Ecart de continuum

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Michel Tasse
Posts: 39
Joined: Wed Oct 21, 2020 9:24 am

Re: Ecart de continuum

Post by Michel Tasse »

Robin Leadbeater wrote:Hi Michel,

Here are my files(zip file attached.) Which one is different to yours ?

(I smoothed the MILES spectrum in the posted image to match the resolution of the Pickles spectrum and I still use ISIS 5.9.3 because I prefer that it corrects for the black body curve of the flat lamp but that should not be important here)

Cheers
Robin
Hi Robin,
Thank you for your answer.
For the comparison between the Pickles profile and the hd207260_miles_ISIS you sent me and mine: they correspond exactly
(with Y Offset=0.01 for readability):
Comparison(Y_Offset=0p01)_a2i_pickles_isis.fit_&_a2i_Pikles_normalisee5650-5665A .JPG
Comparison(Y Offset=0p01)_hd207260_miles_&_hd207260_miles_isis.JPG
For the comparison between the profile “hd207260_miles_isis_dered_0p47” that you sent me and my profile “HD207260_Miles_derougie E(B-V)=0p47_normalisee”, there is a visible difference:
Comparison HD207260_Miles_derougie E(B-V)=0p47_normalisee & hd207260_miles_isis-dered_0p47.JPG
It seems that with the same E(B-V)=0.47, the development operation performed is not identical.
Would it come from the calculation process for dered, or the ISIS version? I used the “Extinction” tab below:
HD207260_Miles for Dered 0p47 (tab Extinction)_with_ISIS-V6.1.1.JPG
HD207260_Miles for Dered 0p47 (tab Extinction)_with_ISIS-V6.1.1.JPG (48.6 KiB) Viewed 3144 times
I wanted to do the same tests with your ISIS 5.9.3 version, but I didn’t find it on the Internet.

If necessary, attached my compressed files:
hd207260_fits_files_MT.7z
(24.54 KiB) Downloaded 126 times
Cheers.
Michel
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
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Re: Ecart de continuum

Post by Robin Leadbeater »

Yes it looks like there has been an undocumented change in the way ISIS calculates the extinction.
http://www.spectro-aras.com/forum/viewt ... =10#p17284
I have opened a new thread here to see if anyone has more information
http://www.spectro-aras.com/forum/viewt ... =48&t=3031

Cheers
Robin
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Michel Tasse
Posts: 39
Joined: Wed Oct 21, 2020 9:24 am

Re: Ecart de continuum

Post by Michel Tasse »

Thank you very much Robin for your help and all your explanations.
I’ll follow the new thread you just opened.
Cheers.
Michel
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