EMIR is the NIR imager and multi-object spectrograph common user instrument for the GTC and it has recently passed its first light on sky. EMIR was built by a Consortium of Spanish and French institutes led by the IAC. EMIR has finished its AIV phase at IAC facilities and it is now in commissioning on sky at GTC telescope, having completed the first run. During previous cool downs the EMIR subsystems have been integrated in the instrument progressively for verifying its functionality and performance. In order to fulfil the requirements, prepare the instrument to be in the best conditions for installation in the telescope and to solve unexpected electronics drawbacks, some changes in the implementation have been accomplished during AIV. In this paper it is described the adjustments, modifications and lessons learned related to electronics along AIV stages and the commissioning in the GTC. This includes actions in different subsystems: Hawaii2 detector and its controller electronics, Detector translation Unit, Multi object slit, wheels for filters and grisms, automatisms, vacuum, cryogenics and general electronics.
We report the results on the EMIR1 (Espectrógrafo Multiobjeto Infra-Rojo) performances after the commissioning period of the instrument at the Gran Telescopio Canarias (GTC). 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 Astrofísica 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. The development and fabrication of EMIR is funded by GRANTECAN and the Plan Nacional de Astronomía y Astrofísica (National Plan for Astronomy and Astrophysics, Spain). After an extensive and intensive period of system verification at the IAC, EMIR was shipped to the GTC on May 2016 for its integration at the Nasmyth platform. Once in the observatory, several tests were conducted to ensure the functionality of EMIR at the telescope, in particular that of the ECS (EMIR Control System) which has to be fully embedded into the GCS (GTC Control System) so as to become an integral part of it. During the commissioning, the main capabilities of EMIR and its combined operation with the GTC are tested and the ECS are modified to its final form. This contribution reports on the details of the EMIR operation at the GTC obtained so far, on the first commissioning period.
EMIR1,2 (Espectrógrafo Multiobjeto Infra-Rojo) is a wide field multi-object spectrograph already installed in the Nasmyth focus of GTC (Gran Telescopio Canarias). It operates in the near-infrared (NIR), in the wavelength range from 0.9 μm to 2.5 μm and it will include several mechanism working in cryogenic conditions.
A key component of EMIR is the CSU (Configurable Slit Unit), which is a robotic cryo-mechanism used to generate a multi-slit configuration and a long slit on EMIR focal plane when working in spectroscopic mode. The system has 110 sliding bars which can be configured at cryogenic working temperature to create up to 55 slits with a high position accuracy and repeatability. The movement of the bars is performed by an actuator which allows reaching a relatively high speed for the coarse movement and controllable steps up to 2 microns for the fine positioning. This subsystem has been designed and manufactured by the Dutch company Janssen Precision Engineering (JPE) and the Spanish company NTE-SENER. Afterwards, it was thoroughly verified at the IAC (Instituto de Astrofísica de Canarias) facilities.
In this paper, the CSU will be briefly described. One of the more important parts of the CSU is the actuators, which move the bars by means of a stick-slip effect. A set of tests designed for characterizing and improving the robustness and performance of the actuators will be presented. Finally, an overview of the current CSU performance will be presented.
EMIR is a second generation GTC instrument. EMIR's external structure is a huge cylindrical vacuum chamber of 2.2m
length and 1.8m in diameter with a weight of around 5 tons, with the instrument inside on a floating optical bench at the
LN2 temperature in a cryogenicaly poumped system. The instrument is mounted on the optical bench over a double cold
The verification of the optical system and its alignment on the optical bench, as well as the alignment of the optical axis
with respect to the vacuum chamber and the whole set to the rotator, are the critical tasks that will validate the feasibility
and functionality of this instrument.
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 Astrofísica 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 Astronomía y Astrofísica (National Plan for Astronomy and Astrophysics,