Exploring Photoionised Outflowing Winds in Active Galactic Nuclei

Grafton-Waters, Samuel;


Exploring Photoionised Outflowing Winds in Active Galactic Nuclei.

Doctoral thesis (Ph.D), UCL (University College London).


In this Thesis I present a study of the ionised outflowing winds within four active galactic nuclei (AGN): NGC 7469 (Seyfert type 1), NGC 1068 and NGC 5643 (both type 2), and NGC 3227 (type 1 during obscuration). The aim of this work, based on high-resolution X-ray spectroscopy using the XMM-Newton Reflection Grating Spectrometer (RGS), is to understand the ionisation state and kinematics of the outflowing winds and determine their locations with respect to the central supermassive black hole (SMBH).

The emission line region within NGC 7469 is found to be made up of two narrow components and a possible broad component. The distances of these ionised plasma phases from the SMBH depend strongly on the volume filling factor, which is currently unknown. The 0.3 – 10 keV spectrum of NGC 1068 is analysed by simultaneously modelling the XMM-Newton RGS and EPIC-PN data, comparing observations taken in 2000 and 2014. I find that four photoionised components are required to explain the emission features in both epochs. I also find strong evidence for collisionally ionised emission. NGC 5643 is the target of an XMM-Newton AO20 proposal which I submitted and was accepted, with the aim of studying the possible X-ray outflow-induced star formation as seen in the optical band. Analysis of archival observations and preliminary modelling by simulating data with larger exposure times than previously available are presented here. Finally, NGC 3227 was observed to undergo an obscuration event at the end of 2019. I study the EPIC-PN spectrum in order to investigate what drives the observed variability.

My analysis of the outflowing winds in AGN show that the kinematics and ionisation states are similar in different types of objects, suggesting that similar plasma clouds inhabit type 1 and type 2 AGN, thus giving support to the standard model of AGN.

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