Limits on gravitational wave emission from selected pulsars using LIGO data

TL;DR

This paper reports the first direct upper limits on gravitational wave emissions from 26 pulsars, using LIGO data and radio observations to improve sensitivity and constrain pulsar ellipticities.

Contribution

It introduces a multi-detector coherent analysis with radio-guided phase templates to set new upper limits on gravitational waves from pulsars.

Findings

Upper limits as low as a few times 10^{-24} on strain amplitude.

Ellipticity constraints below 10^{-5} for nearby pulsars.

First direct limits for 26 of the 28 pulsars studied.

Abstract

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multi-detector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational wave signals. The unprecedented sensitivity of the detectors allow us to set strain upper limits as low as a few times $10^{-24}$. These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than $10^{-5}$ for the four closest pulsars.