Amplitudes and lifetime of radial modes in red giant star spectra observed by Kepler
Mathieu Vrard (Instituto de Astrofísica e Ciências do Espaço, U.Porto), Barban, C. (Observatoire de Paris), Mosser, B. (Observatoire de Paris), Baudin, F. (Institut d)

The space mission Kepler has provided seismic data of unprecedented quality which brought new ways to precisely measure the stellar seismic parameters in red giant star spectra. With now four years of observations, the precise characterization of the seismic mode parameters can be carried out. Here, we present the results of a large study realized on red giant and subgiant stars which aim to characterize precisely their pressure mode amplitude and linewidth in their spectra. We will detail the automated procedure used to determine these two parameters throughout the star spectra. We will then present the results and analyze them throughout the stellar evolution in function of the star physical parameters. Finally, the implications of the results on the physical processes behind the excitation and damping of the modes will be developed.