[obs-tap] Spectral axis - meters

Petr Skoda skoda at sunstel.asu.cas.cz
Mon Mar 28 07:40:46 PDT 2011


I do not understand what is the meaning of B2.2. (Spectral Bounds):
"Such values (it is meant spectral intervals) are expressed as frequencies 
but using meters as units as it is easily convertible"

In stellar astronomy tehe spectral interval is in A or nm - and after some 
experiences with  SSA clients (e.g. in BAND=4583e-10/6600e-10) the meters 
are already well accepted by the community.

So the above statement referes mostly to radioastronomy (probably) as 
the X-ray community preferes keV (energy).

The Arnold's suggestion to keep Hz I feel strongly radio-centric.
IF we have to keep one units (BTW WHY ???? I would put a reference to 
section 17 (Spectral Bounds)) and leave the words about frequencies and 
easy convertibility .

Just comment to the meter/Hz issue - in simplified terminology about EM 
spectrum the wavelength is the more general and easily understood concept 
- even for radioastronomy (we have submm range and decimeter and decameter 
ranges and we have microwaves and milimeter wave bands etc ...
Its dificult to find reference to observation in THz band or something 
like this....



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*  Petr Skoda                         Tel   : (323) 649201, l. 361      *
*  Stelarni oddeleni                          (323) 620361              *
*  Astronomicky ustav AVCR, v.v.i     Fax   : (323) 620250              *
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*  Ceska republika                                                      *
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