An On-Orbit Determination of the On-axis Point Spread Function of the Hinode X-Ray Telescope

The Hinode X-Ray Telescope provides unprecedented observations of the solar corona in x-rays, due in part to its fine resolution. The x-ray point spread function (PSF) was measured before launch at the NASA X-Ray Calibration Facility to have a FWHM of 0.8 arc-seconds. This paper describes the work to verify the PSF measurements using on-orbit observations of planetary transits and solar eclipses. Analysis of a Mercury transit gives a PSF FWHM = 1.0 ± 0.12 arcseconds. Hinode is an international project supported by JAXA, NASA, PPARC, and ESA. We are grateful to the Hinode team for all their efforts in the design, development, and operation of the mission.