessary to accurately quantify the
strength of Urca cooling to constrain the heat sources in neutron star crusts
and facilitate better model-observation comparisons of the cooling curves.
低质量X射线双星(LMXB)中的中子星可以从伴星表面吸积物质。瞬态吸积中子星会经历活跃的吸积爆发和静止交替阶段。静止阶段的 X 射线观测显示,X 射线光度随着静止时间的延长而下降。这也被推断为表面温度的下降或增殖中子星在静止期的冷却。分析这些冷却曲线可以揭示有关中子星结构和组成的大量信息。然而,对这些冷却曲线进行模型-观测比较是一项挑战--部分原因是观测的不确定性,部分原因是对吸积爆发时的加热机制了解不全面。最近在中子星外壳中发现的乌卡冷却现象进一步加剧了这种状况。这些循环在电子捕获和β衰变之间交替进行,产生大量中微子和反中微子。这些中微子自由流出中子星,并携带能量,实质上冷却了中子星外壳,而不改变其成分。因此,有必要精确地量化乌卡冷却的强度,以限制中子星外壳的热源,并便于更好地对冷却曲线进行模型-观测比较。