Abstract

Invited Talk - Plenary

Friday, 19 September 2025, 09:00   (Synagoge - Kuppelsaal / virtual plenum)

Time domain sky signals with information field theory

Torsten Enßlin
Deutsches Zentrum für Astrophysik

Exploring the time-dependent astronomical sky enables us to study the energetic processes occurring in and around compact objects. Imaging these environments poses a challenge to traditional methods, which are usually designed for a static sky. The additional time dimension exacerbates the issues of data sparsity (not every location is monitored at all times), noise (there is no co-adding of repeated measurements) and calibration (did the source or the instrument flicker?).
Information field theory (IFT), a mathematical formalism for probabilistic field inference, can help overcome these issues. Methods based on IFT can learn spatial, spectral and temporal correlations from data and exploit these for spatio-spectro-temporal imaging and calibration.
This talk will present the basic idea of IFT and existing astrophysical applications to time-domain signals from magnetars, black holes and radio galaxies. It will also highlight the future prospects of IFT for exoplanet searches and for understanding the dynamics of observed systems.
Finally, the Universal Bayesian Imaging Kit (UBIK) is presented as highly configurable open-source software that enables imaging with an growing number of instruments. Time-domain imaging with UBIK will be enabled at the German Center for Astrophysics (DZA).