Size Measurements of the Quasar X-Ray Continuum Emission Region by Analysis of Microlensing in Chandra Imagery

摘要

Microlensing offers a unique way to constrain the physical extent of different emission regions in a lensed quasar, putting to test various accretion and continuum emission models. We perform a microlensing analysis using six Chandra observations (spanning six years) of the lensed quasar SDSS 0924+0219 (redshift z_s = 1.52), in which X-ray microlensing variability is detected with high confidence. The system exhibits pronounced microlensing variability in the X-rays compared to the optical, indicating a comparatively small extent of r_(1/2) < 3.8 × 10~(14) cm (95% confidence) for the X-ray continuum emitting region, near the inner edge of the accretion disk.