The Gemini Infrared Multi-Object Spectrograph (GIRMOS) is a powerful new instrument being built to facility- class standards for the Gemini telescope. It takes advantage of the latest developments in adaptive optics and integral field spectrographs. GIRMOS will carry out simultaneous high-angular-resolution, spatially-resolved infrared (1 - 2.4 µm) spectroscopy of four objects within a two-arcminute field-of-regard by taking advantage of multi-object adaptive optics. This capability does not currently exist anywhere in the world and therefore offers significant scientific gains over a very broad range of topics in astronomical research. For example, current programs for high redshift galaxies are pushing the limits of what is possible with infrared spectroscopy at 8 -10- meter class facilities by requiring up to several nights of observing time per target. Therefore, the observation of multiple objects simultaneously with adaptive optics is absolutely necessary to make effective use of telescope time and obtain statistically significant samples for high redshift science. With an expected commissioning date of 2023, GIRMOS’s capabilities will also make it a key followup instrument for the James Webb Space Telescope when it is launched in 2021, as well as a true scientific and technical pathfinder for future Thirty Meter Telescope (TMT) multi-object spectroscopic instrumentation. In this paper, we will present an overview of this instrument’s capabilities and overall architecture. We also highlight how this instrument lays the ground work for a future TMT early-light instrument.
We present new results from the first search for transiting exoplanets undertaken from the High Arctic: the AWCam (Arctic Wide-field Cameras) survey. The survey, which has been operating for 2.5 years, is based at 80 degrees North on Ellesmere Island in the Canadian High Arctic. The small telescopes monitor 70,000 bright stars in a several-hundred square-degree region around Polaris, with milli-magnitude photometric precision, and are capable of discovering giant planets around 10,000 bright, nearby solar-type stars. We present the first longterm monitoring results from the AWCams, including an assessment of the site characteristics and the systems' long-term performance. The High-Arctic site provided excellent survey efficiency, without diurnal windowing and largely uninterrupted by clouds. Useful data was obtained over the entire survey field 71% of the time; the sky was clear 62% of the time. One pristine clear, dark period in winter 2012/13 persisted for 480 hours. In 2012/13 we recorded a period of 480 hours of continuous photometric conditions, attaining 3-4 millimag photometric stability over the entire period. We report the long-term photometric performance of the AWCam systems and detail the discovery of a bright (V=8) low-amplitude eclipsing binary. Finally, we present a concept for an extremely-wide-field arctic survey based on the Evryscope telescope-array design.
The Earth's polar regions offer unique advantages for ground-based astronomical observations with its cold and dry climate, long periods of darkness, and the potential for exquisite image quality. We present preliminary results from a site-testing campaign during nighttime from October to November 2012 at the Polar Environment Atmospheric Research Laboratory (PEARL), on a 610-m high ridge near the Eureka weatherstation on Ellesmere Island, Canada. A Shack-Hartmann wavefront sensor was employed, using the Slope Detection and Ranging (SloDAR) method. This instrument (Mieda et al, this conference) was designed to measure the altitude, strength and variability of atmospheric turbulence, in particular for operation under Arctic conditions. First SloDAR optical turbulence profiles above PEARL show roughly half of the optical turbulence confined to the boundary layer, below about 1 km, with the majority of the remainder in one or two thin layers between 2 km and 5 km, or above. The median seeing during this campaign was measured to be 0.65 arcsec.
Observations from near the Eureka station on Ellesmere Island, in the Canadian High Arctic at 80° North, benefit from 24-hour darkness combined with dark skies and long cloud-free periods during the winter. Our first astronomical surveys conducted at the site are aimed at transiting exoplanets; compared to mid-latitude sites, the continuous darkness during the Arctic winter greatly improves the survey’s detection effciency for longer-period transiting planets. We detail the design, construction, and testing of the first two instruments: a robotic telescope, and a set of very wide-field imaging cameras. The 0.5m Dunlap Institute Arctic Telescope has a 0.8-square-degree field of view and is designed to search for potentially habitable exoplanets around low-mass stars. The very wide field cameras have several-hundred-square-degree fields of view pointed at Polaris, are designed to search for transiting planets around bright stars, and were tested at the site in February 2012. Finally, we present a conceptual design for the Compound Arctic Telescope Survey (CATS), a multiplexed transient and transit search system which can produce a 10,000-square-degree snapshot image every few minutes throughout the Arctic winter.
