<div dir="ltr"><div>FWIW, a good principle for IVOA is to make specifications as general as possible for application across all subcommunities.</div><div>If we are talking about the spectral coordinate axis, frequency and energy make much more sense than wavelength.</div><div>Wavelength, for most of us, just runs the wrong way.</div><div>For energy one could use the eV as the basic unit, but using Hz for frequency
probably
makes more sense.</div><div>That should feel natural for radio and HEA and indeed the physical quantity of the spectral axis increases as the numbers get bigger.<br></div><div>Powers of 10 can easily be avoided by using the usual prefixes.</div><div><br></div><div>Cheers,<br></div><div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><br><div dir="ltr" style="margin-left:0pt"><table style="border:medium none;border-collapse:collapse"><colgroup><col width="445"><col width="275"></colgroup><tbody><tr style="height:90pt"><td style="border-color:rgb(255,255,255);border-style:solid;border-width:1pt;vertical-align:top;padding:5pt"><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><span 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Neves, Margarida <<a href="mailto:mcneves@ari.uni-heidelberg.de">mcneves@ari.uni-heidelberg.de</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
Hi,<br>
<br>
>> Hello, <br>
>> <br>
>> Following Margarida nice presentation about LineTAP, here are some comments and questions. <br>
>> <br>
>> 1 - Choice of units for energy levels<br>
>> I saw that Joule was proposed. Joule is a bit a strange unit for energy levels because 1 Joule is lot of energy whereas rotational levels or hyperfine structures contains very few energy. Using Joule means that we will have to manipulate quantities as 10E-XX where XX is a lot. <br>
<br>
in my former answer I mistakenly read the comment about a proposal for joule for wavelength, and you’re talking about energy levels. Sorry,<br>
please do not consider this part of my answer. I need to get more sleep :)<br>
<br>
<br>
Margarida<br>
<br>
—<br>
<br>
Margarida Castro Neves<br>
<br>
German Astrophysical Virtual Observatory (GAVO)<br>
Astronomisches Rechen-Institut (ARI)<br>
Zentrum für Astronomie, Universität Heidelberg (ZAH)<br>
Mönchhofstr. 12 - 14, 69120 Heidelberg<br>
phone +49-6221-54-1891 fax +49-6221-54-1888<br>
<a href="mailto:mcneves@ari.uni-heidelberg.de" target="_blank">mcneves@ari.uni-heidelberg.de</a><br>
<a href="http://www.ari.uni-heidelberg.de" rel="noreferrer" target="_blank">http://www.ari.uni-heidelberg.de</a><br>
<br>
<br>
<br>
<br>
<br>
<br>
</blockquote></div>