OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) was the optical Day One instrument
for the 10.4m Spanish telescope GTC. It is installed at the Observatorio del Roque de Los Muchachos (La Palma, Spain).
This instrument has been operational since March-2009 and covers from 360 to 1000 nm. OSIRIS observing modes
include direct imaging with tunable and conventional filters, long slit and low resolution spectroscopy. OSIRIS wide
field of view and high efficiency provide a powerful tool for the scientific exploitation of GTC. OSIRIS was developed
by a Consortium formed by the Instituto de Astrofísica de Canarias (IAC) and the Instituto de Astronomía de la
Universidad Nacional Autónoma de México (IA-UNAM). The latter was in charge of the optical design, the manufacture
of the camera and collaboration in the assembly, integration and verification process. The IAC was responsible for the
remaining design of the instrument and it was the project leader. The present paper considers the development of the
instrument from its design to its present situation in which is in used by the scientific community.
LIRIS is a near-infrared intermediate resolution spectrograph with added capabilities for multi-slit, imaging, coronography, and polarimetry, developed by the Instituto de Astrofisica de Canarias (IAC). It will be a common user instrument for the Cassegrain focus of the William Herschel Telescope (WHT) at the Roque de los Muchachos Observatory in La Palma. At its first commissioning, that was held in February 2003, the functionality of the mechanisms (entrance wheel, central wheels and camera wheel) under variable orientation of the telescope was verified, and no thermal nor structural problems arose. The functionality of the mechanical interface with telescope (allows for up to 5 mm of lateral displacements in the attachment plane), of the LIRIS handling trolley, of the transport equipment and of all the equipments used in the integration was also checked. For the second commissioning of LIRIS, which has been held in March 2004, some modifications have been done. The results of both commissionings were satisfactory.
LIRIS is a near-infrared (1-2.5 microns) intermediate resolution spectrograph (R=1000-3000) with added capabilities for multi-slit, imaging, coronography, and polarimetry, built by the IAC to be a common instrument for the WHT (La Palma). Here we report the results of the two commissioning periods. The image quality was checked, obtaining a FWHM of 0".5 in the Ks band over the whole field of view (4'.2 x 4'.2). Zero points and sky brightness were measured, and very low values were found in the latter. The long slit spectra obtained matched the expected spectral resolution (2.6 pixels for a 0".65-wide slit). Flexure tests were carried out with good results. Several science targets were observed, the most note-worthy result being the detection of the CIV 154.9 nm line in the most distant qso at z=6.41.
OSIRIS (Optical System for Imaging and low/intermediate-Resolution Integrated Spectroscopy) is an instrument designed to obtain images and low resolution spectra of astronomical objects in the optical domain (from 365 through 1000nm). It will be installed on Day One in the Nasmyth focus of the 10-meter Spanish GTC Telescope, although it shall be possible to install it in the Cassegrain focus as well. It is expected to be in operation at the end of 2003.
The Slit Unit is an automated slit mask loader based in cam followers technology, being designed at the IAC for the OSIRIS Spectrograph. It provides a store with space for as many as 13 multislits mask and long slit mask for an unvignetted field of view of 8.53'x8.67', available at the same time for observing purposes. A two-degrees-of-freedom mechanism allows to select one of the masks, to remove it from the cassette and to position it in the focal plane with the required repeatability. The complete design of the mechanism is presented, including an analysis of the predicted performances and a 3-D model used to check the geometry and mass properties.
OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) is the optical Day One instrument for the 10.4m Spanish telescope GTC to be installed in the Observatorio del Roque de Los Muchachos (La Palma, Spain). This instrument, operational in mid-2004, covers from 360 up to 1000 nm. OSIRIS observing modes include direct imaging with tunable and conventional filters, long slit and multiple object spectroscopy and fast spectrophotometry. The OSIRIS wide field of view, high efficiency and the new observing modes (tunable imaging and fast spectrophotometry) for 8-10m class telescopes will provide GTC with a powerful tool for their scientific exploitation. The present paper provides an updated overview of the instrument development, of some of the scientific projects that will be tackled with OSIRIS and of the general requirements driving the optical and mechanical design.
The Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS) will be a Day-One instrument of the Spanish 10.4 m telescope Gran Telescopio Canarias, whose first light is planned for 2002. GTC will be installed at the Observatorio del Roque de los Muchachos in La Palma, Spain. OSIRIS three primary modes are imaging and low resolution long slit and multiple object spectroscopy. The instrument is designed to operate from 365 to 1000 nm with a field of view of 7 by 7 arcminutes and a maximum spectral resolution of 5000. Among the OSIRIS main features are the use of tunable filters for direct imaging, the use of Volume Phase Holographic Gratings as dispersive elements for spectroscopy, and the implementation of an articulated camera to provide maximum spectroscopic efficiency and versatility. Here we present a general description and an overview of the main instrument characteristics.