Turning AGN Microlensing From a Curiosity Into a Tool

TL;DR

This paper discusses recent advances in using microlensing of quasars as a powerful tool for probing dark matter, stellar masses, and quasar structures, enabled by new data and Bayesian analysis methods.

Contribution

It introduces Bayesian analysis techniques that transform microlensing from a curiosity into a practical tool for astrophysical research.

Findings

Preliminary results for dark matter probing

Measurements of stellar mass in lens galaxies

Insights into quasar accretion disk structures

Abstract

Microlensing of gravitationally lensed quasars by the stars in the foreground lens galaxy can be used to probe the nature of dark matter, to determine the mean stellar mass in the lens galaxy, and to measure the internal structure of quasar accretion disks. Until recently, little progress has been made toward using microlensing for these purposes because of the difficulty in obtaining the necessary data and the lack of good analysis methods. In the last few years, both problems have been solved. In particular, Bayesian analysis methods provide a general approach to measuring quantities of physical interest and their uncertainties from microlensing light curves. We discuss the data and the analysis methods and show preliminary results for all three astrophysical applications.