A Hard Look At Relativistic Reverberation in MCG-5-23-16 & SWIFT
  J2127.4+5654: Testing the Lamp-Post Model
  X-ray reverberation mapping has emerged as a new tool to probe accretion in
AGN, providing a potentially powerful probe of accretion at the black hole
scale. The lags, along with relativistic spectral signatures are often
interpreted in light of the lamp-post model. Focusing specifically on testing
the prediction of the relativistic reverberation model, we have targeted
several of the brightest Seyfert Galaxies in X-rays with different observing
programs. Here, we report the results from two large campaigns with NuSATR
targeting MCG-5-23-16 and SWIFT J2127.4+5654 to test the model predictions in
the 3-50 keV band. These are two of three sources that showed indications of a
delayed Compton hump in early data. With triple the previously analyzed
exposures, we find no evidence for relativistic reverberation in MCG-5-23-16,
and the energy-dependent lags are consistent with a log-linear continuum. In
SWIFT J2127.4+5654, although a continuum-only model explains the data, the
relativistic reverberation model provides a significant improvement to the
energy and frequency-dependent lags, but with parameters that are not
consistent with the time-averaged spectrum. This adds to mounting evidence
showing that the lag data is not consistent with a static lamp-post model.
