2004/02/06 by D. G. Yakovlev, C. J. Pethick · 16 citations
Physics and Astronomy · #Accretion (finance) #Astrophysical Phenomena and Observations #Astrophysics #Gamma-ray bursts and supernovae #Neutrino #Neutron star #Nuclear physics #Nucleosynthesis #Physics #Pulsars and Gravitational Waves Research #Quark star #Stars #Strange matter #Superfluidity #astro-ph #r-process
paper · pdf · doi:10.1146/annurev.astro.42.053102.134013
published as Ann.Rev.Astron.Astrophys. 42 (2004) 169-210 · 41 pages, 12 figures, to appear in Ann. Rev. Astron. Astrophys., 2004
arxiv created 2004/02/06 · openalex publication_date 2004/08/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
▪ Abstract Observation of cooling neutron stars can potentially provide information about the states of matter at supernuclear densities. We review physical properties important for cooling such as neutrino emission processes and superfluidity in the stellar interior, surface envelopes of light elements owing to accretion of matter, and strong surface magnetic fields. The neutrino processes include the modified Urca process and the direct Urca process for nucleons and exotic states of matter, such as a pion condensate, kaon condensate, or quark matter. The dependence of theoretical cooling curves on physical input and observations of thermal radiation from isolated neutron stars are described. The comparison of observation and theory leads to a unified interpretation in terms of three characteristic types of neutron stars: high-mass stars, which cool primarily by some version of the direct Urca process; low-mass stars, which cool via slower processes; and medium-mass stars, which have an intermediate behavior. The related problem of thermal states of transiently accreting neutron stars with deep crustal burning of accreted matter is discussed in connection with observations of soft X-ray transients. Observations imply that some stars cool more rapidly than can be explained on the basis of nonsuperfluid neutron star models cooling via the modified Urca process, whereas other star cool less rapidly. We describe possible theoretical models that are consistent with observations.