Collisional and Thermal Emission Models of Debris Disks: Towards Planetesimal Population Properties

Abstract

Debris disks around main-sequence stars are believed to derive from planetesimal populations that have accreted at early epochs and survived possible planet formation processes. While debris disks must contain solids in a broad range of sizes - from big planetesimals down to tiny dust grains - debris disk observations are only sensitive to the dust end of the size distribution. Collisional models of debris disks are needed to "climb up" the ladder of the collisional cascade, from dust towards parent bodies, representing the main mass reservoir of the disks. We have used our collisional code to generate five disks around a sun-like star, assuming planetesimal belts at 3, 10, 30, 100, and 200 AU with 10 times the Edgeworth-Kuiper-belt mass density, and to evolve them for 10 Gyr. Along with an appropriate scaling rule, this effectively yields a three-parametric set of reference disks (initial mass, location of planetesimal belt, age). For all the disks, we have generated spectral energy distributions (SEDs), assuming homogeneous spherical astrosilicate dust grains. A comparison between generated and actually observed SEDs yields estimates of planetesimal properties (location, total mass etc.). As a test and a first application of this approach, we have selected five disks around sun-like stars with well-known SEDs. In four cases, we have reproduced the data with a linear combination of two disks from the grid (an "asteroid belt" at 3 AU and an outer "Kuiper belt"); in one case a single, outer component was sufficient. The outer components are compatible with "large Kuiper belts" of 0.2-50 earth masses (in the bodies up to 100 km in size) with radii of 100-200 AU.

16 pages, 12 figures, 5 tables, accepted for publication in The Astrophysical Journal

References in corpus (10)

• Debris Disk Evolution Around A Stars
• Transience of hot dust around sun-like stars
• Debris disks around Sun-like stars
• The Complete Census of 70-um-Bright Debris Disks within the FEPS (Formation and Evolution of Planetary Systems) Spitzer Legacy Survey of Sun-like Stars
• Nearby debris disk systems with high fractional luminosity reconsidered
• Long-Term Collisional Evolution of Debris Disks
• Collisional processes and size distribution in spatially extended debris discs
• Spitzer 24 Micron Observations of Open Cluster IC 2391 and Debris Disk Evolution of FGK Stars
• Collisional dust avalanches in debris discs
• IRS Spectra of Solar-Type Stars: \break A Search for Asteroid Belt Analogs

Cited by in corpus (11)

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• The Mass Budget of Planet Forming Discs: Isolating the Epoch of Planetesimal Formation
• GJ 832c: A super-earth in the habitable zone
• Five Debris Disks Newly Revealed in Scattered Light from the HST NICMOS Archive
• Debris Disc Constraints on Planetesimal Formation
• Porous dust grains in debris disks
• Formation of Super-Earth Mass Planets at 125-250 AU from a Solar-type Star
• Fomalhaut b as a Cloud of Dust: Testing Aspects of Planet Formation Theory
• A dearth of small particles in debris disks: An energy-constrained smallest fragment size
• Dust Spreading in Debris Discs: Do Small Grains Cling on to Their Birth Environment?
• 94 Ceti: a triple star with a planet and dust disc