1.2k citations · 5k across the 52 of their papers we have counts for
52 papers
Constraining compact dark matter with time-varying quasar equivalent widths
Georgios Vernardos, James Hung Hsu Chan, Frederic Courbin
One of the possible explanations for dark matter is that of compact dark objects of baryonic origin, such as black holes or even planets. Accumulating evidence, including the disco…
Accelerating lensed quasar discovery and modeling with physics-informed variational autoencoders
Irham T. Andika, Stefan Schuldt, Sherry H. Suyu +5
Strongly lensed quasars provide valuable insights into the rate of cosmic expansion, the distribution of dark matter in foreground deflectors, and the characteristics of quasar hos…
Boson Star Normal Modes
James Hung-Hsu Chan, Sergey Sibiryakov, Wei Xue
Boson stars are gravitationally bound objects that arise in ultralight dark matter models and form in the centers of galactic halos or axion miniclusters. We systematically study t…
Survey of Gravitationally Lensed Objects in HSC Imaging (SuGOHI). IX. Discovery of Strongly Lensed Quasar Candidates
James H. H. Chan, Kenneth C. Wong, Xuheng Ding +7
We report the discovery of new lensed quasar candidates in the imaging data of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) DR4, covering of the sk…
Latent Stochastic Differential Equations for Modeling Quasar Variability and Inferring Black Hole Properties
Joshua Fagin, Ji Won Park, Henry Best +6
Quasars are bright and unobscured active galactic nuclei (AGN) thought to be powered by the accretion of matter around supermassive black holes at the centers of galaxies. The temp…
The impact of human expert visual inspection on the discovery of strong gravitational lenses
Karina Rojas, Thomas E. Collett, Daniel Ballard +53
We investigate the ability of human 'expert' classifiers to identify strong gravitational lens candidates in Dark Energy Survey like imaging. We recruited a total of 55 people that…
A Highly Magnified Gravitationally Lensed Red QSO at z = 2.5 with a Significant Flux Ratio Anomaly
Eilat Glikman, Cristian E. Rusu, Geoff C. -F. Chen +12
We present the discovery of a gravitationally lensed dust-reddened QSO at z = 2.517, identified in a survey for QSOs by infrared selection. Hubble Space Telescope imaging reveals a…
Condensation and Evaporation of Boson Stars
James Hung-Hsu Chan, Sergey Sibiryakov, Wei Xue
Axion-like particles, including the QCD axion, are well-motivated dark matter candidates. Numerical simulations have revealed coherent soliton configurations, also known as boson s…
Survey of Gravitationally-lensed Objects in HSC Imaging (SuGOHI). VIII. New galaxy-scale lenses from the HSC SSP
Kenneth C. Wong, James H. H. Chan, Dani C. -Y. Chao +5
We conduct a search for galaxy-scale strong gravitational lens systems in Data Release 4 of the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP), consisting of data taken up to…
Discovery of Strongly Lensed Quasars in the Ultraviolet Near Infrared Optical Northern Survey (UNIONS)
J. H. H. Chan, C. Lemon, F. Courbin +13
We report the discovery of five new doubly-imaged lensed quasars from the first 2500 square degrees of the ongoing Canada-France Imaging Survey (CFIS), which is a component of the…
Constraining quasar structure using high-frequency microlensing variations and continuum reverberation
E. Paic, G. Vernardos, D. Sluse +4
Gravitational microlensing is a powerful tool to probe the inner structure of strongly lensed quasars and to constrain parameters of the stellar mass function of lens galaxies. Thi…
Strong lensing in UNIONS: Toward a pipeline from discovery to modeling
E. Savary, K. Rojas, M. Maus +16
We present a search for galaxy-scale strong gravitational lenses in the initial 2 500 square degrees of the Canada-France Imaging Survey (CFIS). We designed a convolutional neural…
