Normalisation of MILES spectra in the ISIS database

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David Boyd
Posts: 161
Joined: Wed Dec 11, 2013 5:50 pm

Normalisation of MILES spectra in the ISIS database

Post by David Boyd »

In the previous version of the ISIS database, MILES star spectra had all been normalised (intensity set to unity) at the same wavelength. In the current version of the database, this is no longer the case and spectra have been normalised at different wavelengths.
Miles star profiles.png
Miles star profiles.png (143.45 KiB) Viewed 1996 times
A consequence of this is that the compare function in ISIS may not align the target and reference star spectra at the same level in intensity, unless the two spectra happen to have been normalised at the same wavelength. While the normalisation wavelength of the target spectra can be set by the user, this is not the case with the MILES spectrum. This makes the compare function much less useful.

David
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
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Re: Normalisation of MILES spectra in the ISIS database

Post by Robin Leadbeater »

I suspect this may be because the current database is based on the Interstellar Extinction corrected spectra from MILES which were then reddened but perhaps not rescaled. The original database used the original MILES non IS corrected spectra.

E(B-V)
HD192640 0.03
HD013267 0.42
HD209975 0.39
HD143807 0.02

Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
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