Disks around Brown Dwarfs in the Ejection Scenario. I. Disk Collisions in Triple Systems

• Published in: The Astrophysical journal Vol. 743; no. 2; pp. 106 - jQuery1323900236442='48'
• Main Authors: Umbreit, Stefan, Spurzem, Rainer, Henning, Thomas, Klahr, Hubert, Mikkola, Seppo
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 20.12.2011; IOP
• Subjects: Astronomy; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Earth, ocean, space; Exact sciences and technology; MASS; MATTER; PROTOPLANETS; STAR EVOLUTION; STARS; TWO-BODY PROBLEM; Circumstellar matter; Triple collision; Stellar kinematics; Statistical study; Planetary system; Proto planetary nebula; Celestial mechanics; brown dwarfs; planetary systems; Star formation; Low-mass stars; Brown dwarf stars; stars: kinematics and dynamics; Models; protoplanetary disks - stars: formation; stars: low-mass; Stellar dynamics
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/743/2/106

We investigate the fate of disks around brown dwarfs in the ejection scenario and the implications on their observable properties. For that purpose, a parameter study of close triple approaches leading to escape is carried out where the ejected body is surrounded by a low-mass disk. We analyze the recircularized radial surface density profile of the post-encounter disk in dependence of the minimum two-body distances between the escaper and the perturbing bodies. Our results show that the general appearance of the disks is rather similar to disks after two-body encounters in as much as there is also an exponential drop in surface density for the outer disk regions as well as an enhancement of surface density for the innermost region relative to the initial disk profile. However, the disks after close triple approaches are mostly less massive, have generally flatter recircularized surface density disk profiles, and have radii that are similar or larger compared to disks after two-body encounters. From our results, we construct a simple scale-free model only depending on the minimum encounter distances of the two perturbers. Such a model is especially useful for statistical studies of disk collisions in triple systems that must cover a large range of encounter distances.