An optimized tiling pattern for multiobject spectroscopic surveys: application to the 4MOST survey
Year: 2020
Type: article
Abstract: ABSTRACT Large multiobject spectroscopic surveys require automated algorithms to optimize their observing strategy. One of the most ambitious upcoming spectroscopic surveys is the 4MOST survey. The 4MOST survey facility is a fibre-fed spectroscopic instrument on the VISTA telescope with a large enough field of view to survey a large fraction of the southern sky within a few years. Several Galactic and extragalactic surveys will be carried out simultaneously, so the combined target density will strongly vary. In this paper, we describe a new tiling algorithm that can naturally deal with the large target density variations on the sky and which automatically handles the different exposure times of targets. The tiling pattern is modelled as a marked point process, which is characterized by a probability density that integrates the requirements imposed by the 4MOST survey. The optimal tilling pattern with respect to the defined model is estimated by the tiles configuration that maximizes the proposed probability density. In order to achieve this maximization a simulated annealing algorithm is implemented. The algorithm automatically finds an optimal tiling pattern and assigns a tentative sky brightness condition and exposure time for each tile, while minimizing the total execution time that is needed to observe the list of targets in the combined input catalogue of all surveys. Hence, the algorithm maximizes the long-term observing efficiency and provides an optimal tiling solution for the survey. While designed for the 4MOST survey, the algorithm is flexible and can with simple modifications be applied to any other multiobject spectroscopic survey.
Institutions: Tartu Observatory, University of Tartu, Centre National de la Recherche Scientifique, Institut Élie Cartan de Lorraine, Université de Lorraine, Lund University, Leibniz Institute for Astrophysics Potsdam, Heidelberg University, Max Planck Institute for Extraterrestrial Physics, Lancaster University, Université Côte d'Azur, Lagrange Laboratory, Observatoire de la Côte d’Azur, University of Sussex, Durham University, Lyon 1 Université, Nicolaus Copernicus University, Centre de Recherche Astrophysique de Lyon, University of Portsmouth, Swinburne University of Technology
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: California Department of Fish and Game, European Commission, Deutsche Forschungsgemeinschaft, Fundacja na rzecz Nauki Polskiej, Knut och Alice Wallenbergs Stiftelse, Vetenskapsrådet, Ministerstwo Edukacji i Nauki, European Southern Observatory, Medical Research Council, Science and Technology Facilities Council, European Research Council, European Regional Development Fund
Awards: G1862865938, G4221417635, G434337789, G4772328477, G4795087365, G4834903470, G5146631217, G6075447204, G6152540015, G6425007583, G6570372938, The star formation history of the Milky Way thick disk, G7288258658, G7500481665, G7683230809, SFB 881: Das Milchstraßensystem, G7800417877, G7956055077, G837177648
OpenAlex ID: W3040381680