Gravitational waves from pulsars in the context of magnetic ellipticity

Abstract

Abstract In one of our previous articles we have considered the role of a time dependent magnetic ellipticity on the pulsars’ braking indices and on the putative gravitational waves these objects can emit. Since only nine of more than 2000 known pulsars have accurately measured braking indices, it is of interest to extend this study to all known pulsars, in particular as regards gravitational wave generation. To do so, as shown in our previous article, we need to know some pulsars’ observable quantities such as: periods and their time derivatives, and estimated distances to the Earth. Moreover, we also need to know the pulsars’ masses and radii, for which we are adopting current fiducial values. Our results show that the gravitational wave amplitude is at best $$h \sim 10^{-28}$$ h ∼ 10 - 28 . This leads to a pessimistic prospect for the detection of gravitational waves generated by these pulsars, even for Advanced LIGO and Advanced Virgo, and the planned Einstein Telescope, if the ellipticity has a magnetic origin.