"The process of accretion onto black holes is well studied at sub-Eddington rates, but as the flow approaches the Eddington limit for spherical accretion, our understanding breaks down. This project seeks to investigate the properties of accretion in the Eddington-regime using the latest advanced spectral-timing methods. These will provide a hitherto unseen view of accretion at extreme rates, the nature of which will have important consequences for our view of quasar growth in the early universe and the behaviour of outflows seen to originate from these bright accreting sources. The project will incorporate the vast quantities of excellent data available for Eddington rate X-ray binaries (XRBs) and also include the available high-quality data for Eddington rate active galactic nuclei (AGN) and ultra-luminous X-ray sources (ULXs). Such a wide survey of properties of Eddington-regime objects has never been undertaken, yet the broad range of masses incorporated into the sample will reveal behaviours spanning many decades in scaled frequency and energy making for a complete characterisation of the regime. The broad survey will identify any patterns of variability originating from the global properties of Eddington accretion and may also identify the presence of instabilities with important consequences for our models describing the accretion flow. In searching for the signatures of uncollimated outflows, we will identify the physical properties of the wind and also the effect these have upon the observed variability properties. Due to the focus on timing behaviour and the significant quantity of XRB physics that will be required, the API at the University of Amsterdam is the natural host institution for this project as it benefits from having unparalleled group expertise which can provide the necessary, high level of training and development."
Field of science
- /natural sciences/physical sciences/astronomy/astrophysics/black hole
Call for proposal
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