Institute of Astronomy

The formation of large galactic disks: survival or revival?

SpeakerTalk DateTalk Series
Francois Hammer (GEPI, Observatoire de Paris)28 September 2011Institute of Astronomy Seminars


Using the deepest and most complete observations of distant galaxies, we investigate how large disks could have been formed. Observations include spatially-resolved kinematics, detailed morphologies and photometry from UV to mid-IR. Six billions years ago, half of the present-day spirals were experiencing major mergers, evidenced by their anomalous kinematics and morphologies as well as their relatively high gas fractions. They are consequently modelled using the state of the art hydrodynamics models. This leads to a new channel of disk formation, e.g. disks reformed after gas-rich mergers, which can be compared to predictions from the LCDM model. The scenario can be ultimately compared to properties of nearby galaxies, including the Milky Way, M31 and galaxies showing ultra-faint, gigantic structures in their haloes.