GAMA survey

GAMA survey The Galaxy And Mass Assembly (GAMA) survey is a multi-wavelength spectroscopic and imaging program that mapped galaxies across the local Universe to study galaxy formation and cosmology. The project combined observations from the Anglo-Australian Telescope, the Sloan Digital Sky Survey, the European Southern Observatory, and space missions to produce redshift catalogs and photometric measurements for statistical studies of structure, stellar mass, and environment.

Overview

The GAMA initiative was formulated by astronomers affiliated with the University of Edinburgh, the Australian National University, the University of St Andrews, the University of Portsmouth, and the European Southern Observatory to address questions in galaxy evolution, large-scale structure, and dark matter. Early planning involved teams that had worked on the Sloan Digital Sky Survey, the Two Micron All Sky Survey, the Two Degree Field Galaxy Redshift Survey, and the VIMOS VLT Deep Survey, leveraging expertise in survey strategy from projects such as the Dark Energy Survey, the Pan-STARRS project, and the Cosmic Evolution Survey. Funding and institutional support came from organizations including the Science and Technology Facilities Council, the Australian Research Council, the European Research Council, and national observatories like the Anglo-Australian Observatory and the European Southern Observatory.

Survey Design and Data Acquisition

Survey fields were selected to overlap legacy fields and facilities operated by the Anglo-Australian Telescope, the Very Large Telescope, the United Kingdom Infrared Telescope, the Galaxy Evolution Explorer, and the Herschel Space Observatory to enable cross-comparison with the Sloan Digital Sky Survey, the Wide-field Infrared Survey Explorer, and the VISTA Hemisphere Survey. Target selection employed magnitude limits and surface brightness criteria informed by results from the Two Micron All Sky Survey, the Deep Extragalactic Evolutionary Probe, and the COMBO-17 survey, with spectroscopy obtained using the Two Degree Field instrument and later spectrographs that followed instrument programs like the VIMOS instrument and the DEIMOS instrument used by the Keck Observatory. Observing strategy balanced depth and area to complement efforts by the Dark Energy Spectroscopic Instrument and the WiggleZ Dark Energy Survey, while coordinating photometry from the GALEX mission, the Herschel Multi-tiered Extragalactic Survey, and the Spitzer Space Telescope.

Data Processing and Catalogs

Data reduction pipelines built on software approaches developed for the Sloan Digital Sky Survey, the 2dF Galaxy Redshift Survey, and the VIMOS VLT Deep Survey produced redshift measurements, spectral line indices, and multi-band photometry. Catalog construction incorporated stellar population modeling comparable to techniques used by the Millennium Simulation teams, the Illustris project, and the EAGLE collaboration to derive stellar masses, star-formation rates, and dust attenuation parameters. Value-added catalogs included group catalogs and halo mass estimates using algorithms related to those in the COSMOS field analyses and the Galaxy Zoo morphological classifications, enabling comparisons with catalogs from the VIPERS survey, the zCOSMOS survey, and the PRIMUS program.

Scientific Results

GAMA results addressed the stellar mass function, luminosity functions, and the role of environment in galaxy evolution, producing outcomes that complemented findings from the Sloan Digital Sky Survey, the Two Degree Field Galaxy Redshift Survey, and the Galaxy And Mass Assembly predecessors. Studies quantified galaxy merger rates and mass assembly histories that informed theoretical work from the Millennium Simulation, the IllustrisTNG project, and the EAGLE simulation, and provided observational constraints relevant to models by the Santa Cruz semi-analytic group and the Durham GALFORM team. Research on group dynamics and halo occupation statistics produced comparisons with lensing results from the Canada–France–Hawaii Telescope Lensing Survey, the Dark Energy Survey, and the Kilo-Degree Survey, while measurements of the cosmic spectral energy distribution linked to analyses from the Herschel-ATLAS project, the Spitzer SWIRE survey, and the AKARI mission.

Legacy and Collaborations

The survey established long-term data releases and collaborations with institutions including the University of Cambridge, the Max Planck Institute for Astronomy, the Australian Astronomical Observatory, and the Leibniz Institute for Astrophysics Potsdam, fostering synergies with the Sloan Digital Sky Survey, the Dark Energy Survey, and future facilities such as the Vera C. Rubin Observatory and the Euclid mission. GAMA catalogs continue to serve as reference datasets for studies conducted by groups involved in the Millennium Simulation, the Illustris team, the EAGLE collaboration, and experimental efforts at the European Southern Observatory and the National Astronomical Observatory of Japan, ensuring integration with archival resources like those maintained by the Space Telescope Science Institute and the Centre de Données astronomiques de Strasbourg.

Category:Astronomical surveys