The next SFB-colloquium will be on June 17 at 2 pm in the Lecture Hall III of the Physics Institutes in Cologne.
Shmuel Bialy from the European Southern Observatory, Santiago, Chile will talk about “How stars shape Interstellar Gas via: Supernova, Cosmic-rays, and Turbulence“.
Cosmic Rays —
Stars form within dense molecular gas, where cosmic rays (CRs) regulate ionization, chemistry, and magnetic coupling. Yet measuring the CR ionization rate (ζ) in these environments has remained a persistent challenge. I will present recent JWST observations of the starless core Barnard 68, revealing the first direct detection of CR-excited H₂ emission—a long-predicted but previously undetected signature. This allows a direct measurement of ζ, establishing molecular clouds as vast, naturally occurring CR detectors floating in space.
Supernovae —
In the second part of the talk, I will shift gears to the large-scale structure of the ISM, highlighting how 3D dust maps uncover hidden features such as the recently identified “PerTau shell.” I will discuss the implications of such expanding shells for ISM dynamics and their potential role in driving turbulence and accelerating CRs.
(Cologne, Host Stefanie Walch-Gassner)