The hot limit of solar-like oscillations from Kepler photometry

Kepler short-cadence photometry of 2347 stars with effective temperatures in the range 6000-10000 K was used to search for the presence of solar-like oscillations. The aim is to establish the location of the hot end of the stochastic convective excitation mechanism and to what extent it may overlap the delta Scuti/gamma Doradus instability region. A simple but effective autocorrelation method is described which is capable of detecting low-amplitude solar-like oscillations, but with significant risk of a false detection. The location of the frequency of maximum oscillation power, $ u_{rm max}$, and the large frequency separation, $Delta u$, is determined for 167 stars hotter than 6000 K, of which 70 are new detections. Results indicate that the hot edge of excitation of solar-like oscillations does not appear to extend into the delta Scuti/gamma Doradus instability strip.