Chondrule Formation - Jeremiah Horrocks · Stammler & Dullemond (2014) Impossible to melt the...
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Chondrule Formation Shock Model vs. Impact Model Chondrule Formation Shock Model vs. Impact Model Sebastian Markus Stammler 1 Cornelis Petrus Dullemond 1 , Daniel Harsono 1 , Anders Johansen 2 1 Center for Astronomy, Institute of Theoretical Astrophysics, Heidelberg University 2 Lund Observatory, Sweden Disc Dynamics & Planet Formation Cyprus, 29 June – 3 July
Transcript of Chondrule Formation - Jeremiah Horrocks · Stammler & Dullemond (2014) Impossible to melt the...
Chondrule FormationShock Model vs. Impact ModelChondrule Formation
Shock Model vs. Impact Model
Sebastian Markus Stammler1
Cornelis Petrus Dullemond1, Daniel Harsono1, Anders Johansen2
1 Center for Astronomy, Institute of Theoretical Astrophysics, Heidelberg University2 Lund Observatory, Sweden
Disc Dynamics & Planet Formation Cyprus, 29 June – 3 July
Credit: E. Moser
Credit: E. Moser
Credit: Jürgen Otto & Norbert Classen
1 mm
Constraints on chondrule formation:
● Flash heating
● Cooling rates
● Chondrule size distribution
● Chondrule-matrix complementary
● Chondrule age
● ...
Constraints on chondrule formation:
● Flash heating
● Cooling rates
Energy argument
Required energy:
35 300 J/g (Wasson 1996)
Estimated chondrule mass:
~1027 g (Morris & Desch 2009)
Total energy needed:
3.5 x 1031 J = 9.8 x 1024 kWh
in 2011: 4.77 x 109 kWh
2.1 x 106 Gyr
data.worldbank.org
Cooling rates
Desch et al. (2012)
The shock model
Boley & Durisen (2008)
The shock model
● 1-D, stationary hydro model
● Decelleration by drag force
● Frictional heating
● With radiative transfer
The shock model
Stammler & Dullemond (2014)
Tpeak
Tpost
The shock model
Stammler & Dullemond (2014)
Impossible to melt the chondrule completely AND sustain a lowpost-shock temperature simultaneously
solidus
liquidus
The shock model
Estimation of energy loss by radiative diffusion
0.01 HP
0.02 HP
0.04 HP
∞
Diffusive length scale
Even with unrealistically short diffusion length scalesThe particles stay hot for too long.
Credit: NASA/JPL-Caltech
The impact model
The impact model
Dullemond, Stammler & Johansen (2014)
Three main parameters: M cloud , T 0 , v exp
Optical depth from center to surface: τ ( t)=3
4 π
M cloud κ
vexp2
1t 2
Opacity: κ =34
1ξ chon achon
The impact model
Dullemond, Stammler & Johansen (2014)
In the center of the cloud:
T (t< t cool) = T 0
T (t> t cool) = T 0[ 35
tt cool
+25 ]
−5/3
t cool ∝ M cloud2 /5 T 0
−3/5 v exp−4 /5
The impact model
Dullemond, Stammler & Johansen (2014)
The impact model – the future
SPH simulation by Daniel Harsono
Summary
The shock model
The impact model
● Difficult to cool the particles in a large scale shock
● Cooling rates do not match laboratory experiments
● Possible volatile loss
● Even in a simple approach the cooling rates can match the requirements for a wide parameter range
● Volatile loss can be prevented by saturation in high density regions
● SPH simulations are performed for more detailed calculations
