3946.097 line not reliable for calibration ?

Forums Spectroscopy What wavelength error is acceptable with an Alpy? 3946.097 line not reliable for calibration ?

Robin Leadbeater

Hi David

“Including the 3946.097A line gives a considerably worse fit at the blue end.” 

I have had a look at the high resolution echelle spectrum of the lamp that Shelyak use in Richard Walker’s atlas. (plate 98 order 57)  The 3946.097 Ar line that ISIS uses for a lamp line fit with the ALPY is in fact a close triplet 3946.097, 3947.505, 3948.979  so definitely incorrect.  I don’t think this is connected with what John is seeing but I suspect this may be the cause of my increasing error towards the blue using just the lamp calibration.

I took a spectrum of MILES star HD206165 last night to experiment with. It is a B2i star so lots of narrow H and He lines which hopefully should show up any errors