THEORETICAL ASTROPHYSICSTHEORETICAL ASTROPHYSICS ANDAND

THE US-NVO INITIATIVETHE US-NVO INITIATIVE

D. S. De YoungNational Optical Astronomy Observatory

Theory ThenTheory Then

Exact Solutions (rare)Analytic Approximations (enable rapid

progress in new areas – but…)Limited Numerical Simulations (sometimes

misleading)

E/O Relevance – None (Maclaurin spheroids??)

Comparison with Observations– Very Difficult

Idealized geometries, initial and boundary conditions

Many important processes omitted

No radiative signatures produced

Theory ThenTheory Then

Theory NowTheory Now

Exact Solutions (rare)

Analytic Approximations (still useful)

Large Scale, Sophisticated Numerical Simulations

– Three dimensional, high resolution– Gravitation, radiation processes– Special and general relativity

Theory NowTheory 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

Wave of the Future: Wave of the Future: The Confrontation of Theory The Confrontation of Theory

and Observations 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

Three Dimensional MHD Jet Three Dimensional MHD Jet PropagationPropagation

I. The Calculations (Tregillis, Jones, & Ryu 2001)

– Includes Radiation losses, power law initial spectrum Particle reacceleration at shocks

3-D Jet Propagation3-D Jet Propagation

II. The Radiative Signatures

5.4 GHz synchrotron

IC-CMB

SSC

3-D Jet Propagation3-D Jet Propagation

III. The Observations

VLA 1.5 sec

5.4 GHz Synch

1.2 KeV Chandra

IC-CMB

The Evolution of The Evolution of Globular ClustersGlobular 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

The Evolution ofThe Evolution ofGlobular ClustersGlobular Clusters

The Formation and Growth of Black Holes

Mining Mining Globular Cluster SimulationGlobular Cluster Simulation

DatasetsDatasetsObservational 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

The Evolution of BarredThe Evolution of BarredSpiral GalaxiesSpiral Galaxies

P. Teuben, J. Barnes (2002)

Barred Spirals: Barred Spirals: Theory and ObservationTheory and Observation

Evolution of Barred Spirals (Piner, Stone & Teuben)

CO Data

Theory

v

CO + Simulation

The Role of Datasets fromThe Role of Datasets fromTheoretical AstrophysicsTheoretical 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

Theory and the VirtualTheory and the VirtualObservatoryObservatory

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.

Theory and the US-NVOTheory 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

The US TVO SiteThe US TVO Site

Sample NVO-TVO CapabilitySample 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

ConclusionsConclusions

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