Supernova Galaxy Environment SD

Introduction

An astronomer wants to ascertain whether a supernova candidate is Type Ia or Type II. Determining galaxy redshift and morphology of the environment in which the supernova candidate was discovered will aid classification.

Flow of Events

First, the astronomer searches the resource catalogue for optical or IR image data catalogues covering known supernova positions. The astronomer selects a catalogue from the returned list and requests images from the catalogue, based on position. The astronomer then acquires recent observations of the same location (in the same wavelength) from a telescope resource. The new observation image is uploaded onto Astrogrid; it is subtracted from the old image, creating a new subtracted image. The astronomer then uploads an algorithm to check the new image for objects that have moved between the first and second observation; these objects are eliminated as near Earth objects. Finally, a catalogue is generated of the remaining supernova candidates.

Sequence Diagram

The flow of event is more like as follows. The above describes how one would support the actual discovery of the SN via facilitating the running of search alogorithms (image subtraction etc).

For SN search areas:

1. search literature and published sources for possible spectroscopic redshifts of galaxies in fields.
2. search archives for spectroscopic data of objects in field > determine redshifts of galaxies in fields using perhaps automated techniques such as devloped for the 2dFGRS (see Colless et al, 2001)
3. Locate multicolour broadband optical data for the search fields
4. Determine photometric redshifts to galaxies in the fields using a variety of techniques (e.g. hyperz, more recently (2002) Z-Peg).
5. identify possible galaxy clusters (see e.g. OpticalNearIRGalaxyClusterSelection)
6. cross reference position of newly discovered SN from search. If located in a galaxy for which the redshift is known from one of the above techniques, return an assigned redshift for that SN (together with estimation of error).
7. return morphological information of the galaxy in which the SN candidate is located (if applicable)

-- NicholasWalton - 31 May 2002

UseCases:

These use cases are the ones that will be needed to deliver this case.

1. AuthenticateIdentity
2. PerformLiteratureSearch
3. PerformRegistrySearch
4. NegotiateAccessToResource
   • AuthenticateIdentity
   • DetermineAuthority
5. PerformCatalogueSearch
6. MySpaceStoreResults
   • NegotiateAccessToResource
     • AuthenticateIdentity
     • DetermineAuthority
7. DetermineProgram
   • AccessLibraryFunction
     • NegotiateAccessToResource
       • AuthenticateIdentity
       • DetermineAuthority
   • AccessWebService
     • NegotiateAccessToResource
       • AuthenticateIdentity
       • DetermineAuthority
   • UploadUserCode
     • NegotiateAccessToResource
       • AuthenticateIdentity
       • DetermineAuthority
     • MySpaceStoreResults
       • NegotiateAccessToResource
         • AuthenticateIdentity
         • DetermineAuthority
   • NegotiateAccessToJob
8. MySpacePublishDerivedData
9. SelectCatalogue

-- ElizabethAuden - 30 May 2002