We report on the design, on-sky performance, and status of the FLAMINGOS-2 instrument – the fully-cryogenic facility
near-infrared imager and multi-object spectrograph for the Gemini 8-meter telescopes. FLAMINGOS-2 has a refractive
all-spherical optical system providing 0.18-arcsecond pixels and a 6.2-arcminute circular field-of-view on a 2048x2048-
pixel HAWAII-2 0.9-2.4 μm detector array. A slit/decker wheel mechanism allows the selection of up to 9 multi-object
laser-machined plates or 3 long slits for spectroscopy over a 6x2-arcminute field of view, and selectable grisms provide
resolutions from ~1300 to ~3000 over the entire spectrograph bandpass. FLAMINGOS-2 is also compatible with the
Gemini Multi-Conjugate Adaptive Optics system, providing multi-object spectroscopic capabilities over a 3x1-arcminute
field with high spatial resolution (0.09-arcsec/pixel). We review the designs of optical, mechanical, electronics,
software, and On-Instrument WaveFront Sensor subsystems. We also present the on-sky performance measured during
acceptance testing in 2009, as well as current status of the project and future plans.
Mountains along the northwestern coast of Ellesmere Island, Canada, possess the highest peaks nearest the Pole. This
geography, combined with an atmospheric thermal inversion restricted to below ~1000 m during much of the long arctic
night, provides excellent opportunities for uninterrupted cloud-free astronomy - provided the challenges of these
incredibly remote locations can be overcome. We present a miniaturized robotic observatory for deployment on a High
Arctic mountaintop. This system tested the operability of precise optical instruments during winter, and the logistics of
installation and maintenance during summer. It is called Ukpik after the Inuktitut name for the snowy owl, and was
deployed at two sites accessible only by helicopter, each north of 82 degrees latitude; one on rock at 1100 m elevation
and another on a glacier at 1600 m. The instrument suite included at first an all-sky-viewing camera, with the later
addition of a small telescope to monitor Polaris, both protected by a retractable weather-proof enclosure. Expanding this
to include a narrow-field drift-scanning camera for studying extra-solar planet transits was also investigated, but not
implemented. An unique restriction was that all had to be run on batteries recharged primarily by a wind turbine.
Supplementary power came from a methanol fuel-cell electrical generator. Communications were via the Iridium
satellite network. The system design, and lessons learned from three years of operation are discussed, along with
prospects for time-domain astronomy from isolated, high-elevation polar mountaintops.
S. Claude, F. Jiang, P. Niranjanan, P. Dindo, D. Erickson, K. Yeung, D. Derdall, D. Duncan, D. Garcia, B. Leckie, M. Pfleger, G. Rodrigues, K. Szeto, P. Welle, I. Wood, K. Caputa, A. Lichtenberger, S-K. Pan
The Band 3 receiver, covering the 84-116 GHz frequency band is one of the 10 channels that will be installed on the
Atacama Large Millimeter Array (ALMA). A total of 73 units have to be built in two phases: 8 preproduction and then
65 production units. This paper reports on the assembly, testing and performance of the preproduction series of these
state-of-the-art millimeter receivers.
Coastal mountains at Canada's northern tip possess many of the desirable properties that make the Antarctic glacial
plateau attractive for astronomy: they are cold, high, dry, and in continuous darkness for several months in winter.
Satellite images suggest that they should also benefit from clear skies for a fraction of time comparable to the best mid-latitude
sites, and conventional site-selection criteria point to good seeing. In order to confirm these conditions, we are
testing three mountain sites on northwestern Ellesmere Island, in Nunavut. On each we have installed a compact,
autonomous site-testing station consisting of a meteorological station, a simple optical/near-infrared camera for sensing
cloud cover, and - at one site - a more advanced all-sky viewing camera. The systems were deployed by helicopter and
run on batteries recharged by wind (a compact methanol fuel cell is under study as a supplementary power source).
