Neutrino transport and hydrodynamic stability of rotating proto-neutron stars

Abstract

Aims. We study the stability of differentially rotating, non-magnetic proto-neutron stars. Methods. The stability is considered by making use of a linear analysis and taking neutrino transport into account. Results. When neutrino transport is efficient, the star can be subject to a diffusive instability that can occur even in the convectively stable region. The instability arises on a time scale that is comparable to the time scale of thermal diffusion. Hydrodynamic motions driven by the instability can lead to anisotropy in the neutrino flux since the instability is suppressed near the equator and rotation axis.

Magnetorotational instability in proto-neutron stars

“…The analogy of the GSF dissipative instability can occur in both magnetic and non-magnetic PNSs. In non-magnetic stars, this instability arises if the angular velocity depends on the vertical coordinate z (Urpin 2007), and the shellular rotation is a particular case of such rotation. Since neutrino transport in PNSs is much more efficient than radiative transport in ordinary stars, the dissipative instability can be rather fast.…”