The Maunakea Spectroscopic Explorer Book 2018

(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSE's science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.Comment: 5 chapters, 160 pages, 107 figure

Des spectro-imageurs de nouvelle génération - Scruter le Soleil avec GOLF-NG

Voilà quatre siècles au moins que le Soleil manifeste une activité fortement variable montrant, de manière récurrente, des taches sombres à sa surface. Les incidences de cette variabilité sur l’atmosphère terrestre restent encore mal comprises des chercheurs malgré des corrélations surprenantes avec le climat du passé. L’invention de techniques innovantes permettra seule de maîtriser les processus générant cette variabilité et de prédire l’activité solaire du prochain siècle

Exposure System and Dosimetry for in vitro Studies of Biocompatibility of Pulse-Modulated RF Signals of Ultra High Field MRI.

International audience: A new set-up for exposure of human cells in vitro at 37°C to pulse-modulated 300 MHz and 500 MHz signals of future magnetic resonance imaging (MRI) systems is designed, built up, and characterized. Two dipole antennas, specifically designed for ultra high field MRI, are used as radiating structures. The electromagnetic (EM) field distribution inside the incubator containing the cells is computed, and it is shown to be in a good agreement with measurements. The electric field at the cell level is quantified numerically. Local, 1g average, and averaged over the culture medium volume SAR are provided along with the standard deviation values for each well. Temperature increments are measured inside the culture medium during the exposure using an optical fiber thermometer. Then we identify the pulse parameters corresponding to the thermal threshold of 1°C, usually considered as a threshold for thermally-induced biological effects. For these parameters, the induction of heat shock proteins is assessed to biologically verify a potential thermal response of cells. The data demonstrate that, under the considered experimental conditions, exposure to pulsemodulated radiations emulating typical ultra high field MRI signals, corresponding to temperature increments below 1°C, does not trigger any heat shock response in human brain cells

Maunakea Spectroscopic Explorer Low Moderate Resolution Spectrograph: paths toward the Preliminary Design Phase

International audienceThe Maunakea Spectroscopic Explorer (MSE) is a 10m-class, wide-field (1.5 sq. degree) and high-multiplex (< 3000 fibers) spectroscopic facility that will replace the 3.6m Canada-France-Hawaii Telescope. With backend spectrographs operating at low (R ~ 3000), moderate (R ~ 6000) and high (R ~ 20/40 k) spectral resolution across the 0.36 – 1.8 µm range, MSE will be poised to address a variety of science questions among which the nature of dark matter, the origin of the elements in the periodic table, the mass of the neutrino, whilst enabling a new era of rapid-response and time-domain astronomy. This paper is a status report of the MSE Low Moderate Resolution spectrograph design, from the Conceptual Design Review (CoDR) towards the Preliminary Design Phase (PDP)

GOLF-NG spectrometer, a space prototype for studying the deep solar dynamics

The GOLF-NG (Global Oscillations at Low Frequency New Generation) instrument is an instrument devoted to the space search of solar gravity and acoustic modes, and may be chromospheric modes. This instrument, successor of GOLF/SoHO will contribute to improve our knowledge of the dynamics of the solar radiative zone. It is a 15 points resonant scattering spectrometer, working on the D1 sodium line. The ground prototype is under construction to validate the hard points and will join the Teide Observatory, at Tenerife in 2006 to analyse how to separate the effects of magnetic turbulence on the line from the solar oscillations. We are prepared to put a space version of this instrument including a capability of identification of the modes, in orbit during the next decade. We hope to insert this search in the ILWS program. This instrument represents in combining observations with SDO and PICARD, a key to improve our knowledge of the solar core, in determining its rotation and magnetic field, through precise mode splitting measurements. The magnetic field of the radiative zone is fundamental for progressing on the solar activity sources, a clue for the long-term solar-earth relationship

GOLF-NG spectrometer, a space prototype for studying the deep solar dynamics

The GOLF-NG (Global Oscillations at Low Frequency New Generation) instrument is an instrument devoted to the space search of solar gravity and acoustic modes, and may be chromospheric modes. This instrument, successor of GOLF/SoHO will contribute to improve our knowledge of the dynamics of the solar radiative zone. It is a 15 points resonant scattering spectrometer, working on the D1 sodium line. The ground prototype is under construction to validate the hard points and will join the Teide Observatory, at Tenerife in 2006 to analyse how to separate the effects of magnetic turbulence on the line from the solar oscillations. We are prepared to put a space version of this instrument including a capability of identification of the modes, in orbit during the next decade. We hope to insert this search in the ILWS program. This instrument represents in combining observations with SDO and PICARD, a key to improve our knowledge of the solar core, in determining its rotation and magnetic field, through precise mode splitting measurements. The magnetic field of the radiative zone is fundamental for progressing on the solar activity sources, a clue for the long-term solar-earth relationship

Integration and testing of the DESI multi-object spectrograph: performance tests and results for the first unit out of ten

International audienceThe Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 deg² will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. A consortium of Aix-Marseille University (AMU) and CNRS laboratories (LAM, OHP and CPPM) together with LPNHE (CNRS, Universities Pierre et Marie Curie and Paris-Diderot) and the WINLIGHT Systems company based in Pertuis (France), are in charge of integrating and validating the performance requirements of the full spectrographs. This includes the cryostats, shutters and other mechanisms. The first spectrograph of the series of ten has been fully tested and the performance requirements verified for the following items: focus, image quality, straylight, stability, detector properties and throughput. We present the experimental setup, the test procedures and the results