Back to IVOA Theory: Science Use Cases

Use case: Comparison/use of evolutionary synthesis models

Description

Case A: A user with deep knowledge of evolutionary synthesis models wants to compare the results given by different grids of models (produced by different developers/groups) for the same set of input parameters.

Case B: A user wants to retrieve an specific evolutionary synthesis model to perform a simple comparison (overplot) with real data.

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primary actor

Case A: Evolutionary synthesis model expert user

Case B: Evolutionary synthesis model standard user

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End result:

Case A: Plot by VOSpec of results obtained from different grids of models with the same input parameters (age and metallicity).

Case B: Plot by VOSpec of results of theoretical and real data.

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Other actors:

Case A: Evolutionary synthesis model server

Case B: Evolutionary synthesis model server, observational data server

- VOSpec

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Pre-conditions

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

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Flow of events

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

Case A:

1. User logins in VOSpec and selects the corresponding service.
2. In response to the "format=metadata" query, the service sends a VOTable to VOSpec with the parameter space (and the associated valid values) that defines the grid of models.
3. The user selects the desired parameters/values, and VOSpec send them back to the service.
4. 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.

Case B (includes Case A, plus):

1. The user chooses an spectroscopic observation with VOSpec.
2. Models and observations are plotted and normalized to a common scale.

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Post-condition

1. Results provided in VOTable format

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Basic assumptions

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

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Alternative flows

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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...?

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Originally sent by M. Cerviño - 27 Sep 2005
Last modified: E. Solano - 28 Sep 2005

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