Surveys of the sky across the electromagnetic spectrum from ground- and space-based observatories are central to progress in astronomy. Ongoing and planned surveys in the coming decade are motivated by some of the most compelling questions confronting astronomers, for example: Why is the expansion of the universe accelerating? What is the nature and distribution of dark matter? How do galaxies form and evolve? What is the fossil record of the assembly of the Milky Way?
There is an acute need for large-scale surveys in both hemispheres with wide-field, highly-multiplexed spectrographs to complement and exploit amongst others, the ground-based imaging surveys of LSST, Pan-Starrs, SDSS, UKIRT and VISTA, the APERTIF, ASKAP, LOFAR, MeerKAT and SKA radio surveys, and the space-based surveys of Gaia, EUCLID, eROSITA and WFIRST. Several next-generation survey spectrographs are already in rapid development around the world, and are anticipated to be in use well before the end of this decade.
Two European initiatives, WEAVE on the William Herschel Telescope and 4MOST on VISTA, will map the kinematic and chemical substructure in the Milky Way, enhancing the scientific legacy of Gaia's census of our galaxy, and will characterise the objects found in the next-generation radio surveys. Another European development, the near-infrared multi-object spectrograph MOONS on ESO's VLT, will extend the Galactic chemo-dynamical surveys, and will also provide insight into galaxy evolution up to the epoch of re-ionisation. In the U.S. DESI on the Mayall Telescope will focus on measuring baryonic acoustic oscillations and redshift-space distortions to shed light on the accelerating cosmic expansion and dark energy, and the growth of structure in the universe. PFS on Japan's Subaru Telescope, with the unique capability of a high multiplex over a 1.3-degree field on a large telescope, will perform wide and deep redshift surveys at optical and near-infrared wavelengths, addressing the growth of structure and the nature of dark energy, and will also survey the assembly histories of the baryonic and dark matter components of the Milky Way and M31.
Already well under way, the Gaia-ESO survey with FLAMES on the VLT is systematically targeting the major components of the Milky Way to provide a homogeneous overview of the distributions of its kinematics and abundances. Complementary analyses with the bright sample of the massive RAVE survey carried out on the UKST in Australia will be a powerful tool in furthering our understanding of the kinematics of the Galaxy. Also in Australia, HERMES on the AAT has just begun a chemical-tagging survey of the Milky Way with unprecedented high resolutions for a wide-field spectrograph to extend our understanding of the assembly and evolution of the Galaxy. And in China, GSJT/LAMOST is taking data for an extensive kinematic study of the Milky Way, with an impressive 4000 fibres over a 5-degree field.
The impact of these wide-area survey instruments and other ambitious optical or near-infrared multiplexed spectrographs such as EMIR and MEGARA on GranTeCan, HETDEX on the Hobby-Eberly Telescope, FLAMINGOS-2 on Gemini-South, MOSFIRE at the W.M. Keck Observatory, SAMI and Hector on the AAT and the SDSS APOGEE-2, eBOSS and MaNGA surveys will naturally extend to numerous other areas of broad community interest than those mentioned here. The stage is set for a golden era of transformational discovery which will unravel many of the fundamental puzzles of contemporary astrophysics.
This conference will bring together a diverse cross-section of the international astronomical community to discuss the underlying science aspirations of the next-generation massive spectroscopic surveys, explore strategies for optimising their scientific impact, summarise lessons learned from previous large-scale surveys, and share the technical challenges of developing and operating the sophisticated instruments which will make these studies feasible.