Post on 05-Jan-2016
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