activity
20242026
collaborators

14 papers

astro-ph.GA2026

First Statistical Study of Over 100 Magnified Stellar Events at Redshift with JWST

J. M. Palencia, Fengwu Sun, J. M. Diego +25

Highly magnified stars at cosmological distances () become detectable thanks to microlensing by intracluster stars near the critical curves of galaxy clusters. Multi…

astro-ph.GA2026

Extragalactic microlensing through Ultra Diffuse Galaxies

Sung Kei Li, Thomas Broadhurst, Jose M. Diego +3

Stellar microlensing is a powerful method to constrain compact dark matter models, uncover binary stars, and exoplanets during caustic crossing events. At cosmological distances, {…

astro-ph.CO2026

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…

astro-ph.CO2026

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…

astro-ph.CO2025

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 t…

astro-ph.GA2025

JWST's PEARLS: Temperatures of Nine Highly Magnified Stars in a Galaxy at Redshift 0.94 and Simulated Stellar Population Dependence on Stellar Metallicity and the Initial Mass Function

Hayley Williams, Patrick L. Kelly, Rogier A. Windhorst +17

We present stellar atmosphere modeling of JWST NIRCam photometry of nine highly magnified individual stars in a single galaxy at redshift z=0.94 known as the Warhol arc, which is s…