X-Ray Monitoring of Gravitationally Lensed Radio-loud Quasars with Chandra

Abstract

Abstract In this work, we calculated the sizes of unresolved X-ray emission regions in three gravitationally lensed radio-loud quasars, B 1422+231, MG J0414+0534, and Q 0957+561, using a combination of imaging and spectral analysis on the X-ray data taken from the Chandra X-Ray Observatory. We tentatively detected FeKα emission lines in MG J0414+0534 and Q 0957+561 with over 95% significance, whereas, we did not significantly detect FeKα emission in B 1422+231. We constructed differential microlensing light curves from absorption corrected count rates. We subsequently performed a microlensing analysis on the X-ray microlensing light curves to measure the X-ray source sizes in rest frame soft (0.83–3.6 keV), hard (3.6–21.8 keV), and full (0.83–21.8 keV) bands, based on either Bayesian or maximum likelihood probabilities. For B 1422+231, sizes from the two methods are consistent with each other, (Bayesian), 11.81 ± 3.75 (maximum likelihood), where . However, for MG J0414+0534 and Q 0957+561, the two methods yield substantially different results suggesting that more frequently sampled data with better signal-to-noise ratio are needed to measure the source size for these two objects. Comparing the acquired size values with the radio-quiet sample in the literature we found that our results are consistent with X-ray source size scaling approximately as R X ∝ M BH with the mass of the central supermassive black hole. Our Bayesian analysis results also indicate that radio-loud quasars tend to have larger unresolved X-ray emission sizes compared to the radio-quiet ones, suggesting a more prominent jet contribution.