Multi-Object Optical And Near-infrared Spectrograph Research Articles

CLIMBER: Galaxy–Halo Connection Constraints from Next-generation Surveys

Abstract In the coming decade, a new generation of massively multiplexed spectroscopic surveys, such as the Prime Focus Spectrograph Galaxy Evolution Survey (PFS), Wide Area Vista Extragalactic Survey-Deep (WAVES), and Multi-Object Optical and Near-infrared Spectrograph (MOONS) for the Very Large Telescope, will probe galaxies in the distant universe in vastly greater numbers than was previously possible. In this work, we generate mock catalogs for each of these three planned surveys to help quantify and optimize their scientific output. To assign photometry into the UniverseMachine empirical model, we develop the Calibrating Light: Illuminating Mocks By Empirical Relations procedure using Ultra Deep Survey with the Visible and Infrared Survey Telescope for Astronomy (UltraVISTA) photometry. Using the published empirical selection functions for each aforementioned survey, we quantify the mass completeness of each survey. We compare different targeting strategies by varying the area and targeting completeness, and quantify how these survey parameters affect the uncertainty of the two-point correlation function. We demonstrate that the PFS and MOONS measurements will be primarily dominated by cosmic variance, not shot noise, motivating the need for increasingly large survey areas. On the other hand, the WAVES survey, which covers a much larger area, will strike a good balance between cosmic variance and shot noise. For a fixed number of targets, a 5% increased survey area (and ∼5% decreased completeness) would decrease the uncertainty of the correlation function at intermediate scales by 0.15%, 1.2%, and 1.1% for our WAVES, PFS, and MOONS samples, respectively. Meanwhile, for a fixed survey area, 5% increased targeting completeness improves the same constraints by 0.7%, 0.25%, and 0.1%. All of the utilities used to construct our mock catalogs and many of the catalogs themselves are publicly available.

Collision possibility analysis and collision avoidance for multi-object fibre-fed spectrographs with theta–phi positioners

ABSTRACT Multi-object spectroscopy has become a valuable technique in numerous modern astronomical facilities. Most spectrographs have thousands of fibre positioners packed at a focal plane with shared working space. Therefore, positioners might collide with each other, which can lead to them being damaged. In this study, we first analysed the types of collisions between hexagonal patterned theta–phi positioners and the possibility of these collisions. Based on this, we proposed a motion planning method by deploying a proposed ‘safety zone’ within the positioner patrol area. Simulated experiments validated that our method could completely solve collisions between positioners with equal arms, such as the Large-sky-Area Multi-Object fibre Spectroscopic Telescope (LAMOST) and the Dark Energy Spectroscopic Instrument (DESI), or between positioners with unequal arms, such as the Multi-Object Optical and Near-infrared Spectrograph (MOONS).