The Cosmological Advanced Survey Telescope for Optical and UV Research (CASTOR) is a proposed CSA
mission that would make a unique, powerful, and lasting contribution to astrophysics by providing panoramic,
high-resolution imaging in the UV/optical (0.15 - 0.55 μm) spectral region. This versatile `smallSAT'-class
mission would far surpass any ground-based optical telescope in terms of angular resolution, and would provide
ultra-deep imaging in three broad lters to supplement longer-wavelength data from planned international dark
energy missions (Euclid, WFIRST) as well as from the ground-based Large Synoptic Survey Telescope (LSST).
Combining the largest focal plane ever
own in space, with an innovative optical design that delivers HST-quality
images over a eld two orders of magnitude larger than Hubble Space Telescope (HST), CASTOR would image
about 1/8th of the sky to a (u-band) depth ~1 magnitude fainter than will be possible with LSST even after a
decade of operations. No planned or proposed astronomical facility would exceed CASTOR in its potential for
discovery at these wavelengths.
Ground-layer adaptive optics (GLAO) has the potential to dramatically increase the efficiency and capabilities of
existing ground-based telescopes over a broad range of astronomical science. Recent studies of the optical turbulence
above several astronomical sites (e.g. Mauna Kea, Paranal, and Antarctica) show that GLAO can be extended to fields of
view of several tens of arcminutes in diameter, larger than previously thought, with angular resolutions close to the freeatmosphere
seeing. This is a pivotal result since GLAO science cases benefit from the largest possible corrected fields
of view. The corrected areal field of a GLAO system is potentially 2-3 orders of magnitude larger than has been
demonstrated to date. The 'Imaka team is working toward an instrument that takes advantage of the one-degree field
afforded by Mauna Kea. In this paper we summarize the design/simulation work to date along with our plan to develop
an instrument that reaches for this wide field of view.
As part of a program to measure and evaluate atmospheric turbulence on mountains at the most northerly tip of North
America, we have deployed two SODARs and a lunar scintillometer at the Polar Environment Atmospheric Research
Lab (PEARL) located on a 600m-high ridge near Eureka on Ellesmere Island, at 80° latitude. This paper discusses the
program and presents a summary of ground-layer turbulence and seeing measurements from the 2009-10 observing
We present the results of the design studies of the science calibration system for the adaptive optics and infrared
instruments of the Thirty Meter Telescope. The two major requirements of the science calibration system are to provide
pupil-simulated telescope beams to the adaptive optics system for calibration of the telescope pupil and to provide flatfielding
and wavelength-calibration illuminations to client instruments of the adaptive optics system. Our current system
is composed an integrating sphere with calibration light sources, a retractable pupil-mask system, a lens assembly
consisting of a pair of achromatic triplets, and fold mirrors. This system appears to be capable of producing highlyuniform
of f/15 beams at the telescope focal plane and pupil simulation at a pupil location within the adaptive optics
system. We describe the present design and development of the calibration system along with relevant analyses.
The 'Imaka project is a high-resolution wide-field imager proposed for the Canada-France-Hawaii telescope
(CFHT) on Mauna Kea. 'Imaka takes advantage of two features of the optical turbulence above Mauna Kea:
weak optical turbulence in the free-atmosphere and boundary layer turbulence which is highly confined within a
surface layer tens of meters thick and or the telescope enclosures. The combination of the two allows a groundlayer
adaptive optics system (GLAO) to routinely deliver an extremely-wide corrected field of view of one-degree
at an excellent free-atmosphere seeing limit at visible wavelengths. In addition, populating the focal-plane with
orthogonal-transfer CCDs provides a second level of image improvement on the free-atmosphere seeing and the
residual GLAO correction. The impact of such an instrument covers a broad range of science and is a natural
progression of CFHT's wide-field expertise.
We present the scientific motivations for GYES: a high multiplex (of the order of several hundred), high resolution
(about 20 000), spectrograph to be placed at the prime focus of the CFHT. The main purpose of such an
instrument is to conduct a spectroscopic survey complementary to the Gaia mission. The final Gaia catalogue
(expected around 2020) will provide accurate distances, proper motions and spectrophotometry for all the stars
down to a magnitude of 20. The spectroscopic instrument on board the Gaia satellite will provide intermediate
resolution (R=11 500) spectra for stars down to the 17th magnitude. For the fainter stars there will be no radial
velocity information. For all the stars the chemical information will be limited to a few species. A multifibre
spectrograph at the prime focus of the CFHT will be able to provide the high resolution spectra for stars fainter
than 13th magnitude, needed to obtain both accurate radial velocities and detailed chemical abundances. The possible use of GYES will not be limited to Gaia complementary surveys and we here describe the potentialities
of such an instrument. We describe here how the scientific drivers are translated into technical requirements.
