# Constraining the geometry and kinematics of the quasar broad emission line region using gravitational microlensing. II. Comparing models with observations in the lensed quasar HE0435-1223

## TL;DR

This study uses gravitational microlensing simulations to analyze the broad emission line region in the lensed quasar HE0435-1223, comparing models with observations to constrain the geometry and kinematics of the BLR.

## Contribution

It introduces a method to compare simulated microlensing effects on emission lines with observations, constraining BLR models in a specific lensed quasar.

## Key findings

- Flattened geometries better reproduce observed line deformations.
- Keplerian disk model slightly favored with size constraints.
- Simulations can replicate line profile distortions.

## Abstract

The quadruply lensed quasar HE0435-1223 shows a clear microlensing effect that affects differently the blue and red wings of the H$\alpha$ line profile in its image D. To interpret these observations, and constrain the broad emission line region (BLR) properties, the effect of gravitational microlensing on quasar broad emission line profiles and their underlying continuum has been simulated considering representative BLR models and microlensing magnification maps. The amplification and distortion of the H$\alpha$ line profile, characterized by a set of four indices, can be reproduced by the simulations. Although the constraints on the BLR models set by the observed single-epoch microlensing signal are not very robust, we found that flattened geometries (Keplerian disk and equatorial wind) can more easily reproduce the observed line profile deformations than a biconical polar wind. With an additional independent constraint on the size of the continuum source, the Keplerian disk model of the H$\alpha$ BLR is slightly favored.