A modification for improve eShel spectrograph

[James Foster]

Here is my latest spectrum of Vega, response corrected with the eShel2:


Note that the "Pickles" A0V spectrum I used for my image response curve is low resolution and goes just short of 8405A,
but this is good enough to see if the spectrum is radiometrically accurate on the balmer lines and it seems like it is.

I will re-image a A type star in the NOAO Indo-US Library (CFLIB) catalog to get a better image response curve. Progress was
also made to optimize the ISIS eshel bin (16 to 13 pixels high), which increased the resolution slightly and lowered
the noise(ThAr image centered on Order 34):


Now to reduce non-vega eShel spectra!

James

[Joan Guarro Flo]

Hi James,

These last few days I'm wondering if you have resolved the possible low sensibility of your equipment.

One possible origin would be the optical fiber and how you use it, - really I don't know -, but, in this way I leave here the link of CAOS web, https://spectroscopy.wordpress.com/fibres/

You can read in its OPTICAL FIBRES corner a precise and extend explatations by Carlos Guirao, he was worked as an optical engineer in the European Southern Observatory ( ESO ) in Garching, ( Germany ),for a lot of years and joint other authors designed the spectrographs that sell the prestigious German company Baader Planetarium. I hope that it will be useful for you.

Cheers, Joan.

[James Foster]

To: Joan,

Sorry for the late reply. I was in the middle of selling and buying a house this May-June and now I'm more settled down.
I don't have a quick answer, but I will take the eShel commissioning-up as soon as I construct my new location's roll-of-roof for my CDK17.

My Sky is much darker (I'm 15-17min away from the Mt. Pinos Parking lot at 2500m) and my altitude at this new home is still about 1700m, 150 kilometers
NNW of downtown Los Angeles, so I will have a much darker sky to take spectro! (every clear moonless night the Milky way is very spectacular!).
Only downside is, is does snow here in the winter.....

James Foster
Frazier Park, CA

[Joan Guarro Flo]

HI James,

Don't worry, I am delighted reading your text and deduce that you have made a huge job that needs a very high dose of will and effort.

I hope that you'll explain to us the different stages that you get and send some pictures of that.

So I wish you great success, because I think that all of us will win with it.

Cheers !! Joan.