A Caltech Library Service

The Two LIGO/Virgo Binary Black Hole Mergers on 2019 August 28 Were Not Strongly Lensed

Singer, Leo P. and Goldstein, Daniel A. and Bloom, Joshua S. (2019) The Two LIGO/Virgo Binary Black Hole Mergers on 2019 August 28 Were Not Strongly Lensed. . (Unpublished)

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


The LIGO/Virgo gravitational wave events S190828j and S190828l were detected only 21 minutes apart, from nearby regions of sky, and with the same source classifications (binary black hole mergers). It is therefore natural to speculate that the two signals are actually strongly lensed images of the same merger. However, an estimate of the separation of the (unknown) positions of the two events requires them to be >10° apart, much wider than the arcsecond-scale separations that usually arise in extragalactic lensing. The large separation is much more consistent with two independent, unrelated events that occurred close in time by chance. We quantify the overlap between simulated pairs of lensed events, and use frequentist hypothesis testing to reject S190828j/l as a lensed pair at 99.8% confidence.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Singer, Leo P.0000-0001-9898-5597
Goldstein, Daniel A.0000-0003-3461-8661
Bloom, Joshua S.0000-0002-7777-216X
Additional Information:We thank Ariel Goobar, Albert Kong, and Daniel Mortlock for fruitful discussions. Much of this work was performed at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1607611. This work was supported by the GROWTH (Global Relay of Observatories Watching Transients Happen) project funded by the National Science Foundation under PIRE Grant No. 1545949. DAG acknowledges support from Hubble Fellowship grant HST-HF2-51408.001-A. Support for Program number HST-HF2-51408.001-A is provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. JSB was partially supported by a Gordon and Betty Moore Foundation Data-Driven Discovery grant. We gratefully acknowledge Amazon Web Services, Inc. for a generous grant (PS IK FY2019 Q3 Caltech Gravitational Wave) that funded our use of the Amazon Web Services cloud computing infrastructure to perform the simulations. Facilities: LIGO, EGO:Virgo Software: astropy (Astropy Collaboration 2013), HEALPix (G_orski et al. 2005), Healpy (Zonca et al. 2019), ligo.skymap (
Funding AgencyGrant Number
NASA Hubble FellowshipHST-HF2-51408.001-A
Gordon and Betty Moore FoundationUNSPECIFIED
Amazon Web ServicesPS IK FY2019 Q3
Record Number:CaltechAUTHORS:20191121-083352293
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:99977
Deposited By: Tony Diaz
Deposited On:21 Nov 2019 17:33
Last Modified:02 Jun 2023 00:59

Repository Staff Only: item control page