Solar System Shifts in Oxygen Isotopes Associated with Supernova

Injection of Aluminum 26

Carola Ellinger, Patrick Young & Steve Desch

School of Earth and Space Exploration

Arizona State University

72nd Meeting of the Meteoritical Society

July 17, 2009

OutlineGounelle & Meibom (2007) claimed that if 26Al was injected from a single supernova, the pre-injection composition = Sun composition (measured by Genesis) must have been 17O-rich.

Really?

We compute yields of oxygen isotopes and 26Al in 1D and 3D supernova explosion simulations, and the shifts in solar nebula oxygen due to injection of meteoritic abundances of 26Al.

We conclude there is a wide range of possible outcomes, many leading to large shifts, but some < 3 permil.

We provide a scenario consistent with meteoritic data.

Premature to rule out supernova injection based on oxygen isotopes.

Gounelle & Meibom (2007), Figure 1

nebula before supernova injection (inferred)

nebula after supernova

injection SMOW

If pre-injection solar nebula = Genesis has d17O > 0, it would effectively rule out injection of 26Al from single supernova.

Genesis Data 17O = -26 permil (McKeegan et al. 2009)

FUN FL

17O = -24 permil (Krot et al. 2008)

Solar Nebula Starting Composition

Starting composition probably ≈ (-60,-60). Is single supernova injection ruled out?

No! Not if post-injection composition maps onto meteoritic samples!

TFL

YR

MIF

SMOW

?

Corundum, hibonite

17O = -24 permil (Makide et al. 2009)

Solar Nebula Starting Composition

Oxygen isotopic shifts < few permil, or larger shifts along slope-1 line, allowed by data.

TFLSMOW

YR

MIF"Normal" CAIs (e.g., Itoh et al. 2004)

isotopic shift ?

Supernova NucleosynthesisTycho code (Young & Arnett 2005) used to simulate a variety of progenitors, including: 23 M (with varying delays); 16 M and 23 M with hydrogen envelope stripped in Case B binary scenario; and 40 M evolving to WC/O (see Young et al. 2009).

1D Lagrangian code (Herant et al. 1994) used to model collapse, core bounce.

For 3D simulations, output of 1D code mapped into 1 million SPH particles in SNSPH code (Fryer et al. 2006). Anisotropy introduced during this mapping by increasing velocities in cone near axis, decreasing velocities elsewhere conserving kinetic energy, mimicking observed (e.g., spectropolarimetry) supernova explosion geometries (see Fryer et al. 2006 for details).

Output post-processed using Burn code (Fryer & Young 2007) to compute nucleosynthesis.

Mapping of Cassiopeia A supernova remnant by Delaney et al. (2009), from Chandra website.

Key: Green = Fe (X ray); Yellow = Ar, Si (X ray, optical, IR); Red = cooler debris (IR); Blue = shock, (X ray).

Fe jet

Fe jet

Supernovae are clumpy, anisotropic. Injection of "Bulk" ejecta not required

Si/S outflow

26Al produced in C-burning zone in progenitor, and explosively in C/Ne-burning zones.

In 1D simulations, high densities and p,n captures make 17O, 18O from 16O but then destroy them. 17O/16O and 18O/16O low, esp. in 26Al zones.

In 3D simulations, densities fall quickly in the "jets", quenching before 17O, 18O destroyed.

18O from beta decay of 18F; at high T (>1.5 x 109 K) can decay to 14N instead of 18O, esp. in 1D explosions. 18O yields in 3D sensitive to thermodynamic history of ejecta.

Supernova Nucleosynthesis

High-velocity structures

"Bubble" regions: Hydrostatic C burning, then low densities, quenching destruction of 26Al, 17O. No explosively produced 16O. High 26Al, high 17O/16O

"Ring" regions: Explosive Ne,C burning at high densities. High 26Al and 16O. Very high 17O/16O.

High-velocity structures

"Bubble" regions: Very high 18O/16O

"Ring" regions: Very high 18O/16O

Ellinger, Young & Desch (in prep for ApJ)

Shifts in 17O moderate but variable; 18O large and variable

Ellinger, Young & Desch (in prep to ApJ)

Shifts in both isotopes variable.

Shifts in both 17O and 18O are small for 23 M progenitor, whether one takes bulk or from 26Al-rich zones.

Mass is in the sweet spot (15-25 M) where shell H burning produces lots of 26Al but does not expel it in a Wolf-Rayet wind.

1D, bulk

Solar Nebula Starting Composition

3D, bulk

3D, Ring

3D, Bubble1D, bulk

23 M progenitor cases

MIFYR

Solar Nebula Starting Composition

Even allowing 26Al to decay 1 Myr, shift from 23 M progenitor is < 10 permil, along slope-1 line.

TFLSMOW

YR

MIF"Normal" CAIs (e.g., Itoh et al. 2004)

isotopic shift ? Isheyevo CAIs

(Gounelle et al. 2009)

Acfer 214 chondrule (Kobayashi et al. 2003)

Conclusions

Oxygen isotope and 26Al yields in supernova ejecta highly variable, sensitive to not just progenitor mass but also explosion anisotropy.

Injection of meteoritic abundance of 26Al usually shifts oxygen isotopes many tens of permil, but not always*.

A viable scenario may be symmetric explosion of intermediate- mass progenitor shifting solar nebula down slope-1 line < 10 permil. Later MIF moves nebula up slope-1 line.

Premature to use oxygen isotopes to rule out injection of 26Al from a single supernova.

* Chemical fractionation during injection into disk (Ouellette et al. 2007)---Al gets in via corundum grains but O remains in gas phase and is not injection---can reduce shifts to << 1 permil.

Key: Green = Fe (X ray); Yellow = Ar, Si (X ray, optical, IR); Red = cooler debris (IR); Blue = shock, (X ray).