ATLAS3D

ATLAS3D is a comprehensive, volume-limited survey of nearby early-type galaxies that combined integral-field spectroscopy, millimetre and radio observations, and multiwavelength imaging to study galaxy kinematics, stellar populations, and cold gas. Conceived and led by a team including Roger Davies and Timothy A. Davis, the project used facilities such as the William Herschel Telescope, the IRAM 30m telescope, and archives from Herschel Space Observatory and Spitzer Space Telescope to assemble homogeneous data for a statistically significant sample. The survey produced influential results on the role of rotation, environment, and gas in shaping the morphology and evolution of early-type systems, informing follow-up programs and theoretical work by groups at institutions like University of Oxford, University of Durham, and European Southern Observatory.

Overview

ATLAS3D targeted a complete, volume-limited sample of 260 nearby early-type galaxies within 42 Mpc selected from the Two Micron All Sky Survey and the Third Reference Catalogue of Bright Galaxies. The collaboration combined integral-field spectroscopy from SAURON on the William Herschel Telescope with molecular gas observations from the IRAM 30m telescope and neutral hydrogen mapping from the Westerbork Synthesis Radio Telescope. ATLAS3D connected stellar kinematics, ionized gas, cold molecular gas, dust emission, and photometric structure, enabling comparisons with theoretical frameworks from groups working on Lambda-CDM cosmology, semi-analytic models, and hydrodynamical simulations used by teams at Max Planck Institute for Astrophysics, Harvard–Smithsonian Center for Astrophysics, and Princeton University.

Survey design and sample selection

The parent selection used photometry from Two Micron All Sky Survey and redshift information from the NASA/IPAC Extragalactic Database to identify early-type candidates with K-band magnitude cuts and distance limits cross-checked against Surface Brightness Fluctuations distances from the Hubble Space Telescope Key Project. Morphological classification relied on imaging from the Sloan Digital Sky Survey and the Digitized Sky Survey, with eyeball vetting by team members including Michele Cappellari and Richard M. McDermid. Environment metrics referenced group catalogs from the 2MASS Redshift Survey and the Virgo Cluster Catalog to tag galaxies near structures like Virgo Cluster, Coma Cluster, and known groups identified by the CfA Redshift Survey. The final sample emphasized uniform coverage of luminosity, morphology, and local density to enable statistical tests of processes invoked by researchers at Institute of Astronomy, Cambridge and Max Planck Institute for Extraterrestrial Physics.

Observations and data reduction

Integral-field spectroscopy was obtained with SAURON producing two-dimensional stellar velocity and velocity-dispersion maps, reduced using bespoke pipelines developed by the team and validated against standards from European Southern Observatory pipelines and techniques described by researchers at Leiden Observatory. Molecular gas surveys used the IRAM 30m telescope and heterodyne receivers to detect CO lines, with calibration tied to methods from the Institut de Radioastronomie Millimétrique, while neutral hydrogen observations drew on archival data from the Westerbork Synthesis Radio Telescope and new single-dish runs at the Effelsberg 100-m Radio Telescope. Imaging across optical and infrared bands utilized the Hubble Space Telescope, Spitzer Space Telescope, and ground-based telescopes including the Isaac Newton Telescope; data reduction employed photometric calibration procedures aligned with standards from the Pan-STARRS and Two Micron All Sky Survey teams. Kinematic maps, line-strength indices, and gas mass estimates were produced with software maintained by collaborators at University of Oxford, University of Hertfordshire, and Australian National University.

Key scientific results

ATLAS3D demonstrated a dichotomy between fast rotators and slow rotators among early-type galaxies, reframing morphology–kinematics relations explored by investigators at California Institute of Technology and University of California, Santa Cruz. The survey showed that most early-type galaxies are rotationally supported disks consistent with evolutionary pathways involving minor mergers and gas accretion, echoing predictions from simulations by groups at Columbia University and Yale University. ATLAS3D quantified the incidence of cold molecular gas and ongoing star formation in early-type systems, linking CO detections to dust features seen with Herschel Space Observatory and stellar-population ages measured with techniques used at European Southern Observatory. The project provided robust measurements of dark matter fractions within effective radii and dynamical mass-to-light ratios, informing mass-modeling work at Max Planck Institute for Astronomy and University of Bologna. Environmental trends—such as suppressed gas content in dense regions like Virgo Cluster—were characterized, influencing interpretations by teams at University of Toronto and University of Cambridge about the role of tidal interactions and ram-pressure stripping. ATLAS3D's kinematic classifications have been widely adopted in studies by groups at Princeton University, University College London, and University of Tokyo.

Related projects and legacy data

ATLAS3D legacy products fueled follow-up surveys and archival science tied to instruments and programs like CALIFA, MaNGA, SAMI Galaxy Survey, and targeted studies with the Atacama Large Millimeter/submillimeter Array and Very Large Telescope. The dataset complements photometric surveys such as Sloan Digital Sky Survey and radio programs at the Very Large Array and MeerKAT, and it has been incorporated into comparative analyses alongside simulations from the Illustris Project and EAGLE by teams at University of Cambridge and Durham University. ATLAS3D products—kinematic cubes, CO spectra, HI maps, and catalogs—remain available to investigators at institutions including Harvard University, University of Oxford, and European Southern Observatory for studies of galaxy formation, black hole scaling relations explored by researchers at Royal Observatory Edinburgh, and stellar population synthesis analyses used by groups at University of Michigan.

Category:Astronomical surveys