Prospects for detecting transient quasi-monochromatic gravitational waves from glitching pulsars with current and future detectors

ABSTRACT

Pulsars are rotating neutron stars that emit periodic electromagnetic radiation. While pulsars generally slow down as they lose energy, some also experience glitches: spontaneous increases of their rotational frequency. According to several models, these glitches can also lead to the emission of long-duration transient gravitational waves (GWs). We present detection prospects for such signals by comparing indirect energy upper limits on GW strain for known glitches with the sensitivity of current and future ground-based GW detectors. We first consider the optimistic case of generic constraints based on the glitch size and find that realistic matched-filter searches in the fourth LIGO–Virgo–KAGRA observing run (O4) could make a detection, or set constraints below these indirect upper limits, for equivalents of 36 out of 726 previously observed glitches, and 74 in the O5 run. With the third-generation Einstein Telescope or Cosmic Explorer, 35–40 per cent of glitches would be accessible. When specializing to a scenario where transient mountains produce the post-glitch GW emission, following the Yim & Jones model, the indirect upper limits are stricter. Out of the smaller set of 119 glitches with measured healing parameter, as needed for predictions under that model, only 6 glitches would have been within reach for O4 and 14 for O5, with a similar percentage as before with third-generation detectors. We also discuss how this model matches the observed glitch population.