2009/10/20 by Nickolas Moeckel, Henry B. Throop
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Debris disk #Intermediate polar #Planet #Planetary system #Protoplanetary disk #Protostar #Star formation #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/707/1/268
published as Astrophys.J.707:268-277,2009 · Accepted to ApJ. Version 2 replaces a mislabeled figure. Animations of the simulations and a version of the paper with slightly less-compressed images can be found at http://origins.colorado.edu/~moeckel/BHLpaper
arxiv created 2009/10/20 · openalex publication_date 2009/11/19 · arxiv updated 2014/11/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Young stellar systems orbiting in the potential of their birth cluster can accrete from the dense molecular interstellar medium during the period between the star's birth and the dispersal of the cluster's gas. Over this time, which may span several Myr, the amount of material accreted can rival the amount in the initial protoplanetary disk; the potential importance of this "tail-end" accretion for planet formation was recently highlighted by Throop & Bally. While accretion onto a point mass is successfully modeled by the classical Bondi–Hoyle–Lyttleton solutions, the more complicated case of accretion onto a star–disk system defies analytic solution. In this paper, we investigate via direct hydrodynamic simulations the accretion of dense interstellar material onto a star with an associated gaseous protoplanetary disk. We discuss the changes to the structure of the accretion flow caused by the disk, and vice versa. We find that immersion in a dense accretion flow can redistribute disk material such that outer disk migrates inward, increasing the inner disk surface density and reducing the outer radius. The accretion flow also triggers the development of spiral density features, and changes to the disk inclination. The mean accretion rate onto the star remains roughly the same with and without the presence of a disk. We discuss the potential impact of this process on planet formation, including the possibility of triggered gravitational instability, inclination differences between the disk and the star, and the appearance of spiral structure in a gravitationally stable system.