# Studying newborn neutron stars by the transient emission after stellar collapses and compact binary mergers

## TL;DR

This paper explores how newborn neutron stars formed from stellar collapses and mergers produce various luminous transients, including supernovae, optical transients, and gamma-ray bursts, driven by their magnetic fields and rotation.

## Contribution

It provides a comprehensive analysis of the transient emissions associated with newborn neutron stars and their potential to generate diverse astrophysical phenomena.

## Key findings

- Newborn NSs can produce super-luminous supernovae via spin-down energy.
- Unusual luminous optical transients may originate from NS mergers and white dwarf collapses.
- Relativistic jets and gamma-ray bursts can be launched if magnetic fields are sufficiently amplified.

## Abstract

The formation of neutron stars (NSs), both from collapses of massive stars and mergers of compact objects, can be usually indicated by bright transients emitted from explosively-ejected material. In particular, if the newborn NSs can rotate at a millisecond period and have a sufficiently high magnetic field, then the spin-down of the NSs would provide a remarkable amount of energy to the emitting material. As a result, super-luminous supernovae could be produced in the massive stellar collapse cases, while some unusual fast evolving and luminous optical transients could arise from the cases of NS mergers and accretion-induced collapses of white dwarfs. In all cases, if the dipolar magnetic fields of the newborn NSs can be amplified to be as high as $10^{15}$ G, a relativistic jet could be launched and then a gamma-ray burst can be produced as the jet successfully breaks out from the surrounding nearly-isotropic ejected material.