In B6 we investigate the formation and evolution of massive star habitats for different environmental conditions typically found across Cosmic Time by means of 3D MHD simulations with our extended multi-physics simulation framework which is based on the adaptive mesh refinement code FLASH. This is done on larger scales (∽1-few kpc) to probe different galactic environments as well as on smaller scales by zooming into the forming molecular clouds where massive star formation is about to take place. On larger scales we inform our simulations from observations of nearby galaxies as well simulations of galaxy evolution. On smaller scales, we aim to deliver knowledge on the mass and energy flowing from large to small scales and feeding pc-scale massive star habitats as studied in project area A. For example, we will be able to answer the questions whether, on any particular scale, the massive star habitats dynamically decouple from the respectively larger scale. We will also be able to address the importance of external (galactic environment such as spiral arm potential or merger, high radiation environment near a Galactic Center etc) vs. internal properties (turbulence, sub-structure, magnetic field strength) for evaluating which conditions promote or hinder massive star formation. Since the many physical processes which shape the multi-phase interstellar medium interact in a non-linear way, this evaluation is non-trivial. By improving our simulation code further to include the radiative transfer of cooling radiation from hot, stellar feedback-driven bubbles, we will add a unique aspect to such simulations of the multi-phase interstellar medium. We expect the latter aspect to be of particular importance for dense and gas- rich environments, where massive stars are preferentially forming. The dynamics of the gas might be completely altered in these environments, where the re-radiated photons are again re-absorbed, boosting the energy footprint of massive star feedback. Over the next twelve years, B6 aims to show whether a universal star formation process is feasible given the variety of galactic environments, and which physical processes are responsible for it after all.
Publications
2025
Rathjen, Tim-Eric; Walch, Stefanie; Naab, Thorsten; Nürnberger, Pierre; Wünsch, Richard; Seifried, Daniel; Glover, Simon C. O.
@article{2025MNRAS.540.1462R,
title = {SILCC – VIII. The impact of far-ultraviolet radiation on star formation and the interstellar medium},
author = {Tim-Eric Rathjen and Stefanie Walch and Thorsten Naab and Pierre Nürnberger and Richard Wünsch and Daniel Seifried and Simon C. O. Glover},
doi = {10.1093/mnras/staf792},
year = {2025},
date = {2025-06-01},
journal = {Monthly Notices of the RAS},
volume = {540},
number = {2},
pages = {1462-1490},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{2025A&A...694A..69H,
title = {Emergence of high-mass stars in complex fiber networks (EMERGE): V. From filaments to spheroids: the origin of the hub-filament systems},
author = {A. Hacar and R. Konietzka and D. Seifried and S. E. Clark and A. Socci and F. Bonanomi and A. Burkert and E. Schisano and J. Kainulainen and R. Smith},
doi = {10.1051/0004-6361/202450779},
year = {2025},
date = {2025-02-01},
urldate = {2025-02-01},
journal = {A&A},
volume = {694},
pages = {A69},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{2025MNRAS.537..482B,
title = {The impact of cosmic-ray heating on the cooling of the low-metallicity interstellar medium},
author = {Vittoria Brugaletta and Stefanie Walch and Thorsten Naab and Philipp Girichidis and Tim-Eric Rathjen and Daniel Seifried and Pierre Colin Nürnberger and Richard Wünsch and Simon C. O. Glover},
doi = {10.1093/mnras/staf039},
year = {2025},
date = {2025-02-01},
