Physikalische Kolloquien im Wintersemester 2025/26

Prof. Dr. Günther Hasinger
Deutsches Zentrum für Astrophysik, Technische Universität Dresden, DESY Zeuthen

Cosmic Multimessenger Signals and the German Center for Astrophysics

The addition of gravitational wave measurements to the classical electromagnetic astronomy has opened a vast new area of exciting scientific studies – bringing sound to the cosmic movies. In addition, other information carriers like extreme energy cosmic rays, neutrinos, and even whole stellar systems can be used to derive physical information about the dark sector of the Universe. This field is dominated by the ecosystem of compact objects, in particular neutron stars and black holes of all sizes. The presentation reviews some of the most exciting recent developments in this field. This is the scientific arena for the German Center for Astrophysics (Deutsches Zentrum für Astrophysik – DZA), which aims to become one of the largest centers of multimessenger astrophysics in the world. Combining astrophysics, technology development and data science in an integrated approach, the center aims to have a transformative effect on the region in central Europe.

Dr. Alison Mitchell
FAU Erlangen-Nürnberg

Galactic gamma-ray astronomy: novae, supernova remnants and pulsar wind nebulae

Astrophysical gamma-rays at photon energies above a few GeV are produced by non-thermal processes involving cosmic ray interactions. These cosmic rays are accelerated to high energies within our galaxy at astrophysical shocks, which arise in various environments. In this talk, I will give a brief introduction to gamma-ray astronomy and highlight examples of different source classes. Supernova remnants and pulsar wind nebulae are among the most numerous and powerful of known galactic gamma-ray emitters, reaching photon energies up to ~PeV. Gamma-ray emission from Novae, however, is transient in nature and reaches energies up to ~TeV. These maximum energies were found in 2021-2022, and I will place particular emphasis on recent results and future directions in this talk.

Dr. Friedrich König
St. Andrews University 

Analogue gravity experiments with light in optical fibres

Analogue gravity aims to mimic physical processes that occur in the interplay between general relativity and field theory in a controlled laboratory environment. The goal is to gain insights into phenomena that are hard or impossible to observe in a purely gravitational context, i.e. in astrophysics. These are in particular situations of strong gravitational interactions, important quantum effects, or extreme length scales. In this talk I will describe how ultrashort optical pulses in fibres can generate an analogue of the event horizon and lead to the observation of the analogue Hawking effect [1]. In another approach, wave emission from the light ring of a black hole, as observed in the LIGO collaboration, can be modelled with a fibre optical analogue [2].

[1] Philbin et al., Science 319,1367-1370 (2008).
[2] Burgess et al.. Phys. Rev. Lett. 132, 053802 (2024).