from stars to planets gainesville 14 april 2007 short-lived radioisotopes: a cosmochemical...
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From Stars to Planets Gainesville 14 April 2007 Markowski et al. (2006) Early (TRANSCRIPT
From Stars to Planets Gainesville 14 April 2007
Short-lived radioisotopes:A cosmochemical connection
between star and planet formation
Eric Gaidos1,3 Jonathan Williams2,3
Nick Moskovitz2
Daniel Rogerrs4
1Department of Geology & Geophysics2Institute for Astronomy3NASA Astrobiology Institute4Department of Physics & AstronomyUniversity of Hawaii at Manoa
Launch of COROT
From Stars to Planets Gainesville 14 April 2007
Armstrong et al. (1984)
Evidence for live 26Al in the early Solar System
From Stars to Planets Gainesville 14 April 2007 Markowski et al. (2006)
Early (<2 Myr) differentiation of some meteorite parent bodies
From Stars to Planets Gainesville 14 April 2007
Evidence for the homogeneity of 26Al
Thrane et al. (2006)
From Stars to Planets Gainesville 14 April 2007
Bizzarro et al. (2006)
Absence of 60Fe in iron meteorite parent bodies?
From Stars to Planets Gainesville 14 April 2007
Contribution to 26Al by Wolf-Rayet winds
From Stars to Planets Gainesville 14 April 2007
Meynet & Maeder (2005)
26Al
60Fe
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Overlapping time scales
Half life of 26Al 0.72 Myr
Massive star lifetime >3 Myr
Protostar and disk lifetime 1-5 Myr
Cluster dispersal time 1-10 Myr
Accretion time scale 1-10 Myr
From Stars to Planets Gainesville 14 April 2007
N-body simulations of a 9000-star cluster containing a 60 solar-mass (O3) star
and ~270 solar mass (0.9-1.1) stars
t = 0 t = 3 Myr
From Stars to Planets Gainesville 14 April 2007
Williams & Gaidos, in prep.
N = 9000
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From Stars to Planets Gainesville 14 April 2007
Cumulative distribution of relative 26Al inventories
0.1X 10X1X
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Thermal histories of 3-km planetesimals with Solar, 0.1X, and 10X 26Al
From Stars to Planets Gainesville 14 April 2007
Fractional Mass Experiencing Temperatures < 700K
0
0.2
0.4
0.6
0.8
1
0 2 4 6 8 10 12 14 16 18 20
Accretion Timescale [Myr]
1X0.1X10X
From Stars to Planets Gainesville 14 April 2007
Leger et al. (2004)
Less dehydration: Ocean worlds?
From Stars to Planets Gainesville 14 April 2007
Disk injection scenario
• Single O3 (60 solar-mass star) in 500 star cluster
• Plummer sphere with specified core radius and virial parameter ≥0.5 reflecting gas loss (Bastian & Goodwin 2006)
• Simulation stopped at 3.8 Myr • Yield of 26Al in wind from Limongi &
Chieffi (2006)• Injection efficiency of 100%; no decay
during time of flight• Mass fraction of 26Al calculated according
to Looney et al. (2006):
time of flight of ejecta
ss
ti
i DeMfX
2
/2ln
4
2/1
injection efficiency
mass of isotope in ejecta
distance from SS to progenitor
surface density of SS
solar system value; 26Al/27Al = 5.85 × 10-5
From Stars to Planets Gainesville 14 April 2007
g = 0.5
g = 0.9
From Stars to Planets Gainesville 14 April 2007
Denizens of a low 26Al world....