journal = {Monthly Notices of the RAS},
volume = {537},
number = {1},
pages = {482-499},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{2024A&A...692A..58E,
title = {The origin and evolution of the [CII] deficit in HII regions and star-forming molecular clouds},
author = {S. Ebagezio and D. Seifried and S. Walch and T. G. Bisbas},
doi = {10.1051/0004-6361/202449682},
year = {2024},
date = {2024-12-01},
urldate = {2024-12-01},
journal = {A&A},
volume = {692},
pages = {A58},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{2024A&A...690A.348C,
title = {JWST MIRI and NIRCam observations of NGC 891 and its circumgalactic medium},
author = {Jérémy Chastenet and Ilse De Looze and Monica Relaño and Daniel A. Dale and Thomas G. Williams and Simone Bianchi and Emmanuel M. Xilouris and Maarten Baes and Alberto D. Bolatto and Martha L. Boyer and Viviana Casasola and Christopher J. R. Clark and Filippo Fraternali and Jacopo Fritz and Frédéric Galliano and Simon C. O. Glover and Karl D. Gordon and Hiroyuki Hirashita and Robert Kennicutt and Kentaro Nagamine and Florian Kirchschlager and Ralf S. Klessen and Eric W. Koch and Rebecca C. Levy and Lewis McCallum and Suzanne C. Madden and Anna F. McLeod and Sharon E. Meidt and Aleksandr V. Mosenkov and Helena M. Richie and Amélie Saintonge and Karin M. Sandstrom and Evan E. Schneider and Evgenia E. Sivkova and J. D. T. Smith and Matthew W. L. Smith and Arjen Wel and Stefanie Walch and Fabian Walter and Kenneth Wood},
doi = {10.1051/0004-6361/202451033},
year = {2024},
date = {2024-10-01},
urldate = {2024-10-01},
journal = {A&A},
volume = {690},
pages = {A348},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{2024MNRAS.532.1262W,
title = {Properties of molecular clumps and cores in colliding magnetized flows},
author = {M. Weis and S. Walch and D. Seifried and S. Ganguly},
doi = {10.1093/mnras/stae1518},
year = {2024},
date = {2024-08-01},
journal = {Monthly Notices of the RAS},
volume = {532},
number = {2},
pages = {1262-1295},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
@article{2024MNRAS.528.3630G,
title = {SILCC-Zoom: the dynamic balance in molecular cloud substructures},
author = {Shashwata Ganguly and S. Walch and S. D. Clarke and D. Seifried},
doi = {10.1093/mnras/stae032},
year = {2024},
date = {2024-02-01},
urldate = {2024-02-01},
journal = {Monthly Notices of the RAS},
volume = {528},
number = {2},
pages = {3630-3657},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gatto, Walch, Naab, Girichidis, Wünsch, Glover, Klessen, Clark, et al., “The SILCC project – III. Regu- lation of star formation and outflows by stellar winds and supernovae”, MNRAS 466, 1903 (2017).
Girichidis, Walch, Naab, Gatto, Wünsch, Glover, Klessen, Clark, et al., “The SILCC (SImulating theLifeCycle of molecular Clouds) project – II. Dynamical evolution of the supernova-driven ISM and thelaunching of outflows”, MNRAS 456, 3432 (2016).
Haid, Walch, Seifried, Wünsch, Dinnbier, and Naab, “SILCC-Zoom: The early impact of ionizing radia-tion on forming molecular clouds”, MNRAS 482, 4062 (2019).
Haid, Walch, Seifried, Wünsch, Dinnbier, and Naab, “The relative impact of photoionizing radiation andstellar winds on different environments”, MNRAS 478, 4799 (2018).
Mackey, Walch, Seifried, Glover, Wünsch, and Aharonian, “Non-equilibrium chemistry and destructionof CO by X-ray flares”, MNRAS 486, 1094 (2019).
Seifried, Walch, Girichidis, Naab, Wünsch, Klessen, Glover, Peters, et al., “SILCC-Zoom: the dynamicand chemical evolution of molecular clouds”, MNRAS 472, 4797 (2017).
Walch, Girichidis, Naab, Gatto, Glover, Wünsch, Klessen, Clark, et al., “The SILCC (SImulating theLifeCycle of molecular Clouds) project – I. Chemical evolution of the supernova-driven ISM”, MNRAS454, 238 (2015).
