Shaping the Kuiper belt size distribution by shattering large but strengthless bodies

By M. Pan, R. Sari. 2004

139 citations recorded by the source corpus.

The observed size distribution of Kuiper belt objects (KBOs)—small icy and rocky Solar System bodies orbiting beyond Neptune—is well described by a power law at large KBO sizes. However, recent work by Bernstein et al. (2004, Astron. J. 128, 1364–1390) indicates that the size distribution breaks and becomes shallower for KBOs smaller than about 70 km in size. Here we show that we expect such a break at KBO radius ∼40km since destructive collisions are frequent for smaller KBOs. Specifically, we assume that KBOs are gravity-dominated bodies with negligible material strength. This gives a power-law slope q ≃ 3 where the number N_(>r) of KBOs larger than a size r is given by N_(>r)∝r^(1−q); the break location follows from this slope through a self-consistent calculation. The existence of this break, the break's location, and the power-law slope we expect below the break are consistent with the findings of Bernstein et al. (2004, Astron. J. 128, 1364–1390). The agreement with observations indicates that KBOs as small as ∼40km are effectively strengthless.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/07003b49f563dbbeaa1ef384fc77b33a81e9bff9

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In Astronomy and Astrophysics

Citations in the corpus

Forming Planetesimals in Solar and Extrasolar Nebulae (2009, background): “While the feedback of solids on gas triggers vertical shear instabilities that obstruct self-gravity, this same feedback triggers streaming instabilities that strongly concentrate particles.”
Asteroids Were Born Big (2009, background): “, 2004) is also a signature of accretion and not one of collisional grinding, unlike what it is usually assumed (e.g. Kenyon and Bromley, 2004; Pan and Sari, 2005).”
TOWARD A DETERMINISTIC MODEL OF PLANETARY FORMATION. VI. DYNAMICAL INTERACTION AND COAGULATION OF MULTIPLE ROCKY EMBRYOS AND SUPER-EARTH SYSTEMS AROUND SOLAR-TYPE STARS (2010, background): “If these planetesimals have sizes larger than a few km (as in the Kuiper Belt, e.g., Pan & Sari 2005), their velocity dispersion would exceed that for disruptive collisions (Stewart & Leinhardt 2009).”
Variations on Debris Disks: Icy Planet Formation at 30-150 AU for 1-3 M☉ Main-Sequence Stars (2008, background): “To check how the evolution of the small planetesimals depends on Q d , we consider a broad range in the bulk component of the strength, Qb ¼ 1Y105 ergs g 1 with b ¼ 0 (Pan & Sari 2005; Kenyon & Bromley 2004c, 2005; Kenyon et al. 2008).”
Dust Dynamics, Surface Brightness Profiles, and Thermal Spectra of Debris Disks: The Case of AU Microscopii (2005, background): “…on low-eccentricity orbits whose collisional strengths are independent of size, whose AU Mic Disk 5 spatial distribution is homogeneous, and whose numbers are maintained in a purely collisional equilibrium, as first derived by Dohnanyi (1969; see also O’Brien & Greenberg 2003; Pan & Sari 2005).”
Long-Term Collisional Evolution of Debris Disks (2007, methodology): “Note that what Pan & Sari (2005) call “breaking radius” is our “transition radius”st, and their “radius of equilibrium” is our “breaking radius”sb. 4.4.”