The results of our on-going feasibility study are described in an accompanying poster.
The goal of this project is to achieve exquisite image quality over the largest possible field of view, with a goal of a
FWHM of not more than 0.3" over a square degree field in the optical domain. The narrow PSF will allow detection of
fainter sources in reasonable exposure times. The characteristics of the turbulence of Mauna Kea, a very thin ground
layer with excellent free seeing allows very wide fields to be corrected by GLAO and would make such an instrument
unique. The Ground Layer AO module uses a deformable mirror conjugated to the telescope pupil. Coupled with a high
order WFS, it corrects the turbulence common to the entire field. Over such large fields the probability of finding
sufficiently numerous and bright natural guide sources is high, but a constellation of laser beacons could be considered
to ensure homogeneous and uniform image quality.
The free atmosphere seeing then limits the image quality (50% best conditions: 0.2" to 0.4"). This can be further
improved by an OTCCD camera, which can correct local image motion on isokinetic scales from residual high altitude
tip-tilt. The advantages of the OTCCD are not limited to improving the image quality: a Panstarrs1 clone covers one
square degree with 0.1" sampling, in perfect accordance with the scientific requirements. The fast read time (6 seconds
for 1.4 Gpixels) also leads to an improvement of the dynamic range of the images. Finally, the guiding capabilities of
the OTCCD will provide the overall (local and global) tip-tilt signal.
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
The elegant theory that underlies gravitational lensing phenomena makes it a powerful tool for exploring the large scale structure of the universe. ELTs bring improved angular resolution and faint source spectroscopy capabilities to gravitational lensing studies which will enble qualitatively new investigations. Probing background sources having more than a decade higher source density than current studies will take weak lensing measurements from the outskirts of individual clusters into the cosmic web. These measurements require imaging and spectroscopy of distant galaxies fainter than mAB ~ 27 mag (~50 nano-Jansky). Strong gravitational lensing magnifies background sources and will allow the study of individual unresolved sources at least one decade fainter in flux than the telescope will otherwise reach, providing exploratory studies for 100m class telescopes. Strongly lensed sources will allow spectroscopy at sub nano-Jansky source frame flux levels in about 106 seconds. The expected sources include globular clusters in formation and individual first light stars. The geometry of strong lensing will also become a powerful constraint on cosmological constants. In lensed sources it will be possible to measure source frame velocities at about the 500 km s-1 level. These science goals will require an AO capability in which the PSF shape can be mapped to a precision of 1-2% over a field of about 2 arc-minutes, an integral field-unit spectrograph capable of being deployed on arcs that are generally 10 arc-seconds long and astrometric precision at the level of 10's of micro arc-second.
A design is proposed for a 20 m Canadian Very Large Optical Telescope (VLOT). This design meets the science, schedule, and availability requirements of the Canadian astronomical community. The telescope could be operational by early in the next decade to complement the science discoveries of the Next Generation Space Telescope (NGST) and Atacama Large Millimeter Array (ALMA). This design is suitable for location on the Mauna Kea summit ridge, and could replace the current 3.6 m CFHT telescope. The telescope structure provides room for two vertically oriented Nasmyth instruments, implements a very stiff monocoque mirror cell, and offers a short and direct load path to the telescope mount. A Calotte style dome structure offers many advantages over current designs including lower and more even power requirements, and a circular aperture that will better protect the telescope structure from wind buffeting. The science requirements are presented, and the telescope optical design, primary mirror pupil segmentation options, including hexagonal segments and a radial segment design with a central 8 m mirror, are considered. Point spread function plots and encircled energy calculations show that there is no significant diffraction performance difference between the options except that hexagonal segments in the 1 m point-to-point range appear to deliver poorer PSF's as compared to 2 m and larger segments. Plans for implementation of a Matlab based integrated telescope model are discussed. A summary of adaptive optics system issues for large telescopes is presented along with plans for future research in AO.