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-ω 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.