bandpasses in RM

[Doug Mink]

Andy Lawrence replied to Arnold Rots comment (in quotes)

> *In principle I agree with the seven, but wonder where submillimeter
> *falls and whether radio ought to be differentiated.  I mean, otical
> *covers just one octave, while radio comprises at least 10 octaves...
> *The distribution seems rather uneven.
> 
> as an X-ray astronomer in origin I agree in principle; we tend to refer
> to the "UVOIR" to mean anything from 10 micron to 0.1 micron. Also I am
> personally scientifically in favour of highlighting the submm ... BUT ..
> 
> .. we are not talking about density of wavelength pixels, but density of
> people and papers. My guess is that Bob's scheme gives a fairly uniform
> distribution of people-hours. So I vote for Bob's list.

I don't know about millimeter vs. radio, but here at SAO there are quite a
few submillimeter astronomers.  I think the split shouldn't be by how many
papers are produced, people are working, or data are produced, but by whether
the instrumentation, data, and science are different from other wavelength
regimes.  I posed this question to Matt Ashby, who has been representing the
submillimeter regime on our local VO committee, and here is part of his
response:

> 	My feeling is that there are nuances of meaning between the
> submillimeter and millimeter designation -- at the least, my experience
> tells me that in the submillimeter regime one tends to focus on line
> emission whereas at the longer wavelengths one tends to do a combination
> of line emission and continuum emission work.  That's my limited
> experience, anyway.  The physics being studied is not so different but the
> instrumentation tends to be.  However the focus at submm wavelengths has
> historically been very different from the far-infrared, which (except for
> ISO) has not had good instrumentation available to do spectroscopy.
> 
> 	All in all, I think it is not unreasonable to combine mm and submm
> into one category, but you should at least label it clearly.  Why not call
> it Millimeter/Submillimeter?  We have two local observatories (SMA,
> SWAS) that would seem to deserve some emphasis there.

As to where the boundary between submm/mm and IR should be, he noted:

> 	You would not want to combine submm and infrared though -- too
> many decades in frequency there I think.  K-band and SMA data would not
> really fall into the same category; they trace different types of physical
> processes.
> 
> 	Just a note: I would agree with you that .1 mm is far-infrared.
> But where, say, SWAS works (.5 mm) is generally agreed to lie in the submm
> regime, and I think that's pretty much the conventional wisdom.  In fact
> I'd draw the boundary by reference to Spitzer, and take anything at 160 um
> and shorter wavelengths as infrared and call the longer wavelengths part
> of the submm regime.  The longest-wavelength detector on Spitzer is at 160
> um and is widely referred to as far-infrared, and this will be a de-facto
> standard of nomenclature now that Spitzer's results are about to find
> their way into the published literature.

-Doug Mink
  Telescope Data Center
  Harvard-Smithsonian Center for Astrophysics