Re: T0: UCDs for "em" & "spect"

From: Matteo Guainazzi <Matteo.Guainazzi-at-sciops.esa.int>
Date: Mon, 13 Jun 2005 09:48:40 +0000


Dear Miguel, dear Andrea,

 from the X-ray perspective, I confirm basically Miguel's findings. The terms "soft", "medium", "hard" X-rays have been and are being used with very different meanings in different papers. What is "hard" for XMM-Newton and Chandra (2 to 8, 10 or 15 keV), was called sometimes
"intermediate" in BeppoSAX papers. Moreover, I have almost never seen
"medium" in a published paper.

 There are two possible ways out:

 The consequences of either choice are clear: in the former, we risk mis-understanding old surveys (those done when I was not born, but still in use), in the latter we multiply we number of UCD endlessly.

 None of the above solutions is therefore satisfactory, from my point of view. As often in the VO context we are trying to extract order from chaos, i.e. one to derive standards where standards have never been applied in the past.

 My favorite (and surely controversial) solution? A more conservative and radical (!) approach: we remove "soft", "medium" and "hard", and keep only "em.X-rays".

 Regards, Matteo

-- 
Matteo Guainazzi
XMM-Newton SOC				Matteo.Guainazzi-at-sciops.esa.int
European Space Astronomy Center	of ESA	Phone:     +34 91 8131 176
VILSPA, Apartado 50727, E-28080 Madrid 	Fax:       +34 91 8131 172         
Received on 2005-06-13Z11:49:11