Results of the verification of the NIR MOS EMIR

EMIR is one of the first common user instruments for the GTC, the 10 meter telescope operating at the Roque de los Muchachos Observatory (La Palma, Canary Islands, Spain). EMIR is being built by a Consortium of Spanish and French institutes led by the Instituto de Astrofisica de Canarias (IAC). EMIR is primarily designed to be operated as a MOS in the K band, but offers a wide range of observing modes, including imaging and spectroscopy, both long slit and multiobject, in the wavelength range 0.9 to 2.5 μm. This contribution reports on the results achieved so far during the verification phase at the IAC prior to its shipment to the GTC for being commissioned, which is due by mid 2015. After a long period of design and fabrication, EMIR finally entered into its integration phase by mid 2013. Soon after this, the verification phase at the IAC was initiated aimed at configuring and tuning the EMIR functions, mostly the instrument control system, which includes a sophisticated on line data reduction pipeline, and demonstrating the fulfillment of the top level requirements. We have designed an ambitious verification plan structured along the three kind of detectors at hand: the MUX and the engineering and scientific grade arrays. The EMIR subsystems are being integrated as they are needed for the purposes of the verification plan. In the first stage, using the MUX, the full optical system, but with a single dispersive element out of the three which form the EMIR suite, the two large wheels mounting the filters and the pseudo-grisms, plus the detector translation unit holding the MUX, were mounted. This stage was mainly devoted to learn about the capabilities of the instrument, define different settings for its basic operation modes and test the accuracy, repeatability and reliability of the mechanisms. In the second stage, using the engineering Hawaii2 FPA, the full set of pseudo-grisms and band filters are mounted, which means that the instrument is fully assembled except for the cold slit unit, a robotic reconfigurable multislit mask system capable of forming multislit pattern of 55 different slitlets in the EMIR focal plane. This paper will briefly describe the principal units and features of the EMIR instrument as the main results of the verification performed so far are discussed. The development and fabrication of EMIR is funded by GRANTECAN and the Plan Nacional de Astronomia y Astrofisica (National Plan for Astronomy and Astrophysics, Spain)