Walch, Whitworth, Bisbas, Wünsch, and Hubber, “Clumps and triggered star formation in ionizedmolecular clouds”, MNRAS 435, 917 (2013).
Wünsch, Walch, Dinnbier, and Whitworth, “Tree-based solvers for adaptive mesh refinement codeFLASH – I: gravity and optical depths”, MNRAS 475, 3393 (2018).
Working group ogrzanizers: Chinmaya Nagar, Divita Gupta, Ina Galić, Masato Kobayashi, Simon Dannhauer, Vittoria Brugaletta, Wonju Kim, and Zein Bazzi
Achievement and progress report from SFB working groups.
13:45 – 14:00
Planning of discussion rounds
14.00 – 15.00
Student Meeting (incl. Student Council)
PI meeting
Discussion groups
Discussion groups
15:00 – 16:00
Discussion groups
PI meeting
Discussion groups
Discussion groups
16:00 – 16:30:00
Coffee break
Chair:
16.00 – 16.25
Petra Fackendahl, Isabelle Breloy
Report from TP Z & Financial
16:30 – 17:50
all
Discussion groups
Discussion groups
Discussion groups
Discussion groups
18.00
Dinner
Day 2
26.03.2025
Lecture Hall
seminar room 1
seminar room 2
seminar room3
08.00 – 09.00
Breakfast
Chair:
9:00 – 9:30
TBD
Wrap up of day 1, results of discussion groups
9:30 – 10:00
Discussion groups
Sustainability Board Meeting
Diversity Board Meeting
Executive Board Meeting
10:00 – 10:30
Discussion groups
Discussion groups
Discussion groups
10:30 – 11:00
Coffee Break
11.00-15.00
Hiking
Chair: Dominik Riechers
15:00 – 16:00
all
Poster presentations (2min)
16:00 – 17:00
Coffee Break & Poster reception
17:00 – 18:30
all
Discussion groups
Discussion groups
Discussion groups
Discussion groups
19:00 – 24:00
Dinnerparty
Day 3
27.03.2025
Lecture Hall
08.00 – 09.00
Breakfast
Chair:
9:00 – 10:30
TBD
Wrap up of day 2, results of discussion groups
10.30 – 11.00
Coffee Break
Chair:
11.00 – 11.15
Report by the Sustainability Board
11.15 – 11.30
Report by the Student Council
11.30 – 11.45
Report by the Diversity Board
12:10 – 12:25
Summary
12.30 – 13.30
Lunchbuffet
13.30 – 15.30
Members Assembly (obligatory)
16:00
Departure
Project Area C
The observational projects C1 to C3 and related theory projects C5 and C6 cover observations of the habitats of massive stars from tens of parsec to Mpc scales in “typical”, starburst, and AGN host galaxies over 13 billion years of the history of the universe, critically complementing the other project areas in scales, diversity of environments, and cosmic time. A combination of the most sensitive facilities like ALMA and JWST with new wide-field observatories like FYST/CCAT-prime make it possible to reach both the level of detail and statistical robustness to push these studies to the next level. To prepare for the future, critical detector and readout technology development is delivered by projects C7 and C8, as necessary to build a new generation of instruments that speed up the FYST/CCAT-prime surveys in C2 and C3 by an order of magnitude in the later funding phases. In tandem with these developments, the laboratory spectroscopy and modelling of molecular ions done in C4 are critical to fully exploit a suite of new key tracers of massive star-forming environments in the Early Universe, as targeted in C1.
Image credits: C3/C6 from Karoumpis et al. 2022; C4 from Töpfer et al. 2020; C7 provided by N. Honingh; C8 from Klein et al. 2012; Galaxy composite for C1, C2 and C5 is a composite image of NGC 628 with ALMA (orange) and Hubble (blue) data provided by NRAO/AUI/NSF, B. Saxton: ALMA (ESO/NAOJ/NRAO), NASA/Hubble; for the connection to project areas A and B we show Orion.
