Gas and Dust Layers from Cassiopeia A’s Explosive Nucleosynthesis

1. Gas and Dust Layers fromCassiopeia A’sExplosive Nucleosynthesis L. Rudnick, University of Minnesota OMEG07

2. The work of many experts… SPITZER T. DeLaney, MIT J. Ennis, U Mn T. Kozasa, Hokkaido H. Morgan, Cardiff W. Reach, Spitzer J. Rho, Spitzer J.D. Smith, U. Ohio RADIO, X-RAY, OPTICAL R. Petre, U. Hwang, GSFC R. Fesen (Dartmouth) J. Bowden (Colorado Coll.) N. Kassim (Naval RL) Funding: NASA (Chandra/HST/Spitzer) and NSF (radio)

3. Key Questions • What is the shape of the explosion? • What is the fate of the nucleosynthesis layers? • What is the mass and composition of new dust? • What is the future?

4. • Messages to take home • Until now, the ONLY ejecta which have been seen in Cas A (optical, IR, X-ray, radio) are those that have just crossed the reverse shock • The explosion of the inner layers was flattened. with multiple “jets”  different nucleosynthesis layers are now visible in each direction. • Dust becomes visible at the reverse shock, with different compositions from different layers • The currently visible dust mass is 0.02-0.05 MO, with even more in the interior? •

5. EXPLOSIONSTRUCTURE Outer and reverse shocks

6. EXPLOSIONSTRUCTURE Multiple temperature overlapping plasmas 104K relativistic 107K 102K

7. EXPLOSIONSTRUCTURE Proper Motions optical X-ray (~radio)

8. EXPLOSIONSTRUCTURE A paradox – optical, X-ray, radio

9. EXPLOSIONSTRUCTURE New view of the explosion

10. EXPLOSIONSTRUCTURE • The motion of material is different than the motion of the shock – • Ejecta become visible as they encounter the reverse shock Milliseconds seconds into the explosion

11. EXPLOSIONSTRUCTURE Doppler 3D structure Argon Silicon

12. The Explosion in 3-D

13. EXPLOSIONSTRUCTURE • The explosion of the outer layers was spherical, setting up forward and reverse shocks. • The explosion of the inner layers has a flattened (pancake) structure • “Fingers” or jets of material protrude in the plane separating the layers

14. NUCLEOSYNTHESIS LAYERS As the jets cross the reverse shock and become visible, the nucleosynthesis layers remain intact

15. NUCLEOSYNTHESIS LAYERS Different layers in the gas Ne-rich layers OIV X-ray Si GAP

16. Different layers in the dust

17. DUST TYPE & MASS Dust – compositions Circumstellar Small carbon grains, PAH? Deep layers Si, Ar, S + dust: SiO2, FeO, MgSiO3 Intermediate layers: Ne, O + dust: Al2O3

18. DUST TYPE & MASS Dust Composition - closer look Deep, O-burning Intermed., C-burning Al2O3 proto-silicate peak

19. DUST TYPE & MASS Dust Mass Distributions Deep, O-burning Intermed., C-burning

20. . 0.02 < Mdust/MO < 0.054 CSM Silicates C-products DUST TYPE & MASS Ejecta dust mass…total visible… Expectations for production, e.g., Nozawa et al. 2003 up to ~1 MO Low end of requirement for dust seen at high z, BUT, destruction should also be very important!

21. Uncertainties DUST TYPE & MASS Very cold ejecta dust? or ISM from foreground CO clouds? How to fit 70m? 21m 70m 13CO 850m How much dust has not yet reached reverse shock?

22. FUTURE Is there more dust to come? Si XIV Si II

23. Messages to take home • Until now, the ONLY ejecta which have been seen in Cas A (optical, IR, X-ray, radio) are those that have just crossed the reverse shock • The explosion of the inner layers was flattened. with multiple “jets”  different nucleosynthesis layers are now visible in each direction. • Dust becomes visible at the reverse shock, with different compositions from different layers • The currently visible dust mass is 0.02-0.05 MO, how much more in the interior? .