AFFIRM MASS - Accretion Flows and Feedback In Realistic Models of MASsive Star formation

• Applicant: Professor Dr. Rolf Kuiper
• Subject Area: Astrophysics and Astronomy
• Term: from 2014 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 259131583

• Final Report Year: 2023

Final Report Abstract

Frankly speaking, I dare to say that the Emmy Noether Research Group has been a complete success, both from the point of view of the results of the individual scientific projects and for the associated careers of the project participants. We proposed to investigate the physics which govern the upper mass limit of stars in the present-day universe. From our results up to now, we can already exclude disk fragmentation, protostellar outflows, and photoionization feedback and HII regions to be the limiting factors. Our results clearly demonstrate that continuum radiation forces intrinsically constrain the final mass of a forming high-mass star. Line-driven radiation forces denote an interesting supplement to the final picture of accreting massive stars and our numerical investigations on these near star feedback physics even include the metallicity dependence of the resulting intrinsic upper mass limit. Major breakthroughs in terms of advances in numerical methods and simulation accomplishment could be achieved via (a) first simulation of high-mass accretion disks on AMR grids which include the effect of the disk’s shear on the final fragmentation, (b) highest spatial resolution simulations of fragmenting accretion disks around massive protostars up to date, (c) first simulations of the formation of massive stars which include radiation forces and photoionization feedback simultaneously, based on the development of a new hybrid scheme for EUV radiation transport, (d) first convergence study of magnetized high-mass pre-stellar core collapse, recently followed up by a large simulation series to explore the broad parameter space of initial conditions as well as a comparison to the highest-resolution observations to date, and (e) first simulations of the formation of Larson’s first and second core properties in the high-mass star formation regime.

Publications

• PROTOSTELLAR OUTFLOWS AND RADIATIVE FEEDBACK FROM MASSIVE STARS. II. FEEDBACK, STAR-FORMATION EFFICIENCY, AND OUTFLOW BROADENING. The Astrophysical Journal, 832(1), 40.
  Kuiper, Rolf; Turner, Neal J. & Yorke, Harold W.
  
• Forming spectroscopic massive protobinaries by disc fragmentation. Monthly Notices of the Royal Astronomical Society, 473(3), 3615-3637.
  Meyer, D. M.-A.; Kuiper, R.; Kley, W.; Johnston, K. G. & Vorobyov, E.
  
• First core properties: from low- to high-mass star formation. Astronomy & Astrophysics, 618, A95.
  Bhandare, Asmita; Kuiper, Rolf; Henning, Thomas; Fendt, Christian; Marleau, Gabriel-Dominique & Kölligan, Anders
  
• First hydrodynamics simulations of radiation forces and photoionization feedback in massive star formation. Astronomy & Astrophysics, 616, A101.
  Kuiper, R. & Hosokawa, T.
  
• Jets and outflows of massive protostars. Astronomy & Astrophysics, 620, A182.
  Kölligan, A. & Kuiper, R.
  
• Line-driven ablation of circumstellar discs – III. Accountingfor and analysing the effects of continuum optical depth. Monthly Notices of the Royal Astronomical Society, 479(4), 4633-4641.
  Kee, Nathaniel Dylan; Owocki, Stanley & Kuiper, Rolf
  
• Line-driven ablation of circumstellar discs – IV. The role of disc ablation in massive star formation and its contribution to the stellar upper mass limit. Monthly Notices of the Royal Astronomical Society, 483(4), 4893-4900.
  Kee, Nathaniel Dylan & Kuiper, Rolf
  
• Birth of convective low-mass to high-mass second Larson cores. Astronomy & Astrophysics, 638, A86.
  Bhandare, Asmita; Kuiper, Rolf; Henning, Thomas; Fendt, Christian; Flock, Mario & Marleau, Gabriel-Dominique
  
• Makemake + Sedna: A Continuum Radiation Transport and Photoionization Framework for Astrophysical Newtonian Fluid Dynamics. The Astrophysical Journal Supplement Series, 250(1), 13.
  Kuiper, Rolf; Yorke, Harold W. & Mignone, Andrea
  
• Modeling disk fragmentation and multiplicity in massive star formation. Astronomy & Astrophysics, 644, A41.
  Oliva, G. André & Kuiper, R.