# On the detectability of strong lensing in near-infrared surveys

**Authors:** Philip Holloway, Aprajita Verma, Philip J. Marshall, Anupreeta More, Matthias Tecza  
**arXiv:** [2308.00851](https://arxiv.org/abs/2308.00851)  
**Date:** 2023-08-01  
**Summary page:** https://www.summarizepaper.com/en/paper/2308.00851v1/

## Key points

- Philip Holloway and colleagues investigate detectability of strong gravitational lensing in near-infrared surveys
- Focus on existing and forthcoming deep surveys, including JWST and VISTA
- Utilize JAGUAR galaxy catalogue for estimating lensing frequency
- Extrapolate findings to surveys by Euclid and Nancy Grace Roman Space Telescope
- Methodology does not assume nature of lens, probes wide range of lens masses
- Generate realistic simulated lensed sources from same catalogue for verification
- JWST has potential to discover approximately 65 lensed systems in COSMOS-Web, with 25% having source redshifts exceeding 4
- Deeper and narrower programs like JADES-Medium may find fewer systems (~25), but probe more typical source galaxies in terms of flux and mass
- 55-80% of surveyed regions have detectable multiple imaging, suggesting new diverse strong lens systems will likely be uncovered in near-infrared surveys compared to visible surveys

## Summary

In their study, Philip Holloway and colleagues investigate the detectability of strong gravitational lensing in near-infrared surveys. They focus on existing and forthcoming deep surveys, including those conducted by the James Webb Space Telescope (JWST) and the Visible and Infrared Survey Telescope for Astronomy (VISTA). To estimate the lensing frequency, they utilize the JAdes extraGalactic Ultradeep Artificial Realisations (JAGUAR) galaxy catalogue which incorporates comprehensive photometry and morphologies for each galaxy. While the JAGUAR simulations are limited in area and less suitable for wide-area surveys, the researchers extrapolate their findings to surveys carried out by Euclid and the Nancy Grace Roman Space Telescope. Importantly, their methodology does not make assumptions about the nature of the lens itself, allowing them to probe a wide range of lens masses. To verify their expectations, Holloway et al. generate realistic simulated lensed sources from the same catalogue and select those that have a signal-to-noise ratio greater than 20 that are detectable. They then compare these results with published lens samples selected in visible bands and find broad consistency. The authors report that JWST has potential to discover approximately 65 lensed systems in COSMOS-Web with around 25% of them having source redshifts exceeding 4. However deeper and narrower programs like JADES-Medium may find fewer systems (~25), albeit probing more typical source galaxies in terms of flux and mass. Furthermore their investigation reveals that 55-80% of surveyed regions have detectable multiple imaging suggesting that forthcoming near infrared surveys will likely uncover new diverse strong lens systems specifically higher redshift sources (e.g., JWST) as well as dustier more massive older sources (e.g., Euclid NISP) compared to those typically detected in corresponding visible surveys. Overall this study provides valuable insights into potential of near infrared surveys for discovering and characterizing strong gravitational lensing events which could lead to uncovering new types of lenses such as higher redshift sources or dustier more massive older sources compared to those typically found in visible band surveys.