New and Puzzling Types of Transient Phenomena from Accreting Supermassive Black Holes – Benny Trakhtenbrot

Our understanding of the evolving population of supermassive black holes (SMBHs) beyond the local universe is fundamentally limited to actively growing SMBHs, where relatively stable accretion of gas is thought to persist over hundreds of millions of years.
A growing number of transient phenomena in galaxy nuclei have recently begun to shed new light on SMBH demographics and the physics of gas accretion onto these objects, tracing events where this accretion has drastically intensified, diminished, and/or otherwise disturbed, over surprisingly short timescales. These phenomena include “changing look AGN” and other, poorly understood UV-bright flares from accreting SMBHs. I will review some of these new classes of transients, focusing on new results obtained with large time-domain surveys and responsive, multi-wavelength follow-up observations. While these events observationally differ from the (stellar) tidal disruption events known to date, the physics behind them may be interlinked. Together, these transient phenomena can greatly advance our understanding of SMBH accretion, teach us how and why SMBHs turn their accretion “on” and “off”, and reveal the sought-after signs of super-Eddington accretion. I will finally mention how new & upcoming surveys are going to discover & survey many more SMBH-related transients.

Horarios: November 12, 2024 15:30

Publicado por: Claudia Aguilera