### Abstract

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 10^{38} kg m^{2} 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.

Original language | English |
---|---|

Number of pages | 36 |

Journal | Astrophysical Journal |

Volume | 879 |

Issue number | 1 |

DOIs | |

Publication status | Published - 26 Jun 2019 |

### Keywords

- LIGO-Virgo
- gravitational waves
- pulsars
- gravitational-wave emission

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## Cite this

*Astrophysical Journal*,

*879*(1). https://doi.org/10.3847/1538-4357/ab20cb