85 citations · 165 across the 22 of their papers we have counts for
17 papers · 1 filter
Observing population III stars in the pristine region
Sung Kei Li, Jose M. Diego, Jose M. Palencia
The detection of the long-sought Population III (Pop III) stars is, perhaps, one of the most intriguing missing links in modern astronomy. Caustic crossing events (CCE) -- extreme…
Model independent lensing sub-structure detection with multiply-imaged star clusters constellations
Leo W. H. Fung, Tom Broadhurst, Sung Kei Li +3
A broad class of dark matter (DM) models predicts the existence of sub-structures residing in DM haloes on sub-resolvable angular scales. Techniques to extract such a generic featu…
Massive stars as gravitationally lensed transients -- Insights on the high-mass initial mass function
Sung Kei Li
A robust stellar initial mass function (IMF) is crucial in any studies related to star formation. However, the direct measurement of the stellar IMF is confined to the local univer…
Lensed stars in galaxy-galaxy strong lensing -- a JWST prediction for the Cosmic Horseshoe
Sung Kei Li, Luke Weisenbach, Thomas E. Collett +10
We explore for the first time the possibility of detecting lensed star transients in galaxy-galaxy strong lensing systems upon repeated, deep imaging using the {\it James-Webb Spac…
Magnification bias reveals severe contamination in Hubble Frontier Field photo-z catalogs
Jiashuo Zhang, Jeremy Lim, Tom Broadhurst +4
Gravitational lensing by massive galaxy clusters enables faint distant galaxies to be more abundantly detected than in blank fields, thereby allowing one to construct galaxy lumino…
Signatures of Fuzzy Dark Matter Inside Radial Critical Curves
J. M. Palencia, Paloma Morilla, Sung Kei Li +5
We investigate the strong gravitational lensing properties of fuzzy dark matter (FDM) halos, focusing on the magnification properties near radial critical curves (CCs). Using simul…
Transient star B/R ratio and star formation in lensed galaxies
Sung Kei Li, Jose M. Palencia, Jose M. Diego +8
The extreme magnification from galaxy clusters and microlenses therein allows the detection of individual, luminous stars in lensed galaxies as transient events, and hence provides…
Constraining the z 1 Initial Mass Function with {\it HST} and {\it JWST} Lensed Stars in MACS J0416.1-2403
Sung Kei Li, Jose M. Diego, Ashish K. Meena +19
Our understanding of galaxy properties and evolution is contingent on knowing the initial mass function (IMF), and yet to date, the IMF is constrained only to local galaxies. Indiv…
Multi-copy Axion Transfer Function and Observational Implications of Effective de Broglie Scales
Jiashuo Zhang, Tom Broadhurst, Jeremy Lim +2
Ultra-light axions are viable fuzzy/wave-like dark matter (DM) candidates generically predicted by the String Axiverse paradigm with multiple particle copies, whereas most of th…
A high-resolution view of the source-plane magnification near cluster caustics in wave dark matter models
Jose M. Diego, Alfred Amruth, Jose M. Palencia +10
We present the highest resolution images to date of caustics formed by wave dark matter (DM) fluctuations near the critical curves of cluster gravitational lenses. We describe t…
Dark Matter distinguished by skewed microlensing in the "Dragon Arc"
Tom Broadhurst, Sung Kei Li, Amruth Alfred +18
Microlensed stars recently discovered by JWST & HST follow closely the winding critical curve of A370 along all sections of the ``Dragon Arc" traversed by the critical curve. These…
Imaging dark matter at the smallest scales with lensed stars
J. M. Diego, Sung Kei Li, Alfred Amruth +19
Observations of caustic-crossing galaxies at redshift show a wealth of transient events. Most of them are believed to be microlensing events of highly magnified stars. Ea…
Flashlights: Transients among Gravitationally-Lensed Star Clusters in the Dragon Arc. I. Stellar Microlensing vs Stellar Outbursts
Sung Kei Li, Jose M. Diego, Patrick L. Kelly +8
We report the discovery of transients among star clusters in a distant galaxy that is gravitationally lensed by a foreground galaxy cluster, and explore whether these transients co…
Einstein rings modulated by wavelike dark matter from anomalies in gravitationally lensed images
Alfred Amruth, Tom Broadhurst, Jeremy Lim +10
Unveiling the true nature of Dark Matter (DM), which manifests itself only through gravity, is one of the principal quests in physics. Leading candidates for DM are weakly interact…
Flashlights: Properties of Highly Magnified Images Near Cluster Critical Curves in the Presence of Dark Matter Subhalos
Liliya L. R. Williams, Patrick L. Kelly, Tommaso Treu +7
Dark matter subhalos with extended profiles and density cores, and globular stars clusters of mass , that live near the critical curves in galaxy cluster lenses…
Flashlights: More than A Dozen High-Significance Microlensing Events of Extremely Magnified Stars in Galaxies at Redshifts z=0.7-1.5
Patrick L. Kelly, Wenlei Chen, Amruth Alfred +23
Once only accessible in nearby galaxies, we can now study individual stars across much of the observable universe aided by galaxy-cluster gravitational lenses. When a star, compact…
Flashlights: An Off-Caustic Lensed Star at Redshift = 1.26 in Abell 370
Ashish Kumar Meena, Wenlei Chen, Adi Zitrin +10
We report the discovery of a transient seen in a strongly lensed arc at redshift in \emph{Hubble Space Telescope} imaging of the Abell 370 galaxy cluster. The tr…