Reduction Information


Processing Images

When the image is read out, you can immediately display it; you'll see a gap in the display because you are reading out of both amps. To make a joined, trimmed up image, you'll want to do the following (in iraf, of course): Note that the 2amp.dat example file is for 2200x4200 images (the default), and you may want to alter as you see fit.

Zeropoint

Zeropoints will change, of course, but here's the zeropoint solution for the M filter from Spring 2004, using an instrumental magnitude zeropoint of 25:
m = 25 - 3.665 - 0.153*(secz) - 0.181*(B-V)

So 1 count per second is a magnitude of 25 - 3.665 - 0.153*1.0 - 0.181*1.0 = 21.001 (assuming unit airmass and a B-V color of 1.0).

So for a 900 sec exposures, and a pixel scale of 1.45 "/pix, this is equivalent to a surface brightness of
mu = 21.001 + 2.5log(900) + 2.5log(1.45*1.45) = 29.2 mag/asec2


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Last Updated: 18/4/04