Abstract
The millisecond pulsars, old-recycled objects spinning with high frequency O (kHz) sustaining the deformation from their spherical shape, may emit gravitational waves (GW). These are one of the potential candidates contributing to the anisotropic stochastic gravitational-wave background (SGWB) observable in the ground-based GW detectors. Here, we present the results from a likelihood-based targeted search for the SGWB due to millisecond pulsars in the Milky Way, by analyzing the data from the first three observing runs of Advanced LIGO and Advanced Virgo detector. We assume that the shape of SGWB power spectra and the sky distribution is known a priori from the population synthesis model. The information of the ensemble source properties, i.e., the in-band number of pulsars, Nobs and the averaged ellipticity, μϵ is encoded in the maximum likelihood statistic. We do not find significant evidence for the SGWB signal from the considered source population. The best Bayesian upper limit with 95% confidence for the parameters are Nobs≤8.8×104 and μIµ≤1.4×10-6, which is comparable to the bounds on mean ellipticity with the GW observations of the individual pulsars. Finally, we show that for the plausible case of Nobs=40000, with the one year of observations, the one-sigma sensitivity on μϵ might reach 1.5×10-7 and 4.1×10-8 for the second-generation detector network having A+ sensitivity and third-generation detector network, respectively.
| Original language | English (US) |
|---|---|
| Article number | 043019 |
| Journal | Physical Review D |
| Volume | 106 |
| Issue number | 4 |
| DOIs | |
| State | Published - Aug 15 2022 |
Bibliographical note
Funding Information:The authors thank Patrick Meyers for carefully reading the manuscript and providing valuable comments. This work significantly benefitted from the interactions with the Stochastic Working Group of the LIGO-Virgo-KAGRA Scientific Collaboration. This material is based upon work supported by NSF’s LIGO Laboratory, which is a major facility fully funded by the National Science Foundation. The authors are grateful for computational resources provided by the LIGO Laboratory (CIT) supported by National Science Foundation Grants No. PHY-0757058 and No. PHY-0823459, and Inter-University Center for Astronomy and Astrophysics (Sarathi). This research has made use of data or software obtained from the Gravitational Wave Open Science Center , a service of LIGO Laboratory, the LIGO Scientific Collaboration, the Virgo Collaboration, and KAGRA. LIGO Laboratory and Advanced LIGO are funded by the United States National Science Foundation (NSF) as well as the Science and Technology Facilities Council (STFC) of the United Kingdom, the Max-Planck-Society (MPS), and the State of Niedersachsen/Germany for support of the construction of Advanced LIGO and construction and operation of the GEO600 detector. Additional support for Advanced LIGO was provided by the Australian Research Council. Virgo is funded, through the European Gravitational Observatory (EGO), by the French Centre National de Recherche Scientifique (CNRS), the Italian Istituto Nazionale di Fisica Nucleare (INFN) and the Dutch Nikhef, with contributions by institutions from Belgium, Germany, Greece, Hungary, Ireland, Japan, Monaco, Poland, Portugal, and Spain. The construction and operation of KAGRA are funded by Ministry of Education, Culture, Sports, Science and Technology (MEXT), and Japan Society for the Promotion of Science (JSPS), National Research Foundation (NRF) and Ministry of Science and ICT (MSIT) in Korea, Academia Sinica (AS) and the Ministry of Science and Technology (MoST) in Taiwan. This article has a LIGO document number LIGO-P2200056. We used numerous software packages such as n um p y , s ci p y , astropy , p y s toch , bilby , dynesty , p y m ulti n est , and matplotlib in this work. We also used the locations information for the detectors (K, I, ET-A) available in the p y cbc package .
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© 2022 American Physical Society.