Solar System Shifts in Oxygen Isotopes Associated with Supernova Injection of Aluminum 26

1. 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

2. Outline Gounelle & 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.

3. nebula before supernova injection (inferred) nebula after supernova injection  SMOW Gounelle & Meibom (2007), Figure 1 If pre-injection solar nebula = Genesis has d17O > 0, it would effectively rule out injection of 26Al from single supernova.

4. Starting composition probably ≈ (-60,-60). Is single supernova injection ruled out? No! Not if post-injection composition maps onto meteoritic samples! SMOW TFL MIF YR Genesis Data 17O = -26 permil (McKeegan et al. 2009) FUN FL 17O = -24 permil (Krot et al. 2008) Corundum, hibonite 17O = -24 permil (Makide et al. 2009) Solar Nebula Starting Composition ?

5. Oxygen isotopic shifts < few permil, or larger shifts along slope-1 line, allowed by data. SMOW TFL MIF "Normal" CAIs (e.g., Itoh et al. 2004) YR isotopic shift ? Solar Nebula Starting Composition

6. Supernova Nucleosynthesis Tycho 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.

7. Fe jet Si/S outflow Fe jet Supernovae are clumpy, anisotropic. Injection of "Bulk" ejecta not required 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).

8. Supernova Nucleosynthesis 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.

9. "Bubble" regions: Hydrostatic C burning, then low densities, quenching destruction of 26Al, 17O. No explosively produced 16O. High 26Al, high 17O/16O High-velocity structures "Ring" regions: Explosive Ne,C burning at high densities. High 26Al and 16O. Very high 17O/16O.

10. "Bubble" regions: Very high 18O/16O High-velocity structures "Ring" regions: Very high 18O/16O

11. Ellinger, Young & Desch (in prep for ApJ) Shifts in 17O moderate but variable; 18O large and variable

12. 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. Ellinger, Young & Desch (in prep to ApJ)

13. 23 M progenitor cases 3D, Ring MIF YR 3D, bulk 1D, bulk 1D, bulk 3D, Bubble Solar Nebula Starting Composition

14. Even allowing 26Al to decay 1 Myr, shift from 23 M progenitor is < 10 permil, along slope-1 line. SMOW TFL MIF "Normal" CAIs (e.g., Itoh et al. 2004) YR isotopic shift ? Isheyevo CAIs (Gounelle et al. 2009) Acfer 214 chondrule (Kobayashi et al. 2003) Solar Nebula Starting Composition

15. 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.

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