Data from: The SAMI galaxy survey: a range in S0 properties indicating multiple formation pathways

Full description

It has been proposed that S0 galaxies are either fading spirals or the result of galaxy mergers. The relative contribution of each pathway and the environments in which they occur remain unknown. Here, we investigate stellar and gas kinematics of 219 S0s in the SAMI Survey to look for signs of multiple formation pathways occurring across the full range of environments. We identify a large range of rotational support in their stellar kinematics, which correspond to ranges in their physical structure. We find that pressure-supported S0s with v/σ below 0.5 tend to be more compact and feature misaligned stellar and gas components, suggesting an external origin for their gas. We postulate that these S0s are consistent with being formed through a merger process. Meanwhile, comparisons of ellipticity, stellar mass, and Sérsic index distributions with spiral galaxies show that the rotationally supported S0s with v/σ above 0.5 are more consistent with a faded spiral origin. In addition, a simulated merger pathway involving a compact elliptical and gas-rich satellite results in an S0 that lies within the pressure-supported group. We conclude that two S0 formation pathways are active, with mergers dominating in isolated galaxies and small groups, and the faded spiral pathway being most prominent in large groups (1013 < Mhalo < 1014).

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External Organisations
University of Queensland; ARC Australian Research Council; ARC Centre of Excellence for All-sky Astrophysics; Central Queensland University; The University of Western Australia; Australian National University; Swinburne University of Technology; ARC Centre of Excellence for Astrophysics in Three Dimensions (ASTRO3D); Australian Astronomical Observatory; University of New South Wales; Macquarie University; University of Bristol; Centre for Astrophysics and Supercomputing; University of Sydney; Western Sydney University; University of California Berkeley; Sydney Institute for Astronomy; Curtin University; Sydney Inst Astron SIfA; Australian Astronomical Optics; California Institute of Technology; University of Toledo; Christ University, Bangalore; NASA, National Aeronautics & Space Administration (NASA), Armstrong Flight Res Ctr, SOFIA Operat Ctr, USRA; NASA Armstrong Flight Research Center; NASA Ames Research Center; National Institute on Aging; SOFIA Science Center

Associated Persons
Simon Deeley (Creator); Michael J. Drinkwater (Creator); Sarah M. Sweet (Creator); Warrick J. Couch (Creator); Duncan A. Forbes (Creator); Joss Bland-Hawthorn (Creator); Julia Bryant (Creator); Scott M. Croom (Creator); Jon S. Lawrence (Creator); Nuria P F Lorente (Creator); Anne M. Medling (Creator); Matt S. Owers (Creator); Samuel N. Richards (Creator); Jesse Van De Sande (Creator)