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arXiv · 2504.20223

Testing X-ray Reprocessing and Mapping the Soft Excess of NGC 7469 with NICER

Ethan R. Partington·Edward M. Cackett·Rick Edelson·Keith Horne·Jake A. Miller·Aaron J. Barth·Jonathan Gelbord·Juan V. Hernández Santisteban
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Abstract

We present an X-ray/UV reverberation analysis of NGC 7469 across 210 days, using daily NICER observations with contemporaneous monitoring by Swift UVOT+XRT. We model the X-ray spectrum with a power law continuum and a soft excess during each NICER epoch. These emission sources demonstrate correlated flux variability with a lag consistent with zero days. We find that the power law emission is consistent with a compact X-ray corona, and that the soft excess can be explainedby reflected coronal emission from the inner accretion disk. We test the relationship between changes in the flux of the X-ray corona and the UVW2 continuum, finding strong correlation and a negative X-ray lag of less than one day. This is consistent with a scenario in which the X-ray corona drives the UVW2 light curve through thermal reprocessing

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Ethan R. Partington, Edward M. Cackett, Rick Edelson, Keith Horne, Jake A. Miller, Aaron J. Barth, Jonathan Gelbord, Juan V. Hernández Santisteban. 2025-04-28. Testing X-ray Reprocessing and Mapping the Soft Excess of NGC 7469 with NICER. https://doi.org/10.3847/1538-4357%2Fadd3ef

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