bandpasses in RM

[Anita Richards]

Hi,

First, it's good to see Bob's document (sorry Bob, you have to take most
of the credit, the rest of us should get the blame for muddying the
waters). I kept out of the debate because I had more than my go last year
and the present version seems just right for the present time.

There have been suggestions made which will be important in the long term
(i.e. years) and I have a comment for the next round (which everyone will
have forgotten by then).

I think that how data are collected _is_ a factor, as is the number of
catalogues and other data resources involved including publications, per
spectral division.  The purpose of the Registry is not to be a model of
symmetry and logic (although it helps human maintainers if the structure
is not too arbitrary). The purpose is to help users find data.  So it
makes sense to divide approximately along the lines of where data are
provided from (which archives to search, which catalogues) and what
researchers think of in the appropriate labels.  We also don't want to
have to search too many resources in one group, or too many groups for one
query.  Of course, some archives and many queries are multi-wavelength and
many categories overlap, but the present division seems to be reasonably
close to an even spread across the current science cases I know of from
AVO and AstroGrid, apart from the UV and gamma rays - but that is a
deficiency of the science cases or maybe of archive availability.

In the longer term:

When I proposed dropping EUV last year, there were objections from the
solar community.  However we are not catering to them much anyway - but we
shouldn't forget them.  So perhaps we will need to reinstate that category
- and create a separate decametre category - when we do include solar/STP
work.  But for now there are too little data available to astronomers to
be worthwhile.

Similarly, there will be a flood of data from ALMA in a few years time,
and even before that, I hope that the involvment of the JACH in RadioNet
will lead to more JCMT and SCUBA data being available from VOs - but at
present millimetre covering the whole range is underpopulated.

Finally, Nic is right about Astroparticles - how are these usually
described?  Are these usually in the gamma ray energy range?  Do we serve
these data?  Could they be served by the gamma ray energy range until a
fuller definition is obtained?

In short, the bandpass definitions should be science-case-driven; the
present divisions meet the present science case needs as far as I am
aware, and we should come up with the science cases before we attempt
re-definition - in several years' time!

cheers
a

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Dr. Anita M. S. Richards, AVO Astronomer
MERLIN/VLBI National Facility, University of Manchester,
Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, U.K.
tel +44 (0)1477 572683 (direct); 571321 (switchboard); 571618 (fax).