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SVO - ESAVO Use case: Comparison of evolutionary synthesis models


A user wants to compare the results given by different grids of evolutionary synthesis models (produced by different developers/groups) with observational data.

primary actor

Evolutionary synthesis model user.

End result:

Plot by VOSpec of results of theoretical and real data.

Other actors:

- Evolutionary synthesis model server

- VO Registry

- VOSpec


1 Existence of a protocol (e.g. TSAP) that explores (using the "format=metadata" option) the parameter space of the theoretical grid of models (not known a priori).

Flow of events

All the information exchange between the synthesis model server and VOSpec is done using the TSAP protocol.

  1. User logins in VOSpec and makes a query by object
  2. Among the SSA and theoretical services provided by VOSpec the user selects those of interest.
  3. In response to the "format=metadata" query, the selected theoretical services send a VOTable to VOSpec with the parameter space (and the associated valid values) that defines the grid of models.This information is displayed by VOSpec
  4. The user selects the desired parameters/range of values, and VOSpec send them back to the theoretical service.
  5. The service returns a VOTable with the results to be displayed by VOSpec. Depending on the server, the results can be obtained from a pre-computed grid of models or on-the-fly.
  6. Models and observations are displayed. Using VOSpec both datasets can be normalized to a common scale.


  1. Results provided in VOTable format.

Basic assumptions

Synthesis models mix the results of two types of theoretical results: evolutionary tracks and atmosphere models.

Alternative flows

Open Issues

  1. How to evaluate if the resulting model (final product of a mathematical algorithm) has a physical meaning? Use of cautions, warnings etc...?

Originally sent by M. Cerviņo - 27 Sep 2005
Last modified: E. Solano - 30 Sep 2005
Please add comments below. This area should be used for refinement of the above document. If you want to ask questions or start a dialogue with the author, please use the theory mailing list.

"The service returns a VOTable with the results..." Consider returning this table to a VOStore. This lets the derivation of the table run asynchronously from VOSpec, which may be useful if the model has to be recomputed to produce the result. Note that VOspec and similar applications can get to the storage via the AstroGrid Client Runtime.

-- GuyRixon - 04 Oct 2005

Topic revision: r9 - 2006-05-24 - BrunoRino
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