Extremely Large Telescope

Abstract:

Near infrared instrumentation at 4 and 8 meter class telescopes has grown rapidly in the past few years with the advent of 1024(2) and 2048(2) detector arrays. We present a brief review of high resolution spectroscopic capabilities available worldwide, with an eye on new developments, e.g. spatially resolved spectroscopy offered by integral field instruments.Observing at near-infrared wavelengths has its own quirks. We discuss observing strategies to get past the limits of high background (including both thermal background and background due to OH sky emission lines), Variations in atmospheric transmission, and detector constraints. Special attention is given to the subject of OH suppression/avoidance, which can significantly increase the sensitivity in the J, EI and short K windows. This is especially important for (fainter) high redshift targets, where the rest frame visible diagnostic lines are shifted into the near infrared.