Multi-Messenger Tests for Fast-Spinning Newborn Pulsars Embedded in Stripped-Envelope Supernovae

TL;DR

This paper explores how fast-spinning, highly magnetized newborn neutron stars can power various types of stripped-envelope supernovae, and discusses multi-messenger signals like X-rays, gamma rays, and gravitational waves to identify such pulsar-driven explosions.

Contribution

It models the energy injection from magnetized winds and Ni decay in newborn neutron stars, linking their properties to different supernova types and proposing observational signatures for detection.

Findings

Proto-neutron stars with >10 ms rotation and B_dip > 5 x 10^14 G can power ordinary supernovae Ibc.

Millisecond proto-neutron stars with strong magnetic fields can produce superluminous supernovae Ic.

Detectable gravitational waves from non-axisymmetric proto-neutron stars are possible in the Virgo cluster.

Abstract

Fast-spinning strongly magnetized newborn neutron stars, including nascent magnetars, are popularly implemented as the engine of luminous stellar explosions. Here, we consider the scenario that they power various stripped-envelope supernovae, not only super-luminous supernovae Ic but also broad-line supernovae Ibc and possibly some ordinary supernovae Ibc. This scenario is also motivated by the hypothesis that Galactic magnetars largely originate from fast-spinning neutron stars as remnants of stripped-envelope supernovae. By consistently modeling the energy injection from magnetized wind and Ni decay, we show that proto-neutron stars with >~ 10 ms rotation and B_dip >~ 5 x 10^14 G can be harbored in ordinary supernovae Ibc. On the other hand, millisecond proto-neuton stars can solely power broad-line supernovae Ibc if they are born with poloidal magnetic field of B_dip >~ 5 x 10^14 G, and superluminous supernovae Ic with B_dip >~ 10^13 G. Then, we study how multi-messenger emission can be used to discriminate such pulsar-driven supernova models from other competitive scenarios. First, high-energy x-ray and gamma-ray emission from embryonic pulsar wind nebulae is a promising smoking gun of the underlying newborn pulsar wind. Follow-up observations of stripped-envelope supernovae using NuSTAR ~ 50-100 days after the explosion is strongly encouraged for nearby objects. We also discuss possible effects of gravitational-waves on the spin-down of proto-neutron stars. If millisecond proto-neutron stars with B_dip <~ a few x 10^13 G emit gravitational waves through e.g., non-axisymmetric rotation deformed by the inner toroidal fields of B_t >~ 10^16 G, the gravitational wave signal can be detectable from ordinary supernova Ibc in the Virgo cluster by Advanced LIGO, Advanced Virgo, and KAGRA.