theorigin of$elemental$abundances$ … · sebastian elser universität zürich michael. r. meyer...
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Sebastian Elser Universität Zürich Michael. R. Meyer ETH Zürich Ben Moore Universität Zürich
The Origin of Elemental Abundances of the Terrestrial Planets
Bulk chemical composi;on • „What are rocky exoplanets made of?“
Predic;on of chemical composi;on of extrasolar planets (e.g. C-‐rich planets, Bond et al., 2010)
• „Can life form on those planets?“ Abundance of biologically important elements (H,C,N,O,P and S)
• „Do N-‐body simula;ons work properly?“ Test for dynamical simula;ons, reproducing Solar System bulk composi;ons (Bond, LaureQa and O‘Brien, 2010)
Ø Goal: study dependence on model assump;ons and planet proper;es
Introduction Methodology Results Conclusion
Introduction Methodology Results Conclusion
Methodology (Based on Bond et al., 2010)
Bond et al, 2010b
Gas in protoplanetary disk
Dust par;cles
Planetesimals
Planets
Dynamical N-‐body simula;ons (Morishima et al., 2010)
Introduction Methodology Results Conclusion
Methodology (Based on Bond et al., 2010)
Bond et al, 2010b
Gas in protoplanetary disk
Dust par;cles
Planetesimals
Planets
Disk model (T and P profile) at t=0, Equilibrium condensa;on calcula;ons
Ini;al condi;ons of dynamical N-‐body simula;ons (Morishima et al., 2010)
Dynamical N-‐body simula;ons (Morishima et al., 2010)
Introduction Methodology Results Conclusion
Methodology (Based on Bond et al., 2010)
Bond et al, 2010b
1. Source regions
Introduction Methodology Results Conclusion
Methodology (Based on Bond et al., 2010)
Bond et al, 2010b
2. Abundance profiles
1. Source regions
Introduction Methodology Results Conclusion
Methodology (Based on Bond et al., 2010)
Bond et al, 2010b
2. Abundance profiles
1. Source regions
3. Bulk chemical abundances
Introduction Methodology Results Conclusion
1. Source regions
Bond et al, 2010b
Num
ber o
f pla
nete
sim
als
Introduction Methodology Results Conclusion
Depends on location and mass of final planet.
High mass Low mass a b c d
Introduction Methodology Results Conclusion
2. Radial abundance profiles
O
Fe
Si
S
Al
„cold“ disk „warm“ disk
O Fe
Si
S Al
Introduction Methodology Results Conclusion
3.Bulk chemical composi;on
+ = ?
Introduction Methodology Results Conclusion
„warm“ disk „cold“ disk
Merkury Venus Earth Mars
vola
tility
normalized to Si:
Introduction Methodology Results Conclusion
• Source regions: massive planets and close-‐in planets have flaQer source regions than smaller planets.
• Cold disk: effects of dynamics are surpressed.
• Warm disk: limited variety in bulk composi;on of refractory and vola;le elements. Dependence on mass and semi-‐major axis of the final planet.
• Solar system bulk abundances are not reproduced in detail.
Conclusions
Disk model (2 one-‐dimensional, 1 two-‐dimensional)
Sigma(r) , T(r), P(r) at beginning of dynamical simula;ons
Ini;al condi;ons of dynamical simula;ons (2 disk masses) (Morishima et al., 2010)
wt%. of elements in solids
dynamical simula;ons (Morishima et al., 2010)
Bulk composi;on of ini;al planetesimals
Ini;al loca;on of planetsimals (Morishima et al., 2010)
Bulk composi;on of planets
Abundance profiles
Source regions
1.
2.
3.
Equilibrium condensa;on calcula;ons (14 major rock forming elements)
Bond et al, 2010b
Initial planetesimal disk
Final planets
Abundance profile
• Constraints on Solar system bulk composi;on?
• Dependence on ini;al condi;ons of dynamical simula;ons?
• Transi;on from dust to planetesimals (;me scales, loca;on) ?
• Conserva;on of bulk composi;on during mergers?
Outstanding ques;ons
Hydrogen
Only the two coldest disks provide H condensation inside 4 AU.
Extreme composi;ons
Extreme composi;ons