EMIR (Especrografo Multiobjecto Infra-Rojo) is the first second-generation GTC instrument to enter regular operations. It is a near-infrared (0.9 - 2.5 µm) wide-field imager and medium-resolution multi-object spectrograph installed at the Naysmith-A focal station. The center piece of the instrument is the CSU (Configurable Slit Unit) allowing to configure and observe in real time up to 55 slits over the 6.64' x 4' spectroscopic field of view. Long slits with different dimensions could be configured as well. The disperser elements are formed by combining high-quality diffraction gratings, manufactured by photo-resistive procedures with large conventional prisms. In imaging mode the 6.64' x 6.64' field of view could be observed through 11 narrow and broad-band filters (including the standard 2MASS JHKs). The detector is a 2048 x 2048 Teledyne HAWAII-2 HgCdTe near-infrared optimized chip with a pixel scale in imaging mode 0.2"/pixel. The EMIR project led by the IAC with the participation of the Laboratoire d'Astrophysique - Observatoire Midi-Pyrenees (France), Universidad Complutense de Madrid and the Laboratoire d'Astrophysique - Observatoire de Marselle (France).
The contribution of the