Papers & Research

AGEL Survey Data Release 2: Expanding the Gravitational Lens Frontier

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Sample HST image DESJ2125-6504

The AGEL Survey team has just announced their second major data release—AGEL DR2—unveiling 138 confirmed strong gravitational lenses, up from 77 in their 2022 release. This diverse sample spans galaxy-scale to group and cluster lenses, including striking Einstein rings and rare systems like double-source plane lenses, which are especially valuable for cosmology.

These lenses were first flagged by machine learning in DES and DECaLS imaging, with an impressive 96% confirmation rate from follow-up spectroscopy. Notably, AGEL lenses are pushing the envelope with higher-redshift deflectors and sources, opening new windows into galaxy evolution and dark matter studies.

This release also includes high-resolution Hubble imaging for 71 lenses—offering stunning detail

📄 Read the full paper here.

Confirmation of Three Gravitationally Lensed Quasars

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Researchers confirmed the existence of three new gravitationally lensed quasars using data from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). These lensed quasars are interesting phenomena where the immense gravitational pull of a foreground galaxy bends and magnifies the light of the more distant quasar, creating multiple images of it. This discovery includes systems with separations ranging from 0.85 to 2.26 arcseconds, and redshifts indicating significant distances. The identification and analysis of these systems were enhanced by advanced imaging techniques and follow-up spectroscopy, which not only confirmed the lensing effect but also provided detailed characterizations of the galaxies and quasars involved. These findings add valuable examples to the catalog of known lensed quasars, which are key tools for probing dark matter, studying quasar properties, and refining our measurements of the universe’s expansion rate. This study involves combining deep, wide-field imaging with follow-up observations to confirm they are in fact gravitational lenses.

Reference paper: https://doi.org/10.1093/mnras/stab145

Is a Double Lens System Better?

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The paper “Non-coplanar gravitational lenses and the ‘communication bridge’” by Viktor T. Toth explores the concept of using multiple gravitational lenses aligned along a central axis to potentially enhance light amplification, a concept referred to as the “gravitational lens bridge.” The study employs various methodologies, including photon mapping and wave theory, to assess whether double-lens systems could outperform single-lens systems in terms of signal amplification. The results, however, indicate that these double-lens systems do not provide additional advantages over traditional single gravitational lens systems.