Presentation #129.03 in the session AGN and Quasars II.
AGN X-ray spectra often show a reflection component. A necessary consequence of X-ray reflection is that the reflecting material also absorbs and eventually re-radiates some fraction of the total X-ray energy. Many studies assume that this “X-ray reprocessing” paradigm accounts for the origin of UV/optical variability in AGN. However, there is scarce observational evidence in favor of X-ray reprocessing. On the contrary, recent multiwavelength monitoring campaigns find poor correlation between X-ray and UV/optical light curves, posing a strong challenge to standard X-ray reprocessing models. I will discuss an observational test of the X-ray reprocessing paradigm based on separating the primary and reflected X-ray components of high signal-to-noise X-ray spectra. The reflected X-rays should correlate with the UV/optical reprocessing variations — previous studies did not separate the primary and reflected X-ray components in the monitoring light curves and so may have missed any correlation. Lastly, I will show how the Transiting Exoplanet Survey Satellite (TESS) can be used to anchor AGN multiwavelength monitoring campaigns. With TESS’s large field of view, it is relatively easy to coordinate simultaneous monitoring campaigns with X-ray observatories. I will present preliminary results from such a monitoring campaign of NGC 4151 and NGC 4051, using light curves from TESS and NICER obtained in March of 2022.