COOL-LAMPS. Discovery of COOL J0335−1927, a Gravitationally Lensed Quasar at z = 3.27 with an Image Separation of 23.″3

Abstract

We report the discovery of COOL J0335−1927, a quasar at z = 3.27 lensed into three images with a maximum separation of 23.″3 by a galaxy cluster at z = 0.4178. To date, this is the highest redshift wide-separation lensed quasar known. In addition, COOL J0335−1927 shows several strong intervening absorbers visible in the spectra of all three quasar images with varying equivalent widths. The quasar also shows mini-broad line absorption. We construct a parametric strong gravitational lens model using ground-based imaging, constrained by the redshift and positions of the quasar images as well as the positions of three other multiply imaged background galaxies. Using our best-fit lens model, we calculate the predicted time delays between the three quasar images to be Δt AB = 499 − 146 + 141 (stat) and Δt AC = − 127 − 17 + 83 (stat) days. Folding in systematic uncertainties, the model-predicted time delays are within the ranges 240 < Δt AB < 700 and −300 < Δt AC < −30. We also present g-band photometry from archival Dark Energy Camera Legacy Survey and Pan-STARRS imaging, and new multi-epoch observations obtained between 2022 September 18 UT and 2023 February 22 UT, which demonstrate significant variability in the quasar and will eventually enable the measurement of the time delay between the three quasar images. The currently available light curves are consistent with the model-predicted time delays. This is the fifth paper from the COOL-LAMPS collaboration.

Hubble Constant Measurement from Three Large-separation Quasars Strongly Lensed by Galaxy Clusters

“…A potential misidentification of cluster-member galaxies is unlikely to be a significant source of systematic uncertainty. For example, Napier et al (2023) found that excluding a subsample of cluster members from the lens model did not significantly change the predicted time delays.…”

“…High-accuracy lens models require space-based resolution and spectroscopic follow-up. Of the seven published cluster-lensed quasars to date (Inada et al 2003(Inada et al , 2006Dahle et al 2013;Shu et al 2018Shu et al , 2019Martinez et al 2023;Napier et al 2023), only three have the necessary data available to determine H 0 : SDSS J1004+4112, SDSS J1029 +2623, and SDSS J2222+2745. In this paper, we use the available archival HST data and the latest measurements of time delays and spectroscopic redshifts of background sources from the literature to obtain an independent measurement of H 0 from these three systems.…”