First measurement of the ASTRO-H soft x-ray telescope performance

Abstract

ASTRO-H is a Japanese X-ray astrophysics satellite under the development led by Japan and US. It will have two Soft X-ray Telescopes (SXTs), among other instruments, that are being developed by NASA's Goddard Space Flight Center. One is for an X-ray micro-calorimeter instrument and the other for an X-ray CCD camera, both covering the X-ray energy band below 15 keV. The SXT Engineering Model (EM) quadrant was successfully completed and has shown big improvements in the X-ray performance from <i>Suzaku </i>owing to number of changes made. The EM was tested at the Goddard 100-m X-ray beamline (diverging beam) and the ISAS/JAXA beamline (pencil beam scan). The angular resolution was found to be 1.1 arcmin at Goddard, while 1.27 arcmin at ISAS, and the effective area was 157 and 122 cm² at 1 and 6 keV, respectively. The discrepancy in the angular resolution can be explained by the difference of the measurement method, i.e. the diverging beam vs. the pencil beam scan. The development of the first Flight Model (FM) is underway. The first three quadrants are completed so far and show about 1 arcmin (HPD) angular resolution. We expect that the first FM SXT will have about 1 arcmin resolution, which will be completed in September, 2012.