We present a search for gravitational waves from 222 pulsars with rotation frequencies ≳10 Hz. We use advanced LIGO data from its first and second observing runs spanning 2015–2017, which provides the highest-sensitivity gravitational-wave data so far obtained. In this search we target emission from both the l = m = 2 mass quadrupole mode, with a frequency at twice that of the pulsar's rotation, and the l = 2, m = 1 mode, with a frequency at the pulsar rotation frequency. The search finds no evidence for gravitational-wave emission from any pulsar at either frequency. For the l = m = 2 mode search, we provide updated upper limits on the gravitational-wave amplitude, mass quadrupole moment, and fiducial ellipticity for 167 pulsars, and the first such limits for a further 55. For 20 young pulsars these results give limits that are below those inferred from the pulsars' spin-down. For the Crab and Vela pulsars our results constrain gravitational-wave emission to account for less than 0.017% and 0.18% of the spin-down luminosity, respectively. For the recycled millisecond pulsar J0711−6830 our limits are only a factor of 1.3 above the spin-down limit, assuming the canonical value of 10³⁸ kg m² for the star's moment of inertia, and imply a gravitational-wave-derived upper limit on the star's ellipticity of 1.2 × 10^-8. We also place new limits on the emission amplitude at the rotation frequency of the pulsars.

Item Type:	Refereed Article
Keywords:	gravitational waves, pulsars, neutron stars
Research Division:	Physical Sciences
Research Group:	Astronomical sciences
Research Field:	Galactic astronomy
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the physical sciences
UTAS Author:	Palfreyman, J (Dr Jim Palfreyman)
UTAS Author:	Siellez, K (Dr Karelle Siellez)
ID Code:	147439
Year Published:	2019
Web of Science® Times Cited:	56
Deposited By:	Physics
Deposited On:	2021-11-01
Last Modified:	2022-08-17
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