High redshift case

Tools call 2007 PareshPrema

Progress notes 27 September 2007 Updated

Discussion between PareshPrema PP, AnitaRichards, AMSR, MarkTaylor MT, GuyRixon GTR

5 Feb 2008 update

  1. SExtractor - AG tool OK in principle but not working
    • PP/AMSR to nag PAH
    • See http://www.astrogrid.org/bugzilla/show_bug.cgi?id=2553
      • This covers adding a few more parameters to the UI
    • Data sets I wish to use are here: http://www.ast.cam.ac.uk/~pprema/subaru/
      • I would like to use OPTiCAL (Subaru - bviz and a U band image if found), UKIDSS-UDS(JK) and SWIRE(3.6-8.0micron)
    • How to make sure OPTiCAL (subaru) and UKIDSS measurements are compatible?
      • Suggestion - use UKIDSS aperture for all, but censor objects in both data sets which are extended or confused in OPTICAL.
    • Need better, easier access to images and their metadata via AstroGrid. Image access has already been identified as a future issue. We need to look at how we could use the Char model etc. to serve metadata although this would in some cases require work by the providers where vital information is squirrelled away in papers etc.
  2. Cross-match - Impliment AstroGrid tool to crossmatch a flexible and large number of catalogues (i.e. take tmatch2 tool from current stilts app and enhance)
    • MT with input from AMSR
    • Simple tool for crossmatching two catalogues now available as a CEA application which can be used in TaskRunner or scripting. tmatchn now avaliable in stand-alone STILTS, so the same Python script could drive a local STILTS and use CEA for other things, although it might be desirable eventually to have tmatchn accessible via CEA.
      • CEA deployment of tmatchn is not currently under way. Though this would probably be possible, it would require a significant amount of effort because of CEA/STILS parameter system mismatches -- Mark
      • Paul Harrison adds I have just about finished (as of 16 May 2008) work on the CEA server side that introduces the newer parameter model that is represented in http://www.jb.man.ac.uk/~pah/ivoa/CEAApplicationDM.html, which allows more complex relationships between the parameters to be expressed (e.g. grouping, requirement conditional on value of other parameter...). The next stage is to update the VODesktop to make the taskrunner understand and represent these relationships, and then finally the application definitions themselves need to be updated to take advantage of the new model. I think that this will then allow us to address many of the problems that people experience with running other applications like galaxev, as there are complex relationships between parameters which mean that with the current model it is too easy to supply incorrect values for a parameter - that said I tmatchn might still be a challenge to fit into the generalized task runner.
      • but can we suppress that and just make it available for scripting? Anita
  3. HyperZ OK technically but need to be able to tune/assess output
    • PP with (probably not much useful) input from AMSR - Ask RMcM?
  4. Comparison with models
    • Starburst99 - OK? - No it either seems to hang or comes back with an error
      • Parameter ILIB (metallicity of high res models) is missing so "hres" output can't be produced
      • The UI gives a default value of 3 for the box headed SMALL (=0) OR LARGE (=1) MASS GRID; ISOCHRONE ON LARGE GRID (=2) OR FULL ISOCHRONE (=3):, which is incompatible with the "hrd" output. The default should be 1 and the box should have a shorter name!
    • Pegase - fix error in viewing info field and see if output format can be converted to VOTable inside tool and HTTP 502 error when run GTR this is the version called Pegase 2 which gives a CEA error right at the start if run with the defaults
      • There is also a version at Jodrell (just called Pegase) which does try and run with the defaults but eventually gives a what looks like a fortran error.
    • Galaxev - need nice input dialogue boxes not just config file DONE (as far as possible with current CEA).
      • Clarified Python script wrapper now available
      • The output spectra at given ages is the most important output that we need so that it can be used with yafit. This uses the 'gpl' script to extract them using the wavelength range provided by the user. Currently, run via CEA, it returns a file but with no spectra in it.
  5. Selecting cosmology - OK? (PP please explain to AMSR!)
    • Anita, this is straight forward. Most observational papers in the introduction quote what cosmology they have used throughout the paper. This is all I mean here i.e. selecting the values for Hubble parameter, omegaMatter and omegaVacuum. Thus, given a redshift we can calculate the Luminosity distance, for example.
  6. Fitting - YAFIT
    • Check that handling/labelling of flux units is consistent PP/MT
      • Works OK for a comparison with Bruzual and Charlot models. It returns the correct model ( in this case based on the age of the input models). Paresh
    • Incorporation of user's own expressions OK
    • Is there any intention to provide YAFIT in AstroGrid?
-- PareshPrema - 07 Nov 2007
Topic revision: r8 - 2008-05-16 - 11:21:09 - AnitaRichards
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