The spectrograph detector NIRES is a 2048 x 2048 Teledyne H2RG array. Only two quadrants of this detector are active covering a region 2048 x 1024 pixels. The detector is read by 16 amplifiers.


The inverse gain applied to the detector has been calculated to be 3.8 e-/ADU.

The following plot shows the variance curve for this H2RG.

Variance Curve


The Readnoise that we have measured to be 14.5 e- per CDS. This is the maximum value obtained among the 16 amplifiers. As expected the readnoise improves as a function of Fowler reads.

The following plot shows the read-noise (average over all amplifiers) as a function of Fowler reads.


The detector is linear up to 35000 ADU (deviation < 10% in ADU). The full well is 150000 electrons.

Dark Current

In order to determine the internal background, we selected a region of the H2RG not exposed to the cross-dispersed orders and free from internal reflections and light leaks. We measured an internal background of 0.13e-/sec.

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