All-sky search for continuous gravitational waves from neutron stars in binary systems

Gravitational waves from compact binary coalescences are now routinely detected, but other types of gravitational waves await to be discovered.

Rotating neutron stars with an asymmetry around their rotating axis give rise to continuous waves, which differ from the already detected gravitational waves in their long duration (present during the whole observing runs) and expected weaker amplitude. Although many searches for continuous waves have been carried out, no detection has been achieved yet.

The first detection of a continuous wave could be the next major discovery in gravitational-wave astronomy, probing the behaviour of matter at extreme conditions and the equation of state at densities above nuclear density that cannot be reached in any laboratory, the geometrical shape of neutron stars, and fundamental physics with tests of general relativity.This action aims to make the first detection of a continuous wave signal, searching for signals from unknown neutron stars in binary systems.

More than half of the known neutron stars in the sensitive frequency region of the gravitational-wave detectors are part of binary systems.

Neutron stars in binary systems may be more likely to have the asymmetries needed to emit detectable continuous waves, since they might be accreting matter from their companions which provides a natural asymmetry.

This increases the chances of detecting a continuous wave signal, making all-sky searches of continuous waves from binary systems one of the most promising scenarios.All-sky surveys for continuous wave signals from neutron stars in binary systems are probably the most challenging search in gravitational-wave science.

For this reason, they have been carried out seldom and at lower sensitivity compared to surveys from signals from isolated neutron stars, and with this project we want to address this deficiency. This project will be carried out at the Albert Einstein Institute in Hannover, within the research group lead by M.A.

Papa.