May 2026
Following Tracer Particles to Identify Filaments in Star-Forming Cores with HDBSCAN (Nuray Ortaköse)
Impact of Radiation Pressure and Ionizing Radiation Feedback in a Turbulent, Magnetized, Self-Gravitating, Massive Core-Collapse
Birka Zimmermann
One of the largest unresolved problems in modern star formation is that of the formation of massive stars. Lower mass stars can primarily be explained due to the interplay of gravity, turbulence and thermal pressure leading to quasi-Jeans mass fragmentation; however, additional support against gravity is necessary for the formation of higher mass stars. This is thought to come primarily from magnetic fields and radiative feedback. High mass stars are also thought to evolve faster and start nuclear burning before the mass accretion process is finished, thus feedback and accretion happen at the same time.
We perform simulations with the magneto-hydrodynamic code FLASH which we have expanded to treat complex physical processes, including thermal and ionizing radiative feedback, essential to model high-mass star formation.
One of our simulations is shown in Fig. 1, where we present the collapse of a subvirial, 1000 M☉ core with an initial radius of 1 pc and a linear magnetic field of 100 μG. Molecular Hydrogen is colored in orange, atomic Hydrogen in blue and ionized Hydrogen in red. During the collapse a sheet-like structure perpendicular to the magnetic field is formed. In the swept up material dense cores of around 10 M☉ are launched. After 0.7 tff outflows along the magnetic field lines are ejected and after 0.9 tff a HII region in the center appears.
Monthly Highlights
April 2026
Estimating ionization fractions in SILCC simulations (Lennart Buhlmann)
March 2026
1D protostellar disk sub-grid model for star formation 3D MHD simulations (Anaïs Pauchet)
January 2026
Protostellar Outflows: From Simulations to Synthetic Observations (Taishi Ushirogi)
December 2025
Prestellar Core Formation in Colliding Gas Flows: Simulations and Synthetic Observations (Felix Rauprich)
November 2025
Measuring the Velocity Dispersion of the Warm Neutral Medium of the Milky Way at Galactic Scale using the Code FLASH (Wajdee Chayeb)
October 2025
Higher-order finite volume method for modelling shock waves in the interstellar medium (Mervin Yap)
June 2025
Simulating [CII] emission in high-redshift galaxies and their halos (Clarissa Immisch)
May 2025
Episodic Accretion onto Low Mass Protostars (Christian Riesop)
April 2025
Molecular cloud formation: Impact of metallicity, far-UV and CR heating using SILCC-Zoom simulations (Sanjit Pal)
March 2025
Modelling Protostellar Outflows in ISM Simulations (Michael Weis)
February 2025
Multi-band ray-tracing of ionizing photons (Sebastian Vider)
December 2024
Simulating the ISM and its processes (Sebastian Vider)