Gravitational Waves from Spinning Neutron Stars

This paper gives an introductory overview of the search for continuous gravitational waves from spinning neutron stars. We review the current theoretical understanding of possible emission mechanisms and the expected strength of signals received on Earth. Given the substantial uncertainties involved in neutron star physics, these searches — if sufficiently sensitive — can provide important new information and constraints about neutron star physics even in the absence of detection. We describe the challenging detection problem of such extremely weak signals and introduce some of the basic data analysis concepts and methods used. We conclude by summarizing the current status of the sensitivities and upper limits achieved so far. These results suggest that the search for spinning neutron stars using LIGO-I is already entering a regime of “astrophysical relevance”. Developments in the near future make a detection of this type of source increasingly plausible.