Developing an integrated concept for the E-ELT Multi-Object Spectrograph (MOSAIC): design issues and trade-offs

We present a discussion of the design issues and trade-offs that have been considered in putting together a new concept for MOSAIC, the multi-object spectrograph for the E-ELT. MOSAIC aims to address the combined science cases for E-ELT MOS that arose from the earlier studies of the multi-object and multi-adaptive optics instruments. MOSAIC combines the advantages of a highly-multiplexed instrument targeting single-point objects with one which has a more modest multiplex but can spatially resolve a source with high resolution (IFU). These will span across two wavebands: visible and near-infrared

First stellar photons for an integrated optics discrete beam combiner at the William Herschel Telescope

We present the first on-sky results of a four-telescope integrated optics discrete beam combiner (DBC) tested at the 4.2mWilliamHerschel Telescope. The device consists of a four-input pupil remapper followed by a DBC and a 23-output reformatter. The whole device was written monolithically in a single alumino-borosilicate substrate using ultrafast laser inscription. The device was operated at astronomical H-band (1.6 μm), and a deformable mirror along with a microlens array was used to inject stellar photons into the device. We report the measured visibility amplitudes and closure phases obtained on Vega and Altair that are retrieved using the calibrated transfer matrix of the device. While the coherence function can be reconstructed, the on-sky results show significant dispersion from the expected values. Based on the analysis of comparable simulations, we find that such dispersion is largely caused by the limited signal-to-noise ratio of our observations. This constitutes a first step toward an improved validation of theDBCas a possible beam combination scheme for long-baseline interferometry. © 2021 Optical Society of America

The Effect of the Telescope on the Overall Quality of RVS: Gaia Report to ESA (GEPI/Gaia-RVS/TN/007.01)

International audienc

Preliminary optical tolerance budget for the RVS dioptric system

International audienc

Preliminary optical tolerance budget for the RVS dioptric system: Gaia Report to ESA (GEPI/Gaia-RVS/TN/015.01)

International audienc

Comparison Of The Four RVS Optical System Options: Gaia Report to ESA (GEPI/Gaia-RVS/TN/006.01)

International audienc

The Effect of the Telescope on the Overall Quality of RVS: Gaia Report to ESA (GEPI/Gaia-RVS/TN/007.01)

International audienc

Preliminary optical tolerance budget for the RVS dioptric system: Gaia Report to ESA (GEPI/Gaia-RVS/TN/015.01)

International audienc

Comparison Of The Four RVS Optical System Options

International audienc