Effective two-way communications via the Iridium satellite network allows a limited number of highly compressed
images to be transferred. The full-winter dataset is stored at the site on flash-drives, thus requiring a return visit to
retrieve, but day-to-day station performance can be assessed using telemetry and a computer model. Based on site-testing
results, the plan is to select one site for the addition of a seeing monitor and a small but scientifically productive
telescope.
We report on the design and status of the FLAMINGOS-2 instrument - a fully-cryogenic facility near-infrared imager
and multi-object spectrograph for the Gemini 8-meter telescopes. FLAMINGOS-2 has a refractive all-spherical optical
system providing 0.18-arcsecond pixels and a 6.2-arcminute circular field-of-view on a 2048×2048-pixel HAWAII-2
0.9-2.4 μm detector array. A slit/decker wheel mechanism allows the selection of up to 9 multi-object laser-machined
plates or 3 long slits for spectroscopy over a 6×2-arcminute field of view, and selectable grisms provide resolutions from
~1300 to ~3000 over the entire spectrograph bandpass. FLAMINGOS-2 is also compatible with the Gemini Multi-
Conjugate Adaptive Optics system, providing multi-object spectroscopic capabilities over a 3×1-arcminute field with
high spatial resolution (0.09-arcsec/pixel). We review the designs of optical, mechanical, electronics, software, and On-
Instrument WaveFront Sensor subsystems. We also present the current status of the project and future plans, including
on-sky delivery planned for late 2008.
Atmospheric turbulence compensation via adaptive optics (AO) will be essential for achieving most objectives of the
TMT science case. The performance requirements for the initial implementation of the observatory's facility AO system
include diffraction-limited performance in the near IR with 50 per cent sky coverage at the galactic pole. This capability
will be achieved via an order 60x60 multi-conjugate AO system (NFIRAOS) with two deformable mirrors optically
conjugate to ranges of 0 and 12 km, six high-order wavefront sensors observing laser guide stars in the mesospheric
sodium layer, and up to three low-order, IR, natural guide star wavefront sensors located within each client instrument.
The associated laser guide star facility (LGSF) will consist of 3 50W class, solid state, sum frequency lasers,
conventional beam transport optics, and a launch telescope located behind the TMT secondary mirror.
In this paper, we report on the progress made in designing, modeling, and validating these systems and their components
over the last two years. This includes work on the overall layout and detailed opto-mechanical designs of NFIRAOS and
the LGSF; reliable wavefront sensing methods for use with elongated and time-varying sodium laser guide stars;
developing and validating a robust tip/tilt control architecture and its components; computationally efficient algorithms
for very high order wavefront control; detailed AO system modeling and performance optimization incorporating all of
these effects; and a range of supporting lab/field tests and component prototyping activities at TMT partners. Further
details may be found in the additional papers on each of the above topics.
The near-Infrared Multi-Object Spectrograph (IRMOS) for TMT is one of the most powerful astronomical instruments ever envisioned. The combination of the collecting area of TMT, the unique image-sharpening capabilities of the Multi-Object Adaptive Optics (MOAO) system, and the multiplexing advantage of the multi-object integral-field spectra provided by the IRMOS back-end make it capable of addressing some of the leading scientific challenges of the coming decades. Here we present an overview of one potential IRMOS concept and then focus on the MOAO system. In particular we will describe our concept for the laser and natural guide star wavefront sensors, deformable mirrors and the calibration system of MOAO. For each of these design elements, we describe the key trade studies which help define each subsystem. From results of our studies, we assemble a MOAO ensquared energy budget. We find that 50% of the energy is ensquared within the 50 milli-arcsecond spatial pixel of the IRMOS integral field units for a wavelength of 1.65μm. Given the requirements placed on the MOAO system to achieve this performance, large ensquared energies can be achieved with even finer plate scales for wavelengths longer than 1.5μm.
An On-Instrument Wavefront Sensor (OIWFS) designed, built and tested by the National Research Council of Canada (NRC) for the FLoridA Multi-object Imaging Near-IR Grism Observational Spectrometer (FLAMINGOS) is described. The University of Florida is building the FLAMINGOS-2 IR spectrograph for the Gemini Observatory as a near copy of the original multi-telescope FLAMINGOS instrument. NRC/HIA was subcontracted to build the OIWFS based on the Gemini Multi-Object Spectrograph (GMOS) design.
