Use Case: Multiwavelength analysis of interstellar clouds


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.

Primary actor


End Result

Spectra are obtained from numerical physico-chemistry and radiative models

Secondary actor


Other actors

Simulators Atomic and molecular databases in the VO

Pre Condition

Get spectra in VO format

Inter Condition

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

Post Condition

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

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.

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

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.

-- FranckLePetit - 28 Sep 2005

Topic revision: r2 - 2005-09-28 - FranckLePetit
This site is powered by the TWiki collaboration platformCopyright © 2008-2019 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback