Philippe Vallee

TRIDENT: An Infrared Differential Imaging Camera Optimized for the Detection of Methanated Substellar Companions

ABSTRACT We describe a near‐infrared camera in use at the Canada‐France‐Hawaii Telescope (CFHT) and at the 1.6 m telescope of the Observatoire du mont Megantic (OMM). The camera is based on a Hawaii‐1 1024 × 1024 HgCdTe array detector. Its main feature is the acquisition of three simultaneous images at three wavelengths across the methane absorption bandhead at 1.6 μm, enabling, in theory, an accurate subtraction of the stellar point‐spread function (PSF) and the detection of faint close, methanated companions. The instrument has no coronagraph and features fast data acquisition, yielding high observing efficiency on bright stars. The performance of the instrument is described, and it is illustrated by laboratory tests and CFHT observations of the nearby stars GL 526, υ And, and χ And. TRIDENT can detect (6 σ) a methanated companion with \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \use...

SPIRou: the near-infrared spectropolarimeter/high-precision velocimeter for the Canada-France-Hawaii telescope

SPIRou is a near-IR echelle spectropolarimeter and high-precision velocimeter under construction as a next- generation instrument for the Canada-France-Hawaii-Telescope. It is designed to cover a very wide simultaneous near-IR spectral range (0.98-2.35 μm) at a resolving power of 73.5K, providing unpolarized and polarized spectra of low-mass stars at a radial velocity (RV) precision of 1m/s. The main science goals of SPIRou are the detection of habitable super-Earths around low-mass stars and the study of stellar magnetism of star at the early stages of their formation. Following a successful final design review in Spring 2014, SPIRou is now under construction and is scheduled to see first light in late 2017. We present an overview of key aspects of SPIRou’s optical and mechanical design.

The integral field spectrograph for the Gemini planet imager

The Gemini Planet Imager (GPI) is a complex optical system designed to directly detect the self-emission of young planets within two arcseconds of their host stars. After suppressing the starlight with an advanced AO system and apodized coronagraph, the dominant residual contamination in the focal plane are speckles from the atmosphere and optical surfaces. Since speckles are diffractive in nature their positions in the field are strongly wavelength dependent, while an actual companion planet will remain at fixed separation. By comparing multiple images at different wavelengths taken simultaneously, we can freeze the speckle pattern and extract the planet light adding an order of magnitude of contrast. To achieve a bandpass of 20%, sufficient to perform speckle suppression, and to observe the entire two arcsecond field of view at diffraction limited sampling, we designed and built an integral field spectrograph with extremely low wavefront error and almost no chromatic aberration. The spectrograph is fully cryogenic and operates in the wavelength range 1 to 2.4 microns with five selectable filters. A prism is used to produce a spectral resolution of 45 in the primary detection band and maintain high throughput. Based on the OSIRIS spectrograph at Keck, we selected to use a lenslet-based spectrograph to achieve an rms wavefront error of approximately 25 nm. Over 36,000 spectra are taken simultaneously and reassembled into image cubes that have roughly 192x192 spatial elements and contain between 11 and 20 spectral channels. The primary dispersion prism can be replaced with a Wollaston prism for dual polarization measurements. The spectrograph also has a pupil-viewing mode for alignment and calibration.

GriF: The New Three‐dimensional Spectroscopic Mode of PUEO, the Canada‐France‐Hawaii Telescope Adaptive Optics Bonnette: First Observations in the Fabry‐Pérot Scanning Mode

ABSTRACT Three‐dimensional spectroscopy has the advantage of providing (quasi‐) simultaneously both spatial and spectral information. Coupled to adaptive optics, it conjugates spectroscopic power with high angular resolution. GriF offers these capabilities in the near‐infrared. As a new observing mode of KIR, the camera behind PUEO, the Canada‐France‐Hawaii Telescope adaptive optics bonnette, it provides images at the diffraction limit of the telescope in the K band. Spectroscopy at a resolution of 2000 is provided by a Fabry‐Perot interferometer coupled with a grism, cooled to limit the background. This setup offers a large multiplex gain by observing simultaneously up to five monochromatic images. This article first describes the instrument and the calibration procedures. Next, we demonstrate GriF performances from its first observations, obtained on the Orion molecular cloud OMC‐1.