The FLAMINGOS-2 OIWFS patrols the bulk of the FLAMINGOS-2 field-of-view and will accept the Gemini f/16 input beam as well as the f/30 beam from the Gemini Multi-Conjugate Adaptive Optics (MCAO) system. The portion of the probe arm that enters the FLAMINGOS-2 field-of-view is cooled, to avoid contaminating the infrared images. The OIWFS uses the same CCD and CCD controller as was used on GMOS (e2v CCD39 and ARC GENII). Mechanically, the OIWFS is a modified version of the GMOS OIWFS. It comprises two stacked rotational stages, each operating on a single bearing. The top stage supports an optics package, which includes a lenslet array, pickoff arm and CCD. The optical design uses a four subaperture Shack-Hartmann lenslet array. The mechanism is controlled using EPICS based software that includes GUI engineering screens.
Test results showing the OIWFS to be fully compliant with design specifications are presented.
We report on the design and status of the FLAMINGOS-2 instrument - a fully-cryogenic facility near-infrared imager
and multi-object spectrograph for the Gemini 8-meter telescopes. FLAMINGOS-2 has a refractive all-spherical optical
system providing 0.18-arcsecond pixels and a 6.2-arcminute circular field-of-view on a 2048×2048-pixel HAWAII-2
0.9-2.4 μm detector array. A slit/decker wheel mechanism allows the selection of up to 9 multi-object laser-machined
plates or 3 long slits for spectroscopy over a 6×2-arcminute field of view, and selectable grisms provide resolutions from
~1300 to ~3000 over the entire spectrograph bandpass. FLAMINGOS-2 is also compatible with the Gemini Multi-
Conjugate Adaptive Optics system, providing multi-object spectroscopic capabilities over a 3×1-arcminute field with
high spatial resolution (0.09-arcsec/pixel). We review the designs of optical, mechanical, electronics, software, and On-
Instrument WaveFront Sensor subsystems. We also present the current status of the project, currently in final testing in
mid-2006.
We present an overview of the near-InfraRed Multi-Object Spectrograph (IRMOS) for the Thirty Meter Telescope, as developed under a Feasibility Study at the University of Florida and Herzberg Institute of Astrophysics. IRMOS incorporates a multi-object adaptive optics correction capability over a 5-arcminute field of regard on TMT. Up to 20 independently-selectable target fields-of-view with ~2-arcsec diameter can be accessed within this field simultaneously. IRMOS provides near-diffraction-limited integral field spectroscopy over the 0.8-2.5 μm bandpass at R~1,000-20,000 for each target field. We give a brief summary of the Design Reference science cases for IRMOS. We then present an overview of the IRMOS baseline instrument design.
We report on the design and status of the FLAMINGOS-2 instrument - a fully-cryogenic facility near-infrared imager and multi-object spectrograph for the Gemini 8-meter telescopes. FLAMINGOS-2 has a refractive all-spherical optical system providing 0.18-arcsecond pixels and a 6.2-arcminute circular field-of-view on a 2048x2048-pixel HAWAII-2 0.9-2.4 mm detector array. A slit/Dekker wheel mechanism allows the selection of up to 9 multi-object laser-machined plates or 3 long slits for spectroscopy over a 6x2-arcminute field of view, and selectable grisms provide resolutions from ~1300 to ~3000 over the entire spectrograph bandpass. FLAMINGOS-2 is also compatible with the Gemini Multi-Conjugate Adaptive Optics system, providing multi-object spectroscopic capabilities over a 3x1-arcminute field with high spatial resolution (0.09-arcsec/pixel). We review the designs of optical, mechanical, electronics, software, and On-Instrument WaveFront Sensor subsystems. We also present the current status of the project, midway through its construction phase in June 2004.
