P. Redondo

EMIR: the GTC NIR multi-object imager-spectrograph

In this contribution we review the overall features of EMIR, the NIR multiobject spectrograph of the GTC. EMIR is at present in the middle of the PD phase and will be one of the first common user instruments for the GTC, the 10 meter telescope under construction by GRANTECAN at the Roque de los Muchachos Observatory (Canary Islands, Spain). EMIR is being built by a Consortium of Spanish, French and British institutes led by the IAC. EMIR is designed to realize one of the central goals of 10m class telescopes, allowing observers to obtain spectra for large numbers of faint sources in an time-efficient manner. 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 present status of development, expected performances and schedule are described and discussed. This project is funded by GRANTECAN and the Plan Nacional de Astronomía y Astrofísica (National Plan for Astronomy and Astrophysics, Spain).

Structural and thermal analysis of EMIR

This paper shows the different design concepts and techniques employed in the structural and thermal analysis of EMIR (Espectrografo Multiobjeto Infrarrojo), nowadays under development at the Instituto de Astrofisica de Canarias.

EMIR mechanical design status

EMIR is the NIR multi-object imager and spectrograph for the GTC (Gran Telescopio Canarias). The instrument PDR phase was held successfully in March 2003, and we are at present in the middle of the ADR (Advanced Design Phase) during which a number of mechanical concepts will be tested on development prototypes to ensure the feasibility of the PDR proposed design. This presentation contains a technical description of the mechanical design of the instrument, as well as the prototypes development. The mechanical design is essentially built around the optical layout by providing an optical bench for mounting the optomechanics, the mechanisms and the detector, all this inside a custom-designed vacuum vessel and with the corresponding cooling system. One of its main design features is the use of a cryogenic reconfigurable slit mechanism to generate a multi-slit configuration, a long slit or an imaging aperture at the telescope focal plane. This feature will permit to maintain the instrument in operation conditions for a long time and take advantages in both a classically scheduled and a queued service observing schemes

Status of the EMIR mechanical system

EMIR is the NIR multi-object imager and spectrograph for the GTC (Gran Telescopio Canarias). The instrument ADR (Advanced Design Review) was held successfully in March 2006. During the AD phase, a number of mechanical concepts were tested on development prototypes to ensure the feasibility of the PDR proposed designs. This presentation contains an overview of the current mechanical status of the instrument, as well as the prototypes development. It contains the prototype tests results of the collimator first lens barrel, the support trusses, the grisms wheel and the demonstration programme for the cryogenic reconfigurable slit mechanism.

EMIR: THE GTC NIR MULTI-OBJECT IMAGER-SPECTROGRAPH

no nal global y el desempe~ de EMIR, el espectr ografo para objetos m ultiples del NIR del GTC, como tambi en el plan para su aplicaci on cient ca inicial. EMIR, actualmente en sus fases nales, ser a uno de los primeros instrumentos para usuarios del GTC, el telescopio de 10 metros en construcci on por GRANTECAN en el Observatorio del Roque de los Muchachos (Islas Canarias, Espa~ A EMIR lo construye un consorcio de institutos espa~ y franceses conducido por IAC. EMIR est a dise~ para llevar a cabo uno de los objetivos centrales de los telescopios de la clase de 10 metros, lo que permitir a a los observadores obtener espectros de gran n umero de objetos d ebiles de una manera ecien te en cuanto al tiempo. EMIR est a dise~ para ser operado primariamente como un MOS en la banda K, pero ofrece adem as un amplio rango de modos observacionales, incluido imagen y espectroscop a, tanto de rendija larga como de objetos m ultiples, en el rango de longitudes de onda de 0.9 a 2.5 m. Se encuentra equipado con dos subsistemas novedosos: una m ascara de rendijas m ultiples rob otica recongurable y elementos dispersivos formados por una combinaci on de rejilla de difracci on y prismas convencionales de alta calidad, ambos localizados en el coraz on del instrumento. Se describe y discute el estado actual de desarrollo, el desempe~ esperado, el calendario y los planes de aplicaci on cient ca. Este proyecto est a nanciado mayormente por GRANTECAN y el Plan Nacional de Astronom a y Astrof sica de Espa~ na.

The optical AIV of the infrared multi-slit spectrophotometer for GTC, EMIR

EMIR is a second generation GTC instrument. EMIRs 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 base. 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 electronics and mechanism control

EMIR is a multiobject intermediate resolution near infrared (1.0-2.5 microns) spectrograph with image capabilities to be mounted on the 10m Gran Telescopio de Canarias (GTC), located on the Spanish island of La Palma. This paper shows an overview of the EMIR electronics and mechanism control. First, a description of the detector (a Hawaii-2 array) electronics is given, which involves the use of commercial components (resistors, capacitors and operational amplifiers) working under cryogenic conditions (around 77K). This paper describes the particularities of the cold electronics, showing the problems found and the way to solve them. Preliminary results of the detector characterization are also presented in this paper. Secondly, an overview of the different mechanisms of the instrument is presented. They are cryogenic mechanisms with pretty stringent positioning requirements. The technological solutions used to meet the tight control requirements will be described.

LIRIS (long-slit intermediate-resolution infrared spectrograph): project status

LIRIS is a near-IR intermediate resolution spectrograph with added capabilities for multi-object, imaging, coronography, and polarimetry. This instrument is now being constructed at the IAC, and upon complexion will be installed on the 4.2m William Herschel Telescope at the Observatorio del Roque de Los Muchachos. The optical system uses lenses and is based on a classical collimator/camera design. Grisms are used as the dispersion elements. The plate scale matches the median seeing at the ORM. The detector is a Hawaii 1024 X 1024 HgCdTe array operating at 60K.

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 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, Spain).

SMART-MOS: a NIR imager-MOS for the ELT

We are currently developing a conceptual design for a future ELT NIR large field of view imager-spectrograph, SMART-MOS, along with several science cases from which top level instrument requirements are being established. This project form part of the EU Framework 6 Joint Research Activity on Smart Focal Planes. The instrument will offer multiobject spectroscopy, which will include the long slit mode, and image over a field of view of 1 to 2 arcmin, with high multiplexing capability. The use of a simple AO ground layer correction is envisaged but the instrument will not work at the diffraction limit though. Multi slits are the base line for the field selector, even when multi-IFU type instrument might be considered at later stage. There are two possible operational concepts for SMART-MOS, each of which involving different technologies: MOEMS type devices or sliding bars. We describe in this contribution the science cases and discuss the most relevant requirements which will drive the development. Preliminary optical and mechanical concepts are also sketched which include details about the most relevant part of the instrument.