Oral Presentation
Near-IR Weak-lensing (NIRWL) Measurements in the CANDELS Fields
Presenter: BoMee Lee (Korea Astronomy and Space Science Institute)
The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) fields represent the widest and deepest infrared imaging by the Hubble Space Telescope, offering an unprecedented combination of depth and area to search for shear-selected low-mass structures. In this work, we present the first infrared weak lensing (WL) analysis across all five HST CANDELS fields to identify and characterize mass overdensities. Our WL analysis detects shear-selected overdensities with masses ranging from 3.0+/-3.0 times 10^13 solar mass to 2.2 +/- 1.1 times 10^14 solar mass and a median mass of M200 = 5.0 times 10^13 solar mass. These structures span a redshift range of z = 0.2 to z = 0.9 with a mean redshift of z = 0.65. Among the 11 detected overdensities, 7 have diffuse X-ray emissions peaks in literature that are in spatial agreement with the WL peaks. Furthermore, we demonstrate that the X-ray luminosity and weak lensing scaling relation in these low-mass, high-redshift systems is consistent with relations derived from higher-mass samples. Finally, a stacked radial mass density profile of the overdensities yields a best-fit Navarro-Frenk-White (NFW) model with a concentration parameter of 5.33 and a characteristic mass of 1 times 10^14 solar mass. These results highlight the power of deep infrared space-based imaging (like JWST and Roman) for identifying and studying the mass distribution of faint, low-mass structures through weak lensing.
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