Bursts of gravitational waves due to crustquake from pulsars

Abstract

We revisit here a possibility of generation of gravitational wave (GW) bursts due to a very quick change in the quadrupole moment (QM) of a deformed spheroidal pulsar as a result of crustquake. Since it was originally proposed as a possible explanation for sudden spin-up (glitch) of pulsars, the occurrence of crustquake and its various consequences have been studied and discussed quite often in the literature. Encouraged by recent development in gravitational wave (GW) astronomy, we re-investigate the role of crustquake in the emission of GWs. Assuming exponential decay of excitation caused by crustquake, we have performed a Fourier analysis to estimate the GW strain amplitude h(t), characteristic signal amplitude $h_c(f)$ and signal-to-noise ratio (SNR) of the burst for the Crab pulsar. For exotic quark stars, multifold enhancement of these quantities are expected, which might make quark star a potential source of gravitational waves. The absence of such bursts may put several constraints on pulsars and such hypothetical stars.