Special Session SS32
24 June 2025
Probing the dynamics of galactic nuclei with nuclear transients.
Aims and scope
Multi-messenger transients in the nuclei of galaxies are unique probes of supermassive black hole (SMBH) physics, but many remain poorly understood. Achieving a deeper understanding of the diversity amongst such transients, and their different physical processes, is an essential step as we enter a new era of astronomical instrumentation. Tidal disruption events (TDEs) have been associated with potential neutrino detections, and are predicted to generate gravitational waves that may be detectable with LISA. Although TDEs are still the best-studied class among nuclear transients, the field is advancing rapidly with the discovery of partial/repeated TDEs as well as multi-wavelength (X-ray, radio, infrared) flares months-years after disruption.
Recent breakthroughs in wide-field surveys, operating across the electromagnetic spectrum, have led to an increased discovery rate of fascinating nuclear transients, with peculiar new subclasses arising almost yearly. These include X-ray quasi-periodic eruptions (QPEs), ambiguous and extreme nuclear transients (ANTs & ENTs), or new modes of AGN activity, such Bowen fluorescence flares (BFFs) and changing-look AGN (CLAGN). All of these exotic transients offer a unique glimpse into the dynamics of galactic nuclei and the physics of SMBHs. Given their relatively recent discovery and intrinsic rarity, their potential has yet to be fully explored, but they promise to offer new insights into the rates of stellar encounters with SMBHs and the efficiency of SMBH accretion.
Despite advances, several theoretical challenges remain in modelling these events and explain their multi-wavelength, multi-mode (polarimetry) and multi-messenger properties.. Building strong collaborations and encouraging discussions between the observational and theoretical nuclear transient communities will bridge this gap. The aim of this Special Session is to bring these groups together to better understand the nature of these events and the intricate connection between the physics and rates of nuclear transients and the evolution of galaxies and SMBHs. With the imminent arrival of new observational facilities, particularly LSST, and later LISA, we are on the brink of a discovery era for nuclear transients, bringing new insights into black hole demographics and the evolution of galaxies over cosmic time.
Programme
- Session 1: Tidal Disruption Events
- Session 2: Ambiguous/Extreme Nuclear Transients, Bowen Fluorescence Flares, Changing Look AGN
- Sessions 3&4: Repeating Nuclear Transients, Quasi-Periodic Eruptions/Outflows, Extreme Mass Ratio Inspirals
Invited speakers
- Brenna Mockler (Carnegie Observatories, USA)
- Phil Wiseman (University of Southampton, UK)
- Joheen Chakraborty (MIT, USA)
- Paula Sánchez Sáez (ESO Garching, Germany)
Scientific organisers
- Panos Charalampopoulos (Chair) (University of Turku, Finland)
- Charlotte Angus (co-Chair) (Queen's University Belfast, UK)
- Jane Lixin Dai (University of Hong Kong,China)
- Decker French (University of Illinois, USA)
- Giorgos Leloudas (DTU Space, Denmark)
- Matt Nicholl (Queen's University Belfast, UK)
- Yuhan Yao (University of California, Berkeley, USA)
- Petra Suková (AsU CAS, Czech Republic)
- Francesco Tombesi (Tor Vergata University of Rome, Italy)
- Michal Zajacek (Masaryk University, Czech Republic)
- Dheeraj R. Pasham (MIT, USA)
A power cut will shut down all EAS services on Tuesday, 10 January 2017 starting at 7:30 CET.
