Characteristics


 

BlueMUSE will cover in one setting the 350-600 nm spectral range at R~4000, expanding the MUSE spectral range (480-930 nm) towards the blue and near-UV at double the spectral resolution. With a field of view of 2 arcmin2, BlueMUSE will also double the sky area presently offered by MUSE. As with MUSE, BlueMUSE will achieve exquisite end-to-end throughput (e.g. 38% at 480 nm, 20 % at 350 nm), 100% sky coverage, high stability and high efficiency.

BlueMUSE wavelength coverage (shaded blue region) compared to the atmospheric absorption (top panel) and emission (bottom panel) as well as MUSE in the nominal (solid) or extended (dashed) modes.

INTEGRAL FIELD OVER A LARGE FIELD OF VIEW

Using the now well-trained technology of image slicers, the optical design allows to fully cover up to 2 arcmin2 FoV on sky and retrieve the full 3D (spatial and spectral) information in a single exposure.

OPTIMISED FOR MEDIUM RESOLUTION IN THE BLUE

Blue-MUSE will complement the MUSE instrument by observing at bluer wavelengths, from the atmospheric cut-off to the middle of the R band. It will have a much higher spectral resolution, with R=4000 in average over the spectral range.

Comparison between the expected spectral resolution of BlueMUSE (blue) compared to MUSE (red), as a function of wavelength.

HIGH TRANSMISSION

Like MUSE, the use of image slicers and the optimization of the instrument for a single observing mode allow for an optimal transmission overall, even higher than traditional slit spectographs when accounting for the slit losses.

Comparison of end-to-end throughputs (including telescope and atmosphere) as measured for all optical spectrographs on VLT, including MUSE in nominal (red solid) or extended (red dashed) mode, or expected for BlueMUSE (blue curve). A slit loss of 15% has been included for slit spectrographs.