Abstract
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 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.
Highlights
There have been several previous searches for persistent quasi-monochromatic gravitational waves emitted by a selection of known pulsars using data from the LIGO, Virgo, and GEO600 gravitational-wave detectors (Abbott et al.2004, 2005, 2017a, 2007, 2008, 2010; Abadie et al 2011; Aasi et al 2014)
Vela pulsars (J0534+2200 and J0835−4510, respectively), due to their large spin-down luminosities. For these two pulsars, assuming emission from the l = m = 2 mode and with the phase precisely locked to the observed rotational phase, the limits observed using the initial LIGO and Virgo detectors in Abbott et al (2008) and Abadie et al (2011), respectively, From Equations (4), (5), and (9) it can be seen that fractional uncertainties on distance will scale directly into the uncertainties on ε, Q22, and h 0sd
(2015), we have presented the first comprehensive set of results for searches that include the possibility of emission from the l = 2, m = 1 mode at the pulsar’s rotation frequency
Summary
There have been several previous searches for persistent (or continuous) quasi-monochromatic gravitational waves emitted by a selection of known pulsars using data from the LIGO, Virgo, and GEO600 gravitational-wave detectors (Abbott et al.2004, 2005, 2017a, 2007, 2008, 2010; Abadie et al 2011; Aasi et al 2014). A search including the prospect of the signal’s polarization content deviating from the purely tensorial modes predicted by general relativity has been performed in Abbott et al (2018a) None of these searches have detected a gravitational-wave signal from any of the pulsars that were targeted. The backgrounds for the sources studied here were simulated through use of the nuskybgd suite of IDL routines (Wik et al 2014) In this method, a source-free region of the FOV is selected—in our case, an annulus around each flaring YSO; each background component has a known spectral shape, and a fit of the normalizations of these components is performed based on the selected background region. The high end of the energy range for the spectral analysis was further limited by low statistics (i.e., not enough counts at higher energies to make a bin with at least 30 counts), and most spectra extend up to
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
