Work

The impact of nuclear equations of state on the dynamics and multi-messenger emission of magnetorotational stellar explosions

Year: 2026

Type: article

Abstract: Context. The gravitational collapse of massive stars at the end of their lives leads to powerful supernova explosions that produce new stellar-sized compact objects, regulate the dynamics of their host galaxies, and produce new heavy elements that contribute to cosmic chemical evolution. In the presence of fast rotation and strong magnetic fields, such explosions reach extremely high energies that can explain sources such as hypernovae and long gamma-ray bursts, which are the most violent transients observable in the Universe. Aims. We tested the impact of variations in the uncertain nuclear equation of state (EoS) on the dynamics of magnetorotational explosions and the resulting multi-messenger emission, including neutrinos and gravitational waves. In particular, differences in the stiffness, composition, and finite-temperature behavior of the EoS can significantly affect the collapse, bounce, and jet-launching phases. Methods. We used the Aenus-Alcar code, employing relativistic magnetohydrodynamics, two-moment neutrino transport, neutrino-matter interactions, and general-relativistic corrections, to simulate axisymmetric models using different EoSs. All simulations start from the same initial condition, using a standard pre-supernova model with solar metallicity and a zero-age main-sequence mass of 20 M ⊙ endowed with a dipolar magnetic field configuration and a shellular rotation profile. Results. Variations in the stiffness, nuclear interactions, and treatment of nuclei among the different EoSs lead to significant differences in the explosion dynamics, especially in the bounce time, the proto-neutron star properties, the mass of the ejected material, and the associated multi-messenger signals. Conclusions. Our results demonstrate that the multimessenger signatures of magnetorotational core-collapse supernovae (CCSNe) are sensitive to not only the cold stiffness of the EoS but also its thermal and compositional properties. These findings highlight the importance of combining gravitational-wave and neutrino observations to constrain the microphysics of dense matter and the explosion mechanism of rapidly rotating CCSNe.

Source: Astronomy and Astrophysics

DOI: 10.1051/0004-6361/202558662

Authors: A. Celati, M. Bugli, L. Del Zanna, M. Cusinato, M. Obergaulinger