How Extrasolar Planetesimals Show Up in Spitzer Data
First Author:
Torsten Löhne
Email: tloehne AT astro.uni-jena.de
Astrophysical Institute Jena
Schillergaesschen 2-3
07745 Jena, Germany
Coauthors:
Krivov, Alexander, Astrophysical Institute Jena
Müller, Sebastian, Astrophysical Institute Jena
Mutschke, Harald, Astrophysical Institute Jena
Rodmann, Jens, ESA/ESTEC, Noordwijk
Abstract
One of the major goals to study debris disks is to constrain various properties of their main mass reservoir, the planetesimal populations. However, models are needed in order to link these invisible planetesimals to the observable dust they are thought to produce. We employ our collisional code, ACE, interpret results by means of an analytic model and compare them to available observational data for G-type stars, including Spitzer/MIPS results from various datasets. The aim is to find out, which planetesimal properties can be constrained (i) from the statistics of fractional luminosity decay with age and (ii) from the observed SED of one or another particular disk. Regarding the first question, our results suggest that the observed decay in the dust luminosity is directly linked, among other parameters, to the primordial size distribution of planetesimals set at their accretion epoch. For individual disks, we show how SEDs may help not only to constrain the locations but also the masses of parent planetesimal belts; we find the observed excesses to be compatible with dust steadily produced in massive and large Kuiper belt analogs.
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