Acceleration and cooling of the corona during X-ray flares from the Seyfert galaxy I Zw 1

Understand

We report on X-ray flares that were observed from the active galactic nucleus I Zwicky 1 (I Zw 1) in 2020 January by the NuSTAR and XMM-Newton observatories.

• The X-ray spectrum is well-described by a model comprised of the continuum emission from the corona and its reflection from the accretion disc around a rapidly spinning (a > 0.94) black hole.
• In order to model the broadband spectrum, it is necessary to account for the variation in ionisation across the disc.
• Analysis of the X-ray spectrum in time periods before, during and after the flares reveal the underlying changes to the corona associated with the flaring.