T0: UCDs for "em" & "spect"
mcs at iaa.es
Fri Jun 10 09:01:14 PDT 2005
Hi again :)
>> ... for clarity purpose and hogenity
>> the UDCs I would suggest the following changues:
>> em.IR.K --> em.IR.2-3um
>> em.IR.H --> em.IR1500-2000nm
>> em.IR.J --> em.IR1000-1500nm
> may be we should go this way, because the names of those bands can be
> In the case of x- and gamma-rays though there is no confusion, so I
> keep the existing names...
Uhmm, for X-ray and gamma-rays I was asking X-ray and gamma-ray
I know that UCDs are not for humans, but asking about what soft and
hard X-rays mean,
the answer is highly dependent on the asked astronomer. Usually they
talk only about
soft and hard. "medium-Xrays" is not understood. In fact, most people
I asked consider
hard X-ray as aprox 4-10 keV band (from maximmun energy from ROSAT/
EINSTEIN to max energy by CHANDRA/ASCA/XMM)..... I do not know, but I
keep em.X-ray.soft medium and hard is misunderstanding for X-ray
people. Another example,
ROSAT has a "hardness" ratio that is 0.2 keV-1.5keV (soft) vs. 1-4kev
(hard) (I do not remember exactly the
energies, sorry) where "soft" and "hard" refers to the detectors in
ROSAT (but they are used in thsi way in the articles)....
In gamma ray, the situation is similar. You can take a look the
INTEGRAL instruments, or CGRO ones.
The problem is that each energy range use techniques completely
different (due to the physics of the process) and em.gamma.hard is to
wide! It includes from only space instruments to only ground based
instruments (using the atmosphere as detector). In fact some gamma-
ray people make distinction between gamma-ray VeryHigh gamma-rays and
Ultra-High gamma rays as clearly different parts of the
electromagnetic spectrum.... (I was also thinking about INTEGRAL
where a more defined bands
would be and asset).
>> Finally, I think that the inclusion of em.line would be useful, but
>> only for a very sort list of lines so ... I would agree with
>> Hydrogen lines, but I do think that em.line.OIII should be
>> depreciated (there is several OIII lines!, and if OIII is here, by
>> not, O I, or H+K Ca II etc...? so I propose depreciate
>> em.line.OIII ...
> the reason for the inclusion of the OIII line is that the doublet
> is one of the strongest lines in emission-line objects (second only to
> Halpha in most cases). There are surveys in Halpha/beta and in
> OIII, not in
About other issues. I also agree with include arith and stat in
"math". I also suggest
that means the order moment of the statistical distribution, i.e.
mean is 1,
variance is 2, skewness 3, and kurtosis 4....), so allows to include
more statistical information
(e.j. there is some published data in skewness distributions of
globular cluster, also are useful
for some synthesis models)
In the case of:
>> spect I worry about spect - this is a kind of data.
>> If spect, why not image? I predict a few years from now
>> we will have to change spec and instr.image to
>> data.spect, data.image, etc.
> I agree that data.image and data.spec is a much better model, at
> least for observations. After all, what UCD
> often does is to provide generalized "keywords" a la FITS.
> On the other hand, the VO theory people might complain that their
> "images" and "spectra" are not really "data".
> Sounds like a problem which has to be put off until later.
Form a theoretical point of view (mine) theory results can be
considered as "data", produced by a computer
instead a telescope but.... (any case the results of theory will be
also under a tag <TABLEDATA> isn't it?
(it is my very particular opinion). (any case there is also a S UCD
Finally, about the "line" atom used in "spect"... Uhmm, I do not know
if there is a more usefull atom. I mean, some lick indices, as
example, are obtained from "bands" and no lines.... there is no
problem is it is explicti in the definition that it would refers not
only to lines but also to bands...
In the same way, I think that
spect.line.intensity ---> spect.line; phot.fluxDens
Atoms like: profile. width, eqwidth sound ok, but
spect.line.asymmetry is not included in spect.line.profile?
also for spect.line.broad? (this last I am not sure)
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