M106 is a fairly unique looking intermediate spiral galaxy in Canes Venatici.  The field of view is full of distant galaxies, in particular the cluster near the bottom of the image.  Arguably the most interesting part of M106 are the anomalous arms, just barely observable in this image.  Two arms are visible in the visual spectrum, but additional x-ray data reveals two more arms nearly perpendicular to the visual two.  A well validated theory published in 2001 determined that the origin for these anomalous disks is highly correlated with the jet (observable in radio data) emitting from the supermassive black hole at the center of M106.  This jet superheats gas in its line of travel causing propagating shockwaves and the energetic emission of x-ray and ionized gas photons.  These expanding shockwaves are the source of the shape of the anomalous arms! 

To be fully transparent, this data is the actual first light from the CDK17 at its new site.  Processing was put on hold as camera settings on the QHY600 proved to be a bit of a problem.  The camera was previously being shot in bin 2x2 due to atmospheric constraints.  The QHY method of binning is the simple numerical summation of the NxN pixel array into a single value - with no dividing step afterwards.  This isn’t the best approach and is coupled with the QHY documentation mentioning the creation of synthetic 18 and 20 bit images but this is a side discussion.  We’ve been shooting the 600m in High Gain Mode (1), gain 0 to maximize full well and dynamic range at the expense of non optimal (but still reasonable) read noise.  In order to fully take advantage of the new site, we decided to try shooting short frames, 120s, to try and really chase maximum resolution.  The challenge here is that at 120s, the read noise wasn’t being sufficiently swamped and wasn’t getting sufficiently decreased as it had been when binning 2x2.  All of this resulted in the final integrated image demonstrating a background value of 0.000X.  This exceptionally low value wasn’t easily correctable with a pedestal as nothing was getting zero clipped.  Extreme care had to be taken during background extraction and stretching to avoid destroying the data. 

Lessons have been learned, gain has been bumped to 56 for the next dataset currently being shot. Short frames did pay off though!  A strict FWHM threshold was set and the final median luminance master came out to around 1.8”.  The final editing challenge was an absolutely nasty reflection in the R channel near the top of the image, fixed with the much appreciated help of Greg Turgeon! 

Enjoy! 
Michael and Jonathan Norman