Thermal conductivity of neutrons in neutron star cores

¹ A.F. Ioffe Physical Technical Institute, Politekhnicheskaya 26, 194021 St. Petersburg, Russia
² N. Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw, Poland
³ Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA

Corresponding author: P. Haensel, haensel@camk.edu.pl

Received: 3 January 2001
Accepted: 27 April 2001

Abstract

The diffusive thermal conductivity of neutrons in dense matter [ g cm^-3] of neutron star cores is calculated. The contribution from neutron-neutron and neutron-proton collisions is taken into account. We use the transition probabilities calculated for symmetric dense nucleon matter on the basis of the Dirac-Brueckner approach to the in-medium effects and the Bonn model of bare nucleon-nucleon interaction. The diffusive thermal conductivity of neutrons in the presence of neutron and proton superfluidities is analyzed in a microscopic manner; the effects of superfluidity are shown to be significant. The low temperature behavior of the thermal conductivity appears to be extremely sensitive to the relation between critical temperatures of neutrons and protons. The results are fitted by simple analytic expressions. In combination with the formulae for the electron and muon thermal conductivities, obtained earlier, the present expressions provide a realistic description of the full diffusive thermal conductivity in the neutron star cores for normal and various superfluid phases.