J17218842: a gravitationally lensed binary quasar with a proximate damped Lyman- absorber
C. Lemon, M. Millon, D. Sluse +5
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…
Strong lens systems search in the Dark Energy Survey using Convolutional Neural Networks
K. Rojas, E. Savary, B. Clément +8
We performed a search for strong lens galaxy-scale systems in the first data release of the Dark Energy Survey (DES), from a color-selected parent sample of 18~745~029 Luminous Red…
HOLISMOKES -- VII. Time-delay measurement of strongly lensed Type Ia supernovae using machine learning
S. Huber, S. H. Suyu, D. Ghoshdastidar +7
The Hubble constant () is one of the fundamental parameters in cosmology, but there is a heated debate around the 4 tension between the local Cepheid distance ladder and…
HOLISMOKES -- V. Microlensing of type II supernovae and time-delay inference through spectroscopic phase retrieval
J. Bayer, S. Huber, C. Vogl +5
We investigate strongly gravitationally lensed type II supernovae (LSNe II) for time-delay cosmography incorporating microlensing effects, which expands on previous microlensing st…
Strongly lensed candidates from the HSC transient survey
Dani C. -Y. Chao, James H. -H. Chan, Sherry H. Suyu +5
We present a lensed quasar search based on the variability of lens systems in the HSC transient survey. Starting from 101,353 variable objects with i-band photometry in the HSC tra…
HOLISMOKES -- III. Achromatic Phase of Strongly Lensed Type Ia Supernovae
S. Huber, S. H. Suyu, U. M. Noebauer +5
To use strongly lensed Type Ia supernovae (LSNe Ia) for cosmology, a time-delay measurement between the multiple supernova (SN) images is necessary. The sharp rise and decline of S…
Survey of Gravitationally lensed Objects in HSC Imaging (SuGOHI) -- VII. Discovery and Confirmation of Three Strongly Lensed Quasars
Anton T. Jaelani, Cristian E. Rusu, Issha Kayo +13
We present spectroscopic confirmation of three new two-image gravitationally lensed quasars, compiled from existing strong lens and X-ray catalogs. Images of HSC J091843.2702200…
Survey of Gravitationally-lensed Objects in HSC Imaging (SuGOHI). VI. Crowdsourced lens finding with Space Warps
Alessandro Sonnenfeld, Aprajita Verma, Anupreeta More +19
Strong lenses are extremely useful probes of the distribution of matter on galaxy and cluster scales at cosmological distances, but are rare and difficult to find. The number of cu…
Multiple Images and Flux Ratio Anomaly of Fuzzy Gravitational Lenses
James H. H. Chan, Hsi-Yu Schive, Shing-Kwong Wong +2
Extremely light bosonic wave dark matter (DM) is an emerging dark matter candidate contesting the conventional cold dark matter paradigm and a model subject to intense scrutiny…
HOLISMOKES -- I. Highly Optimised Lensing Investigations of Supernovae, Microlensing Objects, and Kinematics of Ellipticals and Spirals
S. H. Suyu, S. Huber, R. Cañameras +10
We present the HOLISMOKES programme on strong gravitational lensing of supernovae as a probe of supernova (SN) physics and cosmology. We investigate the effects of microlensing on…
Survey of Gravitationally-lensed Objects in HSC Imaging (SuGOHI). V. Group-to-cluster scale lens search from the HSC-SSP Survey
Anton T. Jaelani, Anupreeta More, Masamune Oguri +11
We report the largest sample of candidate strong gravitational lenses belonging to the Survey of Gravitationally-lensed Objects in HSC Imaging for group-to-cluster scale (SuGOHI-c)…
TDCOSMO. I. An exploration of systematic uncertainties in the inference of from time-delay cosmography
M. Millon, A. Galan, F. Courbin +22
Time-delay cosmography of lensed quasars has achieved 2.4% precision on the measurement of the Hubble constant, . As part of an ongoing effort to uncover and control systemati…