NEUTRINO EMISSION FROM COOPER PAIRS AND MINIMAL COOLING OF NEUTRON STARS

By D. Page, J. Lattimer, M. Prakash, A. Steiner. 2009

164 citations recorded by the source corpus.

The minimal cooling paradigm for neutron star cooling assumes that enhanced cooling due to neutrino emission from any direct Urca process, due either to nucleons or to exotica such as hyperons, Bose condensates, or deconfined quarks, does not occur. Previous studies showed that the observed temperatures of young, cooling, isolated neutron stars with ages between 102 and 105 yr, with the possible exception of the pulsar in the supernova remnant CTA 1, are consistent with predictions of the minimal cooling paradigm as long as the neutron 3P2 pairing gap present in the stellar core is of moderate size. Recently, it has been found that Cooper-pair neutrino emission from the vector channel is suppressed by a large factor, of the order of 10−3, compared to the original estimates that violated vector current conservation. We show that Cooper-pair neutrino emission remains, nevertheless, an efficient cooling mechanism through the axial channel. As a result, the elimination of neutrino emission from Cooper-paired nucleons through the vector channel has only minor effects on the long-term cooling of neutron stars within the minimal cooling paradigm. We further quantify precisely the effect of the size of the neutron 3P2 gap and demonstrate that consistency between observations and the minimal cooling paradigm requires that the critical temperature Tc for this gap covers a range of values between Tminc ≲ 0.2 × 109 up to Tmaxc ≳ 0.5 × 109 in the core of the star. This range of values guarantees that the Cooper-pair neutrino emission is operating efficiently in stars with ages between 103 to 105 yr, leading to the coldest predicted temperatures for young neutron stars. In addition, it is required that young neutron stars have heterogeneous envelope compositions: some must have light-element compositions and others must have heavy-element compositions. Unless these two conditions are fulfilled, about half of the observed young cooling neutron stars are inconsistent with the minimal cooling paradigm and provide evidence for the existence of enhanced cooling.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/8515161ca33326d181f64608a3ee7cc284f2e0e3

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In Astronomy and Astrophysics

1. J. Lattimer
2. A. Steiner
3. C. Heinke
4. José A. Pons
5. W. Ho
6. D. Yakovlev
7. D. Aguilera
8. R. Perna

In Instrumentation

1. J. Lattimer
2. A. Steiner
3. C. Heinke

Citations in the corpus

• Unifying the observational diversity of isolated neutron stars via magneto-thermal evolution models. (2013, methodology): “Page et al. (2004, 2009) proposed the socalled minimal cooling scenario, in which all the necessary known microphysical ingredients are consistently included (specific heat, conductivities, effects of superfluidity, neutrino emission processes), but fast neutrino-cooling processes (direct URCA by…”
• Superfluidity in nuclear systems and neutron stars (2018, background): “Although at low temperatures the PBF processes are again suppressed exponentially, they are very effective in cooling neutron stars at temperatures not far below the critical temperature Tc of a relevant nucleonic condensate [390, 391].”
• THE EQUATION OF STATE FROM OBSERVED MASSES AND RADII OF NEUTRON STARS (2010, background): “…neutron star crust, which controls the crust cooling of transiently accreting LMXBs (Shternin et al. 2007; Brown & Cumming 2009) as well as the distribution of observed cooling curves compared to a minimal cooling model (e.g., Page et al. 2009), could also constrain neutron star masses and radii.”
• Cooling neutron star in the Cassiopeia A supernova remnant: evidence for superfluidity in the core (2010, methodology): “…all isolated NSs. Similar models of NSs withnucleon cores, where direct Urca is forbidden but CPF operates, w re used as the basis of the minimal cooling theory (Page et al. 2004, 2006, 2009) although that theory employs selectedTc(ρ) profiles, most favorable by the theory of nucleon superfluidity.”