Use Case: Multiwavelength analysis of interstellar clouds

Description

An observer gets reduced spectra at different wavelengths towards a molecular cloud and tries to match these spectra by a physico-chemistry model and a radiative transfer model to get physical conditions in the cloud. He searches the registries to find relevant codes (in this case a PDR code and a radiative transfer code). He sends parameters to the PDR code which computes temperature and abundances at each point of the cloud. These results are send to the radiative transfer code which produces the synthetic spectrum to be compared to the observations. Such codes use a lot of atomic and molecular physical data so the codes are linked to databases providing such quantities to stay up to date.

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Primary actor

Astronomer

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End Result

Spectra are obtained from numerical physico-chemistry and radiative models

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Secondary actor

Simulator

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Other actors

Simulators Atomic and molecular databases in the VO

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Pre Condition

Get spectra in VO format

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Inter Condition

Results from PDR code are transmitted in VO-Table format to be understood by radiative transfer code

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Post Condition

Results from radiative transfer code are transmitted in a VO-Spec format to be compared to real spectra in a VO-tool

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Flow of events

1. User browses registries to find a physico-chemistry model codes (PDR code)
2. User selects service and gives entrance/exit parameters to the PDR code
3. Service "PDR code" compute a solution and send abundances and temperature in a VO-Table format to the user
4. User browses registries to find a radiative transfer code
5. User selects an appropriate radiative transfer code and send the VO-Table to the radiative transfer code. Depending on the radiative transfer code he may have to give other parameters
6. Service "radiative transfer code" compute spectrum and send it to Observer in a VO-Spec format
7. User compares his spectra and synthetic spectra thanks to a VO-tool.

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Independent flow of events

1. Periodicaly PDR and radiative transfer codes send a request towards atomic and molecular databases to check for more recent data
2. Databases transmit informations to codes in VO-Table format

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-- FranckLePetit - 28 Sep 2005