Letters of Intent received in 2024

LoI 2026-2216
Magnetic Fields in Active Galactic Nuclei Down to the Event Horizon Scale

Topics

Black holes
Active galactic nuclei
Magnetic fields near compact relativistic objects
Energy extraction and transport in AGN
Formation and propagation of relativistic jets
Physics of accretion disks
Extreme states of matter
General relativity
Radio interferometry
Optical/IR interferometry
Measurements of magnetic fields on the most compact scales in AGN

Rationale

The objective of this proposed symposium is to address the complex interactions of physical phenomena in the vicinity of cosmic black holes, with a specific focus on the crucial role of magnetic fields. Despite extensive research at larger scales, a comprehensive understanding of magnetic field behaviour at smaller scales remains a major objective. The objective of this symposium is to facilitate collaboration among scientists specialised in observations, magnetic field reconstruction and modelling, with the aim of elucidating the complexities of magnetic field dynamics around black holes.

Notable advances, as exemplified by the achievements of the Event Horizon Telescope Collaboration (EHT) and the Global mm-VLBI Array (GMVA), have considerably enhanced our comprehension of supermassive black holes. Nevertheless, in order to fully ascertain the existence and characteristics of these black holes, precise data concerning the magnetic field in the vicinity of the event horizon is indispensable. The symposium will address both ongoing and future observational programmes, with a particular focus on multi-frequency polarimetric radio interferometric imaging and opacity measurements. In conjunction with cutting-edge image analysis and relativistic flow modelling techniques, these endeavours are anticipated to enhance our comprehension of magnetic field dynamics in the vicinity of black holes.

The overarching objective of this symposium is to establish the most rigorous constraints on the strength and structure of the magnetic field in the vicinity of the event horizon. This will provide critical, independent evidence, complementary to mm-VLBI imaging, for the existence of black holes and their event horizons. Furthermore, the symposium will present studies complemented by observations and numerical modelling of plasma emission downstream in the jet, initially at parsec scales and eventually at kiloparsec scales, using other interferometers. This comprehensive approach promises to shed new light on our understanding of black holes and the physics that govern them.

(Note, the date is to be confirmed, it will be a week in June/July/August, not the week of the Solar eclipse which crosses over Spain)