James Webb Space Telescope Feed Post

Date: 4/3/2024

Arxiv: CDM and SIDM Interpretations of the Strong Gravitational Lensing Object JWST-ER1 Published: 2/24/2024 5:43:45 PM Updated: 4/1/2024 11:33:41 PM

Paper abstract: van Dokkum et al. (arXiv:2309.07969) reported the discovery of JWST-ER1, astrong lensing object at redshift z~2, using data from the James WebbSpace Telescope. The lens mass within the Einstein ring is 5.9 times higherthan the expected stellar mass from a Chabrier initial mass function,indicating a high dark matter density. In this work, we show that a cold darkmatter halo, influenced by gas-driven adiabatic contraction, can account forthe observed lens mass. We interpret the measurement of JWST-ER1 in theself-interacting dark matter scenario and show that the cross section perparticle mass \sigma/m~0.1~{\rm cm^2/g} is generally favored.Intriguingly, \sigma/m~0.1~{\rm cm^2/g} can also be consistent with thestrong lensing observations of early-type galaxies at redshift z~0.2,where adiabatic contraction is not observed overall.