Spectra DM for theoretical spectra?
awicenec at eso.org
Wed Jun 3 07:37:40 PDT 2009
I think there is a problem here getting observational and theoretical data
together. Lets start with a use case:
A user is interested in comparing the observed spectra of a star with the
appropriate theoretical spectrum derived from some model.
The key here is to find what is appropriate! The input to the query for such a
theory spectrum service is actually the output of a fairly complex reduction of
the observed spectrum. Essentially the observed spectrum has to be reduced to
the level where you know Teff, LogG, Metallicity (to name just a few), else it
is impossible to search the theoretical service. People are actually doing some
other tricks as well and perform quite complex spectrum matching algorithms
using template spectra databases in order to derive parameters like to ones
above from observed spectra.
Anyway the input parameters (and thus the model) for a theory spectrum service
for stars would be quite different from the ones for quasars, galaxies or
molecular clouds. Thus I think the only way to get around this is to leave the
definition to the service itself, much the way Gerard described it during the
interop. I think the only thing we could eventually define in the model is
service types, i.e. theoretical stellar spectra, theoretical quasar spectra,
theoretical gamma ray burst spectra... This obviously goes back to astronomical
Pierre Didelon wrote:
> Carlos Rodrigo Blanco wrote:
>> I think that there is a minimum set given by:
>> Teff: effective temperature of the star
>> Logg: logarithm of the gravity
>> Metallicity (for some authors this is the fraction of elements heavier
>> than Hidrogen and for other it is something different,
> He abundance,
> s element abundunces
> p element abundances
> or even more precise things
>> I can ask for a better definition to some real astronomer :-)
> am I reel?
> or a virtual astronomer :-\
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