Galaxy Clusters Near and Far
The Spatially Resolved Dynamics of Dusty Starburst Galaxies in a z ~ 0.4 Cluster: The Beginning of the End?
Helen Johnson
Centre for Extragalactic Astronomy, Durham University
In the present day star formation has all but been extinguished in dense environments, with the populations of massive clusters dominated by passive ellipticals and S0s. Yet observations at intermediate redshift reveal a striking increase in the numbers of blue, star-forming galaxies. Mechanisms such as tidal interactions, ram pressure stripping and strangulation are often invoked to explain the evolution of cluster galaxies, however we still lack a clear understanding of the relative contribution of these processes and the timescales on which they operate. To investigate what drives the reversal of the morphology-density relation at intermediate/high redshift, we present a multi-wavelength analysis of 28 dusty starburst galaxies in the massive cluster Cl0024+17 at z=0.4. Combining H-alpha dynamical maps from the VLT/FLAMES multi-IFU system with far-infrared imaging from Herschel/SPIRE and millimetre spectroscopy from IRAM/NOEMA, we measure the dynamics, star formation rate and gas masses of our sample. We piece together the history of these galaxies and ask which further processes must occur, and when, if they are to eventually make the transition to cluster S0s.


13:30 - 15:00
EX - LT3 (320)