Heidelberg 2022 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 1: Astrophysics
EP 1.6: Vortrag
Montag, 21. März 2022, 15:30–15:45, EP-H1
Modeling disk fragmentation and multiplicity in massive star formation — •Rolf Kuiper1 and André Oliva2 — 1Universität Heidelberg — 2Universität Tübingen
There is growing evidence that massive stars grow by disk accretion in a similar way to their low-mass counterparts. Early in evolution, these disks can achieve masses that are comparable to the current stellar mass, and therefore the forming disks are highly susceptible to gravitational fragmentation. We investigate the formation and early evolution of an accretion disk around a forming massive protostar, focussing on its fragmentation physics.
We used a grid-based, self-gravity radiation hydrodynamics code including a sub-grid module for stellar evolution and dust evolution. We purposely do not use a sub-grid module for fragmentation such as sink particles to allow for all paths of fragment formation and destruction, but instead we keep the spatial grid resolution high enough to properly resolve the physical length scales of the problem, namely the pressure scale height and Jeans length of the disk.
The cloud collapses and a massive (proto)star is formed in its center surrounded by a fragmenting Keplerian-like accretion disk with spiral arms. The fragments have masses of ~1 Msol, and their continuous interactions with the disk, spiral arms, and other fragments result in eccentric orbits. Fragments form hydrostatic cores surrounded by secondary disks with spiral arms that also produce new fragments. Based on this, we study the multiplicity from spectroscopic multiples to companions at distances at 1000 au.