8-12 juin, 2014


Fourier Transform Spectroscopy, passive galaxies and new perspectives on cluster galaxy evolution

Sébastien Lavoie (University of Victoria)

With their large FOV and throughput, imaging Fourier transform spectrometers (iFTS) are powerful instruments to study single extended objects as well as groups of multiple sources. We present results from the iFTS SpIOMM at the Observatoire du Mont-Mégantic demonstrating the novel use of iFTS to study the spectroscopic gradient of absorption lines in the massive elliptical galaxy M87. Later this year, the new iFTS SITELLE is to be delivered at the CFHT. Its high quality optics and filters, combined with the larger 3.6m mirror and better seeing, will provide both a resolved view of local passive galaxies and a powerful spectroscopic engine to study galaxies in intermediate redshift clusters. We intend to exploit the high efficiency of SITELLE to obtain spectra of the members of a large sample of X-ray clusters from the XXL survey. A large, well controlled sample is very important to study such tenuous effects as the spectroscopic quenching signature in green valley galaxies and the influence of dynamical structure on member galaxy evolution. We introduce the properties of the XXL survey and the opportunities for learning about clusters evolution by presenting a spectroscopic and photometric study of the brightest cluster galaxies (BCGs) in the sample of 100 brightest X-ray clusters in XXL. We demonstrate that the properties of BCGs in clusters are closely related to multiple tracers of the cluster environment including X-ray morphology (the presence of cool cores) and dynamical state (active cluster-cluster merging).
(doit être confirmé par le SOC)