Rapid method for preliminary identification of subthreshold strongly lensed counterparts to superthreshold gravitational-wave events

Creators: Goyal, Srashti; Kapadia, Shasvath J.; Cudell, Jean-René; Li, Alvin K. Y.; Chan, Juno C. L.

Abstract

Gravitational waves (GWs) from stellar-mass compact binary coalescences (CBCs) are expected to be strongly lensed when encountering large agglomerations of matter, such as galaxies or clusters. Searches for strongly lensed GWs have been conducted using data from the first three observing runs of the LIGO-Virgo GW detector network. Although no confirmed detections have been reported, interesting candidate lensed pairs have been identified. In this work, we delineate a preliminary analysis that rapidly identifies pairs to be further analyzed by more sophisticated Bayesian parameter estimation (PE) methods. The analysis relies on the Gaussian/Fisher approximation to the likelihood and compares the corresponding approximate posteriors on the chirp masses of the candidate pair. It additionally cross-correlates the rapidly produced localization sky areas (constructed by Bayestar sky-localization software). The analysis was used to identify pairs involving counterparts from targeted subthreshold searches to confidently detected superthreshold CBC events. The most significant candidate “super-sub” pair deemed by this analysis was subsequently found, by more sophisticated and detailed joint-PE analyses, to be among the more significant candidate pairs, but not sufficiently significant to suggest the observation of a lensed event [J. Janquart et al., Follow-up analyses to the O3 LIGO-Virgo-KAGRA lensing searches, Mon. Not. R. Astron. Soc. 526, 3 (2023)].

Copyright and License

Acknowledgement

We are thankful to P. Ajith, D. Chatterjee, H. Fong, and A. Barsode along with the astrophysical relativity group at ICTS and the LVK lensing group for helpful discussions and suggestions. We are also thankful to D. Keitel, M. Wright, and J. Janquart for their careful reading of this manuscript. Juno C. L. Chan acknowledges support from the Villum Investigator program supported by VILLUM FONDEN (Grant No. 37766) and the DNRF Chair, by the Danish Research Foundation. J. R. Cudell benefits from the support of the Fonds de la Recherche Scientifique-FNRS, Belgium, under Grant No. 4.4501.19. The authors are grateful for computational resources provided by the LIGO Laboratory and supported by National Science Foundation Grants No. PHY-0757058 and No. PHY-0823459. 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. K.A.G.R.A. is supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS) in Japan; the National Research Foundation (NRF) and Ministry of Science and ICT (MSIT) in Korea; the Academia Sinica (AS) and National Science and Technology Council (NSTC) in Taiwan. This material is based upon work supported by NSF’s LIGO Laboratory, which is a major facility fully funded by the National Science Foundation. A. K. Y. L. would like to gratefully acknowledge the support from the National Science Foundation through the Grants NSF PHY-1912594 and NSF PHY-2207758.

Files

PhysRevD.109.023028.pdf

Files (877.1 kB)

Name	Size	Download all
PhysRevD.109.023028.pdf md5:10f7fc189e3ec4312a517b3ccae8f3ba	877.1 kB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes