Description
Observations of the AGN Fairall 9 with NICER and Swift revealed a strong relationship between the flux of the UV continuum and the X-ray soft excess, indicating the presence of a “warm” Comptonized region which may act as a second reprocessor between the “hot” X-ray corona and the accretion disk. This has previously been suggested as an explanation for the weak X-ray/UV correlation observed in many AGN, and it can be confirmed using NICER's unprecedented spectral coverage of X-ray variability on timescales of days to years. Our separate NICER reverberation mapping campaign on the AGN NGC 7469 provides no evidence for a warm corona, suggesting that there is no uniform prescription for the geometry of the inner accretion flow across all AGN. I will present the X-ray spectral modeling results from both AGNs in the context of understanding their geometries and energetic properties.
