1. THEORETICAL ASTROPHYSICS AND THE US-NVO INITIATIVE D. S. De Young National Optical Astronomy Observatory

2. Theory Then Exact Solutions (rare) Analytic Approximations (enable rapid progress in new areas – but…) Limited Numerical Simulations (sometimes misleading) E/O Relevance – None (Maclaurin spheroids??)

3. Comparison with Observations – Very Difficult Idealized geometries, initial and boundary conditions Many important processes omitted No radiative signatures produced Theory Then

4. Theory Now Exact Solutions (rare) Analytic Approximations (still useful) Large Scale, Sophisticated Numerical Simulations – Three dimensional, high resolution – Gravitation, radiation processes – Special and general relativity

5. Theory Now E/O Connection – Highly Relevant – Dramatic visualizations – Graphics, animations reveal physical processes Comparison with Observations – Realistic geometries, initial conditions – Inclusion of relevant physics – Calculation of observed signatures

6. Wave of the Future: The Confrontation of Theory and Observations Truly Significant Test of Models Guide New Observations New Paradigm for Scientific Inquiry – Data mining in a truly virtual sky Enabled by the Virtual Observatory

7. Three Dimensional MHD Jet Propagation I. The Calculations (Tregillis, Jones, & Ryu 2001) – Includes Radiation losses, power law initial spectrum Particle reacceleration at shocks

8. 3-D Jet Propagation II. The Radiative Signatures 5.4 GHz synchrotron IC-CMB SSC

9. 3-D Jet Propagation III. The Observations VLA 1.5 sec 5.4 GHz Synch 1.2 KeV Chandra IC-CMB

10. The Evolution of Globular Clusters I. The Calculation (McMillan & Portegies Zwart 2002) – Orbit calculations for cluster of 65000 stars – Scalo mass function: 0.3 – 100 solar masses – Collisions, coalescence, binaries, stellar evolution

11. The Evolution of Globular Clusters The Formation and Growth of Black Holes

12. Mining Globular Cluster Simulation Datasets Observational Parameters Available – Collision vs. coalescence – Formation of binary systems – Evolution of stellar populations – Role of dark matter – Evolution of cluster morphology – Contributions to galactic metallicities

13. The Evolution of Barred Spiral Galaxies P. Teuben, J. Barnes (2002)

14. Barred Spirals: Theory and Observation Evolution of Barred Spirals (Piner, Stone & Teuben) CO Data Theory v CO + Simulation

15. The Role of Datasets from Theoretical Astrophysics Direct Comparisons with Observations – Verification (or not) of Models Data Mining for Both Observations and Theory – New Applications – Buried Physics Resource for Education and Outreach

16. Theory and the Virtual Observatory Size of Datasets Appropriate to VO – Large Scale Simulations, Parameter Space Libraries Imply 10GB – 10 TB Datasets Rich Complement to Observational Side Same/Similar Tools as for Obs. Datasets Use of VO Infrastructure – Grid Technology, Portals, etc.

17. Theory and the US-NVO Early discussions among subset of US theorists Formation of an interim “TVO” site Inclusion of theory group on NVO SWG Representation on US-NVO Exec

18. The US TVO Site

19. Sample NVO-TVO Capability Galaxy Cluster Evolution – Correlations of x-ray and optical properties – Access all available catalog data Correlate optical and x-ray morphologies, fluxes Correlate with associated radio emission Bin by redshift Form new catalogs – Access libraries of numerical simulations – Find correlations

20. Conclusions Theoretical Astrophysics an Essential Part of the Virtual Observatory Concept – Provides Benefits to Theorists – Provides Benefits to Observers – Provides Benefits to Education/Outreach Drives New Science