Neutron Star Astrophysics at the Crossroads: Magnetars and the Multimessenger Revolution
Neutron stars are the strongest magnets known in the Universe. With central densities 5-10 times larger than the nuclear density and huge magnetic fields, in the TeraGauss range and above, neutron stars and their extreme manifestations, known as magnetars, provide unique laboratories to probe the properties of matter under conditions that can not be reproduced in ground-based experiments, or met in any other astrophysical environments. Magnetars are the remnants of core-collapse supernovae and binary neutron star mergers, both detectable sources of gravitational waves (GWs) by Advanced LIGO, Virgo and KAGRA.
A new era in the study of neutron stars was ushered in by the ground-breaking discovery of GW170817, the first multi-messenger transient observed through GWs and light. Different messengers provided complementary views of the same source, enabling a leap forward in our knowledge of relativistic jets, cosmic nucleosynthesis, nuclear physics and cosmology. This nascent field is set to soon revolutionize the study of neutron stars, magnetars and their links to the most spectacular cosmic fireworks, such as giant flares, gamma-ray bursts, kilonovae and supernovae.
The symposium will provide an interdisciplinary forum, timely bringing together astrophysicists, computational and nuclear physicists, gravitational wave researchers and others to discuss these new findings and lay down the open questions to be solved in the first decade of multi-messenger astrophysics. It will present the status, perspectives and challenges in the blossoming era of multi-messenger astronomy and it will explore the many facets of magnetars, from theory to their most to extreme observational manifestations, cosmic fireworks, such as giant flares, gamma-ray bursts, kilonovae and supernovae. It will include discussions on next generation facilities for multi-messenger astronomy and their associated science cases.
- Neutron Star Population and Environment: phenomenology of neutron stars and links among different neutron star classes. How are neutron stars created and how do they evolve? How do they form binaries and what are their host galaxies?
- Neutron Stars as Sources of Gravitational Waves: signals expected from isolated neutron star and neutron star in binary systems. Constraints on neutron star physics by multi-wavelength and multi-messenger observations.
- Magnetars: from their formation to present multiwavelength observations. Neutron star magnetic fields, magnetar magnetospheres, and highly-magnetized neutron stars in binary systems. Magnetars as remnant of NS mergers.
- Emission Processes: what is the role of magnetic field in isolated and binary NS multi-wavelength emission? How do the properties of NS binaries (mass, spin, magnetic field) affect thermal and non-thermal emission?
- Relativistic Astrophysics: do all neutron star mergers create relativistic jets? Do magnetars power short gamma-ray bursts and their afterglow?
- Cosmic nucleosynthesis: the role of binary neutron stars and magnetar central engines in the production of heavy elements.
- Future Perspectives: what are the key issues in NS physics to be addressed with future multi-wavelength and multimessenger observatories?