Gas and Dust Layers from Cassiopeia A’s Explosive Nucleosynthesis L. Rudnick, University of Minnesota OMEG07

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)

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?

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? Add pictures •

Outer and reverse shocks EXPLOSION STRUCTURE Outer and reverse shocks

Multiple temperature overlapping plasmas EXPLOSION STRUCTURE Multiple temperature overlapping plasmas 104K relativistic 107K 102K

EXPLOSION STRUCTURE Proper Motions optical X-ray (~radio)

A paradox – optical, X-ray, radio EXPLOSION STRUCTURE A paradox – optical, X-ray, radio

New view of the explosion EXPLOSION STRUCTURE New view of the explosion

The motion of material is different than the motion of the shock – EXPLOSION STRUCTURE 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

EXPLOSION STRUCTURE Doppler 3D structure Show movies Argon Silicon

The Explosion in 3-D

The explosion of the inner layers has a flattened (pancake) structure EXPLOSION STRUCTURE 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

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

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

Different layers in the dust

Dust – compositions Circumstellar Small carbon grains, PAH? DUST TYPE & MASS Circumstellar Small carbon grains, PAH? Deep layers Si, Ar, S + dust: SiO2, FeO, MgSiO3 Note – several different types of continuum with weak or no silicates Intermediate layers: Ne, O + dust: Al2O3

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

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

Ejecta dust mass…total visible… DUST TYPE & MASS Ejecta dust mass…total visible… 0.02 < Mdust/MO < 0.054 . CSM Silicates C-products 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! Uncertainties from thickness of H envelope, CSM, amount of destruction

Very cold ejecta dust? or ISM from foreground CO clouds? Uncertainties DUST TYPE & MASS How to fit 70m? 70m 21m Very cold ejecta dust? or ISM from foreground CO clouds? 850m 13CO 70 clearly connected with 21, therefore ejecta – but fitting quite uncertain because requires cooler components, e.g., 50??, that make only smaller contribution How much dust has not yet reached reverse shock?

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

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? Add pictures .