Solar-like oscillations in red giants observed with Kepler: Comparison of global oscillation parameters from different methods

Methods

For this investigation we use Kepler data obtained during the first four months of operation. These data have been analysed by different groups using already published methods and the results are compared. We also performed simulations to investigate the uncertainty on the resulting parameters due to different realizations of the stochastic signal.

Results: We obtain results for the frequency of maximum oscillation power (nu_max) and the mean large separation ( ) from different methods for over one thousand red-giant stars. The results for these parameters agree within a few percent and seem therefore robust to the different analysis methods and definitions used here. The uncertainties for nu_max and due to differences in realization noise are not negligible and should be taken into account when using these results for stellar modelling.