18 février 2020Accretion-driven outbursts in the context of massive star formation

Dominique Meyer, Institut für Astronomie und Astrophysik, Universität Tübingen

Accretion-driven luminosity outbursts are a vivid manifestation of variable mass accretiononto protostars. They are known as the so-called FU Orionis phenomenon in the context oflow-mass protostars. More recently, this process has been found in models of primordial starformation. Using numerical radiation hydrodynamics simulations, we stress that present-dayforming massive stars also experience variable accretion and show that this process is accompanied by luminous outbursts induced by the episodic accretion of gaseous clumps falling from the circumstellar disk onto the protostar. Consequently, the process of accretion-induced luminous flares is also conceivable in the high-mass regime of star formation and we propose to regard this phenomenon as a general mechanism that can affect protostars regardless of their mass and/or the chemical properties of the parent environment in which they form. In addition to the commonness of accretion-driven outbursts in the star formation machinery, we conjecture that luminous flares from regions hosting forming high-mass star may be an observational implication of the fragmentation of their accretion disks.