Final Orbits of Neutron Stars: Background Information

Potsdam,10. January 2011

Neutron stars
Neutron stars are the final stage of massive stars that explode as a supernova. In the explosion process, the core of the star collapses to form a compact object with roughly 1.4 solar masses that mostly consists of nuclear matter, predominantly of neutrons.

Cosmic collisions
Collisions of astronomical compact objects such as black holes and neutron stars are among the most powerful events in the universe. Scientists of the numerical relativity group (leader: professor Luciano Rezzolla) at the Max Planck Institute for gravitational physics simulate mergers of black holes and neutron stars, calculate the energy released in these events and comparing it with the one obtained from astronomical observations. In addition, because of their compactness and mass, black holes and neutron stars are the most promising sources of gravitational waves.

Gravitational-wave astronomy
Gravitational waves are a direct prediction of Einstein’s theory of general relativity and represent simple ripples in the fabric of space and time which are produced by large and compact masses when moving at very large velocities. Scientists from all over the world anxiously await for the first direct detection of gravitational waves. With gravitational wave astronomy we will have the possibility to know much of the still unknown 96% of the Universe. By detecting them we will effectively “listen” to the Universe, that is, observe it in a range of frequencies which is very different from the at which we routinely obtain astronomical electromagnetic information. Besides dealing with the enormous experimental difficulties related with the detection of the gravitational-wave signals, the search for gravitational waves requires detailed knowledge of the expected signals and cutting-edge methods for managing huge amounts of data. In the ‘Astrophysical Relativity’ division at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Potsdam-Golm, lead by professor Bernard F. Schutz, both research fields are investigated in internationally leading working groups.