Theoretical Data UCD Proposal

[Frederic V. Hessman]

> we want to start writing down a list of quantities for theoretical  
> data and then propose these quantities for inclusion into the UCD1+  
> controlled vocabulary.
> The ITVO group works on cosmological simulations and stellar  
> evolution models. As a first step these notes notes are dealing  
> with cosmological quantities.
> The underlying idea is to contribute to the
>
> http://www.ivoa.net/twiki/bin/view/IVOA/IVOATheoryGeneralRequirements
>
> discussion and, at the same time, suggest some ucds for simulated  
> data. We opened a wiki page where everyone can add missing  
> quantities and related ucds
>
> http://www.ivoa.net/twiki/bin/view/IVOA/TheoreticalDataUCDProposal
Too bad we're not further along with standard vocabulary formats -  
the simulation community could simply use standardized SKOS tokens like

	IVOAT:hubbleconstant	"Hubble constant"

	IVOAT:omegamass		"Omega(mass)"

	IVOAT:omegalambda		"Omega(Lambda)"

	IVOAT:sigma8			"sigma_8"

(where IVOAT: temporarily means http://www.Astro.physik.Uni- 
Goettingen.DE/~hessman/rdf/IVOAT#) and then define all the extremely  
specific vocabulary which nobody else needs.   See http:// 
www.astro.physik.uni-goettingen.de/~hessman/rdf/IVOAT/


> Other ucds we want to add (or ask attention for) are related to the  
> 'temperatures' used, for example in galaxy clusters simulations. we  
> think a good idea is to add ucds like
> phys.temperature.emissionweighted
> phys.temperature.massweighted
> phys.temperature.speclike
> following the idea of the existing .effective and .electron ones.  
> Another ucd, or ucd group, could be related with the 'critical  
> density' radius, adding the simple phys.radius.rhocritic and/or its  
> extensions to phys.radius.rhocritic.NNN (namely NNN=200, 500,  
> 2500). Maybe another choice for this problem could be something  
> like phys.size.radius;phys.cosmology.rhocritic which is better if  
> one wants to relate the critical density to other quantities than  
> the radius (let's say:
> phys.temperature.speclike;phys.cosmology.rhocritic)
This is a great example of where the centralized UCD approach is  
going to fail miserably - the IVOA can't possible agree to have a  
universal token for

	phys.radius.rhocritic.2500

I'm definitely not saying that the theory community doesn't need this  
token, I'm just saying that it shouldn't be the business of a  
centralized IVOA committe to make that decision.

> We also want to add other ucds like:
> - 'object.gas', 'object.stellar', 'object.darkmatter', ...and so  
> on, as
	IVOAT:darkmatter		"Dark Matter"

	IVOAT:stellarobjects		"stellar objects"

	....
(sigh) :-(

Rick