2006/07/06 by Eduard I. Vorobyov, E. I. Vorobyov, Shantanu Basu · 8 citations
Physics and Astronomy · #Accretion (finance) #Angular momentum #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Burst mode (computing) #Gravitational instability #Physics #Planet #Protoplanetary disk #Protostar #Star formation #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/507320
published as Astrophys.J.650:956-969,2006 · 39 pages, 14 figures, aastex; will appear in ApJ 20 Oct 2006; version with higher resolution figures available at http://www.astro.uwo.ca/~basu/pb.htm
arxiv created 2006/07/06 · openalex publication_date 2006/10/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present new numerical simulations in the thin disk approximation that characterize the burst mode of protostellar accretion. The burst mode begins upon the formation of a centrifugally balanced disk around a newly formed protostar. It comprises prolonged quiescent periods of low accretion rate (typically ≲10 -7 M ☉ yr -1 ) that are punctuated by intense bursts of accretion (typically ≳10 -4 M ☉ yr -1 , with duration ≲100 yr) during which most of the protostellar mass is accumulated. The accretion bursts are associated with the formation of dense protostellar/protoplanetary embryos, which are later driven onto the protostar by the gravitational torques that develop in the disk. Gravitational instability in the disk, driven by continuing infall from the envelope, is shown to be an effective means of transporting angular momentum outward and mass inward to the protostar. We show that the disk mass always remains significantly less than the central protostar's mass throughout this process. The burst phenomenon is robust enough to occur for a variety of initial values of rotation rate and frozen-in (supercritical) magnetic field and a variety of density-temperature relations. Even in cases where the bursts are nearly entirely suppressed, a moderate increase in cloud size or rotation rate can lead to vigorous burst activity. We conclude that most (if not all) protostars undergo a burst mode of evolution during their early accretion history, as inferred empirically from observations of FU Orionis variables.