A feasibility design study was undertaken to assess the requirements of a mid-infrared echelle spectrograph (MIRES) with a resolving power of 120,000 and its associated mid-infrared adaptive optics (MIRAO) system on the Thirty-Meter Telescope. Our baseline design incorporates a 2Kx2K Si:As array or array mosaic for the spectrograph and a 1Kx1K Si:As array for the slit viewer. Various tradeoffs ...

The VIRMOS consortium of French and Italian Institutes (PI: O. Le Fèvre, co-PI: G. Vettolani) is manufacturing two wide field imaging multi-object spectrographs for the European Southern Observatory Very Large Telescope (VLT), with emphasis on the ability to carry over spectroscopic surveys of large numbers of sources: the VIsible Multi-Object Spectrograph, VIMOS, and the Near InfraRed MultiObj...

Spectral analysis needs the observation of lines of successive ionization stages in order to evaluate the ionization equilibrium (of a particular species) which is a sensitive indicator for the effective temperature (Teff). Since stars with Teff as high as 100 000K have their flux maximum in the extreme ultraviolet (EUV) wavelength range and due to the high degree of ionization, most of the met...

Laser-based optical diagnostics, such as planar laser-induced fluorescence and, especially, Raman imaging, often require selective spectral filtering. We advocate the use of an imaging spectrograph with a broad entrance slit as a spectral filter for two-dimensional imaging. A spectrograph in this mode of operation produces output that is a convolution of the spatial and spectral information tha...

We present an analysis of Kr I λ1236 line measurements from 50 sight lines in the Hubble Space Telescope Space Telescope Imaging Spectrograph and Goddard High Resolution Spectrograph data archives that have sufficiently high resolution and signal-to-noise ratio to permit reliable krypton-to-hydrogen abundance ratio determinations. The distribution of Kr/H ratios in this sample is consistent wit...

FLAMES (Fibre Large Array Multi Element Spectrograph) is the VLT Fibre Facility, installed and commissioned at the Nasmyth A focus of UT2 (Kueyen Telescope). FLAMES was built and assembled in about four years through an international collaboration between ten institutes in six countries and three continents. It had first light with the fibre link to the red arm of UVES on April 1, and with the ...

Superpositions of stellar tracings are present in every slitless spectrograph. The probability for such overlaps in the GAIA RVS spectrograph focal plane is estimated using photometric observations of 66 stellar fields, mostly close to the Galactic plane. It is shown that overlaps of bright stars (V < 17) are common near the Galactic plane, and no spectrum is free from superpositions of faint s...