Euclid: Pixel-to-pixel readout noise correlation in HAWAII-2RG detectors☆

We investigated the pixel-to-pixel noise correlations of HAWAII-2RG (H2RG) detectors using data from preflight testing performed for Euclid. We find that the detectors - in the absence of input signal, with and without the focal plane electronics that will be used on board Euclid - carry pixel-to-pixel noise correlations with varying amplitude across our sample of 23 detectors. We find a baseline level of order 10%, but with variations among detectors and portions of a given detector. We also observe occasional, significantly higher levels, which we attribute to fluctuations in alternative column noise. These fluctuations affect approximately a tenth of the total number of exposures and result in Pearson correlation coefficient values as high as 40% for the worst cases. While our sample of detectors is specific to Euclid, we expect our results to apply in general to the family of H2RG detectors, widely used in infrared astronomy.