Project Area B
B studies the habitats of massive stars on galactic scales. We show a portion of the Galactic disc plane as observed with Spitzer in purple and with ATLASGAL in orange and the corresponding molecular clouds identified in SEDIGISM (credit: Wyrowski; Duarte-Cabral et al. 2021) showcasing the Milky Way part of projects B1 & B2. In B1, parsec-scale observations of Milky Way massive clumps are combined with synthetic observations based on high-resolution simulations7. In B2, high-feedback regions are studied (credit: Simon). B3 will study massive star habitats in nearby galaxies (credit: Bigiel/PHANGS). B2 and B3 make use of the new CHAI instrument to be installed at FYST/CCAT-prime. The low-frequency channel of CHAI is used to study the whole Galactic disc, the Magellanic Clouds, and nearby galaxies in CO (J = 4 – 3) and [CI]. The high-frequency channel of CHAI is developed in the first CRC funding period in B7 (credit: Graf/Honingh). B4 studies the impact of magnetic fields in different environments using different techniques (e.g. dust polarisation; the synthetic map shown is taken from Seifried et al. 2019). B5 studies the late stages of massive star habitats (supernova remnants) using a new combination observations towards pulsar sight- lines (credit: Yao et al. 2021) with state-of-the-art simulations of the multi-phase interstellar medium that include supernovae (see also B6; credit: Walch; Rathjen et al. 2021). In B8, the (far-)infrared spectra of molecular anions (e.g. PAHs) are recorded in the laboratory in order to better constrain the observed emission of massive star habitats (credit: Schlemmer)
Image credits: B1 background: ESO/APEX/ATLASGAL consortium/NASA/GLIMPSE consortium/ESA/Planck.
Project Area A
Habitats of massive stars at high resolution. We combine different methodological pillars. Three observational projects study different phases of massive star formation at high resolution. We include hot molecular cores (A1), massive star formation in different galactic habitats (A2), and the infrared view on massive stars in different environments (A3). These observational efforts are combined with laboratory astrophysics (A4) measuring the spectra of complex molecules and high-resolution 3D simulations of massive star formation and star cluster evolution (A5), as well as detailed modelling of PDRs and dust (A6) needed to interpret the observations.
Image credits: background: Gaia’s view of the Milky Way (credit: ESO/Gaia/DPAC). Foreground: (A1, A2 and A4) ALMA emission spectrum of a hot core and a synthetic, laboratory-based spectrum mirrored in absorption (credit: Endres et al. 2021); (A1) image of the Large Magellanic Cloud (LMC), with the zoom-in showing the ALMA 1.3 mm continuum emission of a cluster-forming region in the LMC (credit: Hamedani Golshan); (A2) ALMA observations of a super-stellar cluster progenitor in Sgr B2 with converging dense filaments and an expanding molecular outflow (credit: Schwörer, Sánchez-Monge); (A3) collage of massive star binaries in Orion (credit: GRAVITY collaboration, M. Karl); (A5) massive star formation simulation with the MHD code FLASH (credit: Klepitko, Walch); (A6) Orion Bar in HCO+ with PDR model description (credit: Röllig, Ossenkopf-Okada).
image credit
1_SFB2023_overview_title_asm: SgrB2: Schwörer, Sánchez-Monge (A); Orion KL: Bally et al. 2017 (A); M16: NASA, Jeff Hester, and Paul Scowen (Arizona State University) (A-B); Crab nebula: NASA, ESA, J. Hester and A. Loll (Arizona State University) (B); Antennae: ALMA (ESO/NAOJ/NRAO). Visible light image: the NASA/ESA Hubble Space Telescope (A); M82: NASA/JPL-Caltech/STScI/CXC/UofA/ESA/AURA/JHU (B-C); Universe: J.Neidel/J.Onorbe/MPIA (C).
