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NIRWL: Constraining the masses of galaxy overdensities at z > 1 in CANDELS and COSMOS through weak lensing in the near-infrared

Presentation #303.02 in the session Strong and Weak Gravitational Lensing & More — iPoster Session.

Published onJun 29, 2022
NIRWL: Constraining the masses of galaxy overdensities at z > 1 in CANDELS and COSMOS through weak lensing in the near-infrared

Measuring weak gravitational lensing (WL), a powerful probe of the distribution of dark matter, is a primary science goal for the next decade of large extragalactic surveys. Currently, however, the WL analysis has primarily been on optical-band data (e.g. HST/ACS, DES, and HSC-SSP). Near-infrared (NIR) imaging has thus far never been used for wide-field weak lensing measurements although it is now well-known that it provides superior galaxy shape measurements at z > 1. This is due to a combination of higher surface brightness, morphological k-correction, and reduced dust extinction. We present the first galaxy shear catalog with the largest set of high-resolution archival NIR images from the two widest HST/WFC3 surveys: CANDELS and COSMOS-DASH. Our NIR WL project (called NIRWL) will aim to: 1) test the fidelity of the resultant NIR WL map of dark matter in COSMOS with existing, optically-derived maps, 2) reveal galaxy over-densities at z > 1 in clusters/groups which are otherwise unknown due to photometric redshift uncertainties, 3) derive stellar/baryonic to dark matter mass ratios at z >1. Measuring these ratios on group and low-mass cluster scales will trace the relationship between the growth of large scale structure and the buildup of stellar mass. Due to the exceptional depth and spatial resolution of HST, and by leveraging the current state-of-the-art understanding of NIR detector/PSF systematics, this project serves as a critical stepping stone for cosmological measurements with upcoming Euclid and Roman surveys.

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