### 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 |

### Fingerprint

### Keywords

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

### Cite this

*Astrophysical Journal*,

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

}

*Astrophysical Journal*, vol. 879, no. 1. https://doi.org/10.3847/1538-4357/ab20cb

**Searches for gravitational waves from known pulsars at two harmonics in 2015–2017 LIGO data.** / Abbott, B. P.; Angelova, S. V.; Birney, R.; Lockerbie, N. A.; Macfoy, S.; Reid, S.; LIGO Scientific Collaboration; Virgo Collaboration.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Searches for gravitational waves from known pulsars at two harmonics in 2015–2017 LIGO data

AU - Abbott, B. P.

AU - Angelova, S. V.

AU - Birney, R.

AU - Lockerbie, N. A.

AU - Macfoy, S.

AU - Reid, S.

AU - LIGO Scientific Collaboration

AU - Virgo Collaboration

N1 - This research article is hyper-authored. Please consult manuscript for full attribution details.

PY - 2019/6/26

Y1 - 2019/6/26

N2 - 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.

AB - 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.

KW - LIGO-Virgo

KW - gravitational waves

KW - pulsars

KW - gravitational-wave emission

U2 - 10.3847/1538-4357/ab20cb

DO - 10.3847/1538-4357/ab20cb

M3 - Article

VL - 879

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

ER -