Debris disk size distributions: steady state collisional evolution with Poynting-Robertson drag and other loss processes

Download
  1. Get@NRC: Debris disk size distributions: steady state collisional evolution with Poynting-Robertson drag and other loss processes (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1007/s10569-011-9345-3
AuthorSearch for: ; Search for: ; Search for:
TypeArticle
Journal titleCelestial Mechanics and Dynamical Astronomy
ISSN0923-2958
Volume111
Issue1-2
Pages128; # of pages: 28
SubjectCircumstellar matter; Planetary systems; Debris disks; Collisional cascade; Mass loss rate; Size distribution modeling
AbstractWe present a new scheme for determining the shape of the size distribution, and its evolution, for collisional cascades of planetesimals undergoing destructive collisions and loss processes like Poynting-Robertson drag. The scheme treats the steady state portion of the cascade by equating mass loss and gain in each size bin; the smallest particles are expected to reach steady state on their collision timescale, while larger particles retain their primordial distribution. For collision-dominated disks, steady state means that mass loss rates in logarithmic size bins are independent of size. This prescription reproduces the expected two phase size distribution, with ripples above the blow-out size, and above the transition to gravity-dominated planetesimal strength. The scheme also reproduces the expected evolution of disk mass, and of dust mass, but is computationally much faster than evolving distributions forward in time. For low-mass disks, P-R drag causes a turnover at small sizes to a size distribution that is set by the redistribution function (the mass distribution of fragments produced in collisions). Thus information about the redistribution function may be recovered by measuring the size distribution of particles undergoing loss by P-R drag, such as that traced by particles accreted onto Earth. Although cross-sectional area drops with age α t-² in the PR-dominated regime, dust mass falls α t [exponential]-2.8, underlining the importance of understanding which particle sizes contribute to an observation when considering how disk detectability evolves. Other loss processes are readily incorporated; we also discuss generalised power law loss rates, dynamical depletion, realistic radiation forces and stellar wind drag. © 2011 Springer Science+Business Media B.V.
Publication date
LanguageEnglish
AffiliationNational Research Council Canada (NRC-CNRC); NRC Herzberg Institute of Astrophysics
Peer reviewedYes
NPARC number21271933
Export citationExport as RIS
Report a correctionReport a correction
Record identifier657fd544-226a-43e0-86a8-887f96720381
Record created2014-05-07
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)