CDM and SIDM Interpretations of the Strong Gravitational Lensing Object JWST-ER1
Abstract
van Dokkum et al. (arXiv:2309.07969) reported the discovery of JWST-ER1, a strong lensing object at redshift z≈2, using data from the James Webb Space Telescope. The lens mass within the Einstein ring is 5.9 times higher than the expected stellar mass from a Chabrier initial mass function, indicating a high dark matter density. In this work, we show that a cold dark matter halo, influenced by gas-driven adiabatic contraction, can account for the observed lens mass. We interpret the measurement of JWST-ER1 in the self-interacting dark matter scenario and show that the cross section per particle mass σ/m≈0.1~ cm2/g is generally favored. Intriguingly, σ/m≈0.1~ cm2/g can also be consistent with the strong lensing observations of early-type galaxies at redshift z≈0.2, where adiabatic contraction is not observed overall.