Publications by Cameron Alexander Campbell Lemon

Tdcosmo Xvii. New Time Delays in 22 Lensed Quasars From Optical Monitoring with the Eso-vst 2.6m and Mpg 2.2m Telescopes

Frédéric Courbin, Eric Gérard Guy Paic, Vivien François Bonvin, Aymeric Alexandre Galan, Cameron Alexander Campbell Lemon

We present new time delays, the main ingredient of time delay cosmography, for 22 lensed quasars resulting from high-cadence r-band monitoring on the 2.6 m ESO VLT Survey Telescope and Max-Planck-Gesellschaft 2.2 m telescope. Each lensed quasar was typical ...

EDP SCIENCES S A2025

JWST lensed quasar dark matter survey – I. Description and first results

Cameron Alexander Campbell Lemon

All rights reserved.The flux ratios of gravitationally lensed quasars provide a powerful probe of the nature of dark matter. Importantly, these ratios are sensitive to small-scale structure, irrespective of the presence of baryons. This sensitivity may all ...

2024

Nine lensed quasars and quasar pairs discovered through spatially extended variability in Pan-STARRS

Frédéric Courbin, Aymeric Alexandre Galan, Cameron Alexander Campbell Lemon

We present the proof of concept of a method for finding strongly lensed quasars using their spatially extended photometric variability through difference imaging in cadenced imaging survey data. We applied the method to Pan-STARRS, starting with an initial ...

Edp Sciences S A2024

Searching for Strong Gravitational Lenses

Frédéric Courbin, Cameron Alexander Campbell Lemon

Strong gravitational lenses provide unique laboratories for cosmological and astrophysical investigations, but they must first be discovered - a task that can be met with significant contamination by other astrophysical objects and asterisms. Here we revie ...

Springer2024

Strong lensing by edge-on galaxies in UNIONS

Frédéric Courbin, Cameron Alexander Campbell Lemon, Elodie Marie Charlène Savary

Current searches for galaxy-scale strong lenses focus on massive Luminous Red Galaxies but tend to overlook late-type lenses, in part because of their smaller Einstein radii. We take advantage of the superb seeing of the UNIONS survey in the r-band to perf ...

2024

Gravitationally lensed quasars in Gaia - IV. 150 new lenses, quasar pairs, and projected quasars

Frédéric Courbin, Aymeric Alexandre Galan, Cameron Alexander Campbell Lemon, Adriano Agnello

We report the spectroscopic follow-up of 175 lensed quasar candidates selected using Gaia Data Release 2 observations following Paper III of this series. Systems include 86 confirmed lensed quasars and a further 17 likely lensed quasars based on imaging an ...

OXFORD UNIV PRESS2023

PS J2107-1611: A new wide-separation, quadruply imaged lensed quasar with flux ratio anomalies

Frédéric Courbin, Cameron Alexander Campbell Lemon

We report the discovery of PS J2107-1611, a fold-configuration 4.3 ''-separation quadruply lensed quasar with a bright lensed arc. It was discovered using a convolutional neural network on Pan-STARRS gri images of pre-selected quasar candidates with multip ...

Edp Sciences S A2023

STRIDES: automated uniform models for 30 quadruply imaged quasars

Frédéric Courbin, Martin Raoul Robert Millon, Cameron Alexander Campbell Lemon

Gravitational time delays provide a powerful one-step measurement of H-0, independent of all other probes. One key ingredient in time-delay cosmography are high-accuracy lens models. Those are currently expensive to obtain, both, in terms of computing and ...

OXFORD UNIV PRESS2023

Uncovering a population of gravitational lens galaxies with magnified standard candle SN Zwicky

Rémy Elie Joseph, Cameron Alexander Campbell Lemon, Johan Richard, Johannes Richard Cornelis Geerit Kruis

Detecting gravitationally lensed supernovae is among the biggest challenges in astronomy. It involves a combination of two very rare phenomena: catching the transient signal of a stellar explosion in a distant galaxy and observing it through a nearly perfe ...

NATURE PORTFOLIO2023

J1721+8842: a gravitationally lensed binary quasar with a proximate damped Lyman-alpha absorber

Frédéric Courbin, Eric Gérard Guy Paic, Hung-Hsu Chan, Martin Raoul Robert Millon, Cameron Alexander Campbell Lemon, Adriano Agnello

High-redshift binary quasars provide key insights into mergers and quasar activity, and are useful tools for probing the spatial kinematics and chemistry of galaxies along the line of sight. However, only three sub-10-kpc binaries have been confirmed above ...

EDP SCIENCES S A2022