28 Feb 2005

It has recently been determined that all spectral flats using the low resolution 10um grating obtained prior to Feb 27, 2005 were saturated. This means that:

1. all unratioed spectra that have been flatfielded prior to then have incorrect spectral shapes;
2. all spectra of extended sources that were ratioed by spectra of a point source (std) have incorrect shapes.

These differences are not huge, but are noticeable.

Note that reduced spectra for which the spectrum of a point source target was ratioed by the spectrum of a point source standard, both measured in the same or nearly the same array rows, are unaffected and OK.

If you have old Michelle spectral data and would like an unsaturated flat to use in re-reducing those data, please contact Tom Geballe or Scott Fisher.

Last update Feb 28, 2005; Tom Geballe and R. S. Fisher