How does the Eddington limit affect the multiwavelength variability of AGN?
Abstract
AGN emit a significant fraction of their power as a variable X-ray continuum, which is usually observed to correlate with variability in UV/optical emission.However, such correlations are not always observed. For example, the recent 40 day long XMM-Newton large programme on IRAS 13224-3809 showed no correlation between X-ray and W1-band variability.This source is believed to be accreting at around the Eddington limit and other discoveries in the new dataset, such as a variable Ultra-Fast Outlow, demonstrate that more than the thin accretion disc and corona structure of sub-Eddington AGN is present in this source.Other highly accreting AGN also lack correlations between the observed X-ray and optical emission, suggesting that changes to the accretion flow at around the Eddington limit may be responsible for the lack of correlation.We will present results from the IRAS 13224-3809 campaign and compare these with findings from other AGN monitoring campaigns to show what such campaigns can teach us about differences in the accretion structure between moderately and highly accreting systems.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E.463B