Heating in the Accreted Neutron Star Ocean: Implications for Superburst Ignition

By Sanjib S. Gupta, Edward F. Brown, Hendrik Schatz, P. Möller, K. Kratz. 2006

157 citations recorded by the source corpus.

We perform a self-consistent calculation of the thermal structure in the crust of a superbursting neutron star. In particular, we follow the nucleosynthetic evolution of an accreted fluid element from its deposition into the atmosphere down to a depth where the electron Fermi energy is 20 MeV. We include temperature-dependent continuum electron capture rates and realistic sources of heat loss by thermal neutrino emission from the crust and core. We show that, in contrast to previous calculations, electron captures to excited states and subsequent γ-emission significantly reduce the local heat loss due to weak-interaction neutrinos. Depending on the initial composition, these reactions release up to a factor of 10 times more heat at densities < 1011 g cm-3 than obtained previously. This heating reduces the ignition depth of superbursts. In particular, it reduces the discrepancy noted by Cumming et al. between the temperatures needed for unstable 12C ignition on timescales consistent with observations and the reduction in crust temperature from Cooper pair neutrino emission.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/1755b0de742a3c7075bce2c42af8970adcc42964

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. S. Guillot
2. J. Zdunik
3. R. Rutledge
4. P. Haensel
5. N. Webb
6. Mathieu Servillat
7. J. Lattimer
8. A. Potekhin

In Nuclear and High Energy Physics

1. R. Rutledge
2. J. Zdunik
3. P. Haensel
4. S. Guillot

Citations in the corpus

• MEASUREMENT OF THE RADIUS OF NEUTRON STARS WITH HIGH SIGNAL-TO-NOISE QUIESCENT LOW-MASS X-RAY BINARIES IN GLOBULAR CLUSTERS (2012, background): “In the theory of deep crustal heating (DCH), the matter accreted during an outburst releases ∼ 1.9MeV of energy via pressure-sensitive reactions: electron captures, neutron emissions or pycnonuclear reactions (Sato 1979; Haensel & Zdunik 1990; Gupta et al. 2007; Haensel & Zdunik 2008).”
• Models of crustal heating in accreting neutron stars (2007, methodology): “Generally, viewing the simplicity of the HZ* model, its agreement with the multicomponent, self-consistent calculations of Gupta et al. (2007) is very good.”