MOSAIC: the ELT Multi-Object Spectrograph

Following a successful Phase A study, we introduce the delivered conceptual design of the MOSAIC1 multi-object spectrograph for the ESO Extremely Large Telescope (ELT). MOSAIC will provide R~5000 spectroscopy over the full 460-1800 nm range, with three additional high-resolution bands (R~15000) targeting features of particular interest. MOSAIC will combine three operational modes, enabling integrated-light observations of up to 200 sources on the sky (high-multiplex mode) or spectroscopy of 10 spatially-extended fields via deployable integral-field units: MOAO6 assisted high-definition (HDM) and Visible IFUs (VIFU). We will summarise key features of the sub-systems of the design, e.g. the smart tiled focal-plane for target selection and the multi-object adaptive optics used to correct for atmospheric turbulence, and present the next steps toward the construction phase