An accurate analytic mass model for lensing galaxies

TL;DR

This paper introduces an analytic mass model for lensing galaxies based on a broken power-law profile, accurately predicting galaxy properties and validated against simulations, offering a powerful tool for strong lensing studies.

Contribution

The paper presents a novel analytic mass model for lensing galaxies using a broken power-law profile, enabling efficient and accurate predictions of galaxy lensing properties.

Findings

Excellent agreement between model predictions and Illustris simulation data.

Model accurately predicts volume and surface mass density profiles.

Validated as a promising tool for strong lensing galaxy analysis.

Abstract

We develop an analytic mass model for lensing galaxies, based on a broken power-law (BPL) density profile, which is a power-law profile with a mass deficit or surplus in the central region. Under the assumption of an elliptically symmetric surface mass distribution, the deflection angle and magnification can be evaluated analytically for this new model. We compute the theoretical prediction for various quantities, including the volume and surface mass density profiles of the galaxies, and the aperture and luminosity-weighted line-of-sight velocity dispersions, and compare them to those measured from the Illustris simulation. We find an excellent agreement between our model prediction and the simulation, which validates our modeling. The high efficiency and accuracy of our model manifests itself as a promising tool for studying properties of galaxies with strong lensing.