agreed, there is some residual noise, in this case 1.3 electrons RMS per pixel for every read action - and there is also some dark current of about one electron every minute or so - there is no other noise at all (apart from shot noise in the signal). The resistor white noise that you mention is the dark current, and it is negligible due to cooling. Amplifier noise is incorporated in the read noise and, because the pixel-level charge amplifiers are part of the cooled chip, they are very quiet. Because the signal is amplified before it gets off the chip, it is well above any electronic noise in the output circuit, so you actually do end up with almost zero noise. The huge CMOS advantage of having pixel-level amplification was also it's main downfall, because the gains and offsets of the amps varied, introducing fixed pattern noise. The new CMOS chips harmonise the amps, giving very low-noise high-quality images and blistering download rates - well suited to lucky imaging.
The new chips are not sCMOS, but they are getting close to that regime
http://www.andor.com/learning-academ...mos-read-noise