BHmapping · Mapping the inner flow around accreting black holes
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-02-01 → 2021-01-31
- EU contribution
- €134,462
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Mapping the inner flow around accreting black holes
Astrophysical black holes (BH) are extremely simple objects: they are fully described by their mass and spin. However, the way they are fed and how they influence their surroundings is an outstanding and complex problem of high energy astrophysics. Accretion is the physical process that makes BH “visible” to our detectors, thus allowing us to see close to the BH and offering the opportunity to measure its parameters. On the other hand, the strong magnetic and radiation fields close to the BH can result in the production of jets and winds of expelled plasma which influence the host galaxy. In addition, the observed phenomenology changes significantly throughout the life cycle of a BH system. Understanding how accretion and ejection of plasma around BHs operate is of the utmost importance in order to understand how BHs work. The inner regions of BH-accreting systems (from BH X-ray binaries - BHXRB - to active galactic nuclei - AGN) are key to study these mechanisms. Nonetheless, the distribution of the accreted gas orbiting close to the BH, its dependence on the accretion state, and the way this leads to the formation of outflows is not well understood. The BHmapping project addressed these open questions by studying the geometry of the gas around BHs of different mass and in different accretion states. The project relied on the use of advanced spectral-timing analysis techniques, which were applied to new X-ray data from the highest throughput and highest time resolution detectors, as well as state-of-the-art and newly developed X-ray spectral-timing models to interpret the results.
Data: CORDIS, © European Union
Project objective
Understanding the behaviour of matter in the close environments of astrophysical black holes (BH) is one of the biggest challenges of modern astrophysics. This project aims to address the fundamental problem of determining the geometry of the inflowing matter around accreting BHs. The geometrical distribution of the accreted gas is a hotly disputed and still unsolved issue. Its relevance is tightly linked to the possibility of testing the effects of General Relativity in the vicinity of BHs. Moreover, it is strictly related to other fundamental problems, in particular regarding the nature and location of the X-ray source, the mechanism responsible for the launch of the jet and the determination of the BH spin. We propose to use a novel approach known as “X-ray reverberation”. This is based on the use of innovative cross-spectral-timing techniques to study the temporal response of the accreting gas to flux variations of the central X-ray source, thus allowing distances among the different emitting regions to be constrained. This project will use the best quality data, including those provided by the ASTROSAT satellite and the NICER payload. We aim to: map the evolving geometry of the accretion flow as a function of accretion state in Galactic BH X-ray binaries; study the coupling between the accretion flow and the jet; develop theoretical spectral-timing models to explain the data; investigate how these behaviours extend to the supermassive BHs in active galactic nuclei. The candidate is an experienced researcher (ER) in the field of observational X-ray astronomy, and has pioneered the application of the X-ray reverberation method to several accreting BH systems. By exploiting the long-term and renowned expertise in theoretical modelling of accretion processes around BHs of the High Energy Astrophysics group at the Nicolaus Copernicus Astronomical Center of the Polish Academy of Science, this research will allow the ER to emerge with new and competitive skills.
Original text from CORDIS.
Participants
- CENTRUM ASTRONOMICZNE IM. MIKOLAJA KOPERNIKA POLSKIEJ AKADEMII NAUK · WarszawaCoordinatorPoland
Links
Data: CORDIS, © European Union