Initial Helioseismic Observations by Hinode/SOT

Results from initial helioseismic observations by the Solar Optical Telescope on-board Hinode are reported. It has been demonstrated that intensity oscillation data from the Broadband Filter Imager can be used for various helioseismic analyses. The k–! power spectra, as well as the corresponding time–distance cross-correlation function, which promise high-resolution time–distance analysis below the 6-Mm travelling distance, were obtained for G-band and Ca II-H data. Subsurface supergranular patterns were observed from our first time–distance analysis. The results show that the solar oscillation spectrum is extended to much higher frequencies and wavenumbers, and the time–distance diagram is extended to much shorter travel distances and times than were observed before, thus revealing great potential for high-resolution helioseismic observations from Hinode.