Extraction of seismic indices and stellar granulation parameters for CoRoT and Kepler red giants using the MLEUP method. Main results and perspectives

摘要

In the framework of the SPACEInn project, a Stellar Seismic Indices (SSI - http://ssi.lesia.obspm.fr/ ) database was developed in order to provide the scientific community with oscillations and granulation signatures for a large set of red-giant type stars. For this purpose, we have developed the method MLEUP able to extract simultaneously the seismic indices (the equidistance Δ _(v) , the frequency v _(max) and the height H _(env) of the maximum oscillation power) and granulation parameters (the e-folding time τ_(eff) and the variance of the integrated brightness fluctuations σ~(2)). This method has been tested in terms of precision and accuracy, using Monte Carlo simulations. Then we applied it to all stars observed by CoRoT and all long-cadence Kepler lightcurves. In total, we yield seismic indices and granulation parameters for about 5,000 stars for CoRoT and more than 13,000 for Kepler . In this paper, we focus on the main results for both seismic indices Δ _(v) and v _(max) as well as for the stellar parameters (mass, radius and luminosity) seismically inferred. Then, in the perspective of Gaia, we discuss about the possibility to derive other seismic quantities like e.g. a seismic effective temperature.