KIR: the high-spatial-resolution 1024 x 1024 near-infrared camera of the Canada-France-Hawaii Telescope

KIR is a 1024 by 1024 near-IR camera used with the adaptive optics Bonnette (PUEO) of the Canada-France-Hawaii Telescope. The camera houses a 1024 by 1024 HgCdTe and simple refractive optics providing diffraction-limited images with an image scale of 0.035 inch/pixel. First light was obtained in December 1997. The throughput of the camera, from the top of the atmosphere down to the atmosphere down to the detector including PUEO, is 19 percent, 20 percent and 21 percent at J, H and K, respectively. This project is a collaboration between the Universite de Montreal, the Observatoire Midi Pyrenees and the Canada-France-Hawaii Telescope. The design and performance of the instrument are presented in this paper.

CPAPIR: a wide-field infrared camera for the Observatoire du Mont Mégantic

CPAPIR is a wide-field infrared camera for use at the Observatoire du mont Megantic and CTIO 1.5 m telescopes. The camera will be primarily a survey instrument with a half-degree field of view, making it one of the most efficient of its kind. CPAPIR will provide broad and narrow band filters within its 0.8 to 2.5 μm bandpass. The camera is based on a Hawaii-2 2048x2048 HgCdTe detector.

SPIRou @ CFHT: spectrograph optical design

SPIRou is a near-infrared, echelle spectropolarimeter/velocimeter under design for the 3.6m Canada-France-Hawaii Telescope (CFHT) on Mauna Kea, Hawaii. The unique scientific capabilities and technical design features are described in the accompanying (eight) papers at this conference. In this paper we focus on the lens design of the optical spectrograph. The SPIROU spectrograph is a near infrared fiber fed double pass cross dispersed spectrograph. The cryogenic spectrograph is connected with the Cassegrain unit by the two science fibers. It is also fed by the fiber coming from the calibration box and RV reference module of the instrument. It includes 2 off-axis parabolas (1 in double pass), an echelle grating, a train of cross disperser prisms (in double pass), a flat folding mirror, a refractive camera and a detector. This paper describes the optical design of the spectrograph unit and estimates the performances. In particular, the echelle grating options are discussed as the goal grating is not available from the market.

SPIRou @ CFHT: design of the instrument control system

SPIRou is a near-IR (0.98-2.35μm), echelle spectropolarimeter / high precision velocimeter being designed as a nextgeneration instrument for the 3.6m Canada-France-Hawaii Telescope on Mauna Kea, Hawaii, with the main goals of detecting Earth-like planets around low-mass stars and magnetic fields of forming stars. The unique scientific and technical capabilities of SPIRou are described in a series of eight companion papers. In this paper, the means of controlling the instrument are discussed. Most of the instrument control is fairly normal, using off-the-shelf components where possible and reusing already available code for these components. Some aspects, however, are more challenging. In particular, the paper will focus on the challenges of doing fast (50 Hz) guiding with 30 mas repeatability using the object being observed as a reference and on thermally stabilizing a large optical bench to a very high precision (~1 mK).μ

Development of a 4k×4k frame transfer electron multiplying CCD for scientific applications

The CCD282 is a large low-light level (L3 - Electron multiplying CCD) imaging sensor developed by e2v technologies for the University of Montreal. The intended use is for photon counting and very low light level imaging. The device will be used on the 3DNTT instrument which is a scanning Fabry-Perot interferometer. There is also the intention to place a device on a 10m class telescope for scanning Fabry-Perot application. This sensor is the largest electron multiplying CCD device produced to date with a 4k×4k backside illuminated frame transfer architecture. The sensor uses 8 parallel EM (Electron Multiplying) amplified outputs to maximize throughput. This paper present the first results and performance measurements of this device, and especially of the clock induced charge (CIC) which is one order of magnitude lower than previous devices thanks to a specific design optimized for photon counting operation.

GPI: cryogenic spectrograph optics performances

The science instrument for GPI (Gemini Planet Imager) is a cryogenic integral field spectrograph based on a lenslet array. The integral field nature of the instrument allows for a full mapping of the focal plane at coarse spectral resolution. With such a data cube, artifacts within the PSF such as residual speckles can be suppressed. Additionally, the initial detection of any candidate planet will include spectral information that can be used to distinguish it from a background object: candidates can be followed up with detailed spectroscopic observations. The optics between the lenslet array and the detector are essentially a standard spectrograph with a collimating set of lenses, a dispersive prism and a camera set of lenses in a folded assembly. We generally refer to this optical set as the spectrograph optics. This paper describes the laboratory optical performances over the field of view. The test procedure includes the imaging performances in both non dispersive and dispersive mode. The test support equipments include a test cryostat, an illumination module with monochromatic fiber laser, a wideband light source and a test detector module.