The first of two Gemini Multi Object Spectrographs (GMOS) has recently begun operation at the Gemini-North 8m telescope. In this presentation we give an overview of the instrument and describe the overall performance of GMOS-North both in the laboratory during integration, and at the telescope during commissioning. We describe the development process which led to meeting the demanding reliability and performance requirements on flexure, throughput and image quality. We then show examples of GMOS data and performance on the telescope in its imaging, long-slit and MOS modes. We also briefly highlight novel features in GMOS that are described in more detail in separate presentations, particularly the flexure compensation system and the on-instrument wavefront sensor. Finally we give an update of the current status of GMOS on Gemini-North and future plans.
The Gemini Adaptive Optics System, (Altair), under construction at the National Research Council of Canada's Herzberg Institute of Astrophysics is unique among AO systems. Altair is designed with its deformable mirror (DM) conjugate to high altitude. We summarize construction progress. We then describe Altair in more detail. Both the Wavefront sensor foreoptics and control system are unconventional, because the guide star footprint on an altitude-conjugated DM moves as the guide star position varies. During a typical nodding sequence, where the telescope moves 10 arcseconds between exposures, this footprint moves by half an actuator and/or WFS lenslet. The advantages of altitude conjugation include increased isoplanatic patch size, which improves sky coverage, and improved uniformity of the corrected field. Altitude conjugation also reduces focal anisoplanatism with laser beacons. Although the initial installation of Altair will use natural guide stars, it will be fully ready to use a laser guide star (LGS). The infrastructure of Gemini observatory provides a variety of wavefront sensors and nested control loops that together permit some unique design concepts for Altair.
As the only two optical instruments appearing in its first fleet of instrumentation, the GEMINI MultiObject Spectrograph (GMOS) are indeed being developed as workhorse instruments. One GMOS will be located at each of the GEMINI telescopes to perform: (1) exquisite direct imaging, (2) 5.5 arcminute longslit spectroscopy, (3) up to 600 object multislit spectroscopy, and (4) about 2000 element integral field spectroscopy. The GMOSs are the only GEMINI instrumentation duplicated at both telescopes. The UK and Canadian GMOS team successfully completed their critical design review in February 1997. They are now well into the fabrication phase, and will soon approach integration of the first instrument. The first GMOS is scheduled to be delivered to Mauna Kea in the fall of '99 and the second to Cerro Pachon one year later. In this paper, we will look at how a few of the more interesting details of the final GMOS design help meet its demanding scientific requirements. These include its transmissive optical design and mask handling mechanisms. We will also discuss our plans for the mask handling process in GEMINI's queue scheduled environment, from the taking of direct images through to the use of masks on the telescope. Finally, we present the status of fabrication and integration work to date.
The Gemini telescopes implement active optics and atmospheric tip-tilt-focus correction through the use of a number of Shack-Hartmann wavefront sensors at several locations and providing various orders of wavefront data. All are based on a common Charge Coupled Device (CCD) housing and controller. This paper provides an overview of the electronics in the CCD head and controller. The two frame-transfer CCDs that are used (80 X 80 and 1024 X 1024), are described. A parameter based multiple subaperture readout algorithm is presented. The system is capable of operating at 2000 frames per second in a 2 X 2 subaperture mode with 36 pixels per subaperture and a read-noise floor of approximately 4.5 erms.
The two Gemini multiple object spectrographs (GMOS) are being designed and built for use with the Gemini telescopes on Mauna Kea and Cerro Pachon starting in 1999 and 2000 respectively. They have four operating modes: imaging, long slit spectroscopy, aperture plate multiple object spectroscopy and area (or integral field) spectroscopy. The spectrograph uses refracting optics for both the collimator and camera and uses grating dispersion. The image quality delivered to the spectrograph is anticipated to be excellent and the design is driven by the need to retain this acuity over a large wavelength range and the full 5.5 arcminute field of view. The spectrograph optics are required to perform from 0.36 to 1.8 microns although it is likely that the northern and southern versions of GMOS will use coatings optimized for the red and blue respectively. A stringent flexure specification is imposed by the scientific requirement to measure velocities to high precision (1 - 2 km/s). Here we present an overview of the design concentrating on the optical and mechanical aspects.
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