Search Publications
Principal component analysis of up-the-ramp sampled infrared array data
Rauscher, Bernard J.; Arendt, Richard G.; Fixsen, Dale J. +3 more
We describe the results of principal component analysis (PCA) of up-the-ramp sampled infrared (IR) array data from the Hubble Space Telescope wide field camera 3 (WFC3 IR), James Webb Space Telescope NIRSpec, and prototype Wide Field Infrared Survey Telescope's wide field instrument detectors. These systems use, respectively, Teledyne H1R, H2RG, a…
Subpixel real-time jitter detection algorithm and implementation for polarimetric and helioseismic imager
Volkmer, Reiner; Roma, David; Carmona, Manuel +12 more
The polarimetric and helioseismic imager instrument for the Solar Orbiter mission from the European Space Agency requires a high stability while capturing images, specially for the polarimetric ones. For this reason, an image stabilization system has been included in the instrument. It uses global motion estimation techniques to estimate the jitte…
Hitomi (ASTRO-H) X-ray Astronomy Satellite
Done, Chris; Safi-Harb, Samar; Hamaguchi, Kenji +267 more
The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decade…
Soft X-ray Imager aboard Hitomi (ASTRO-H)
Dotani, Tadayasu; Yamauchi, Makoto; Uchida, Hiroyuki +25 more
The Soft X-ray Imager (SXI) is an imaging spectrometer using charge-coupled devices (CCDs) aboard the Hitomi x-ray observatory. The SXI sensor has four CCDs with an imaging area size of 31 mm×31 mm arranged in a 2×2 array. Combined with the x-ray mirror, the Soft X-ray Telescope, the SXI detects x-rays between 0.4 and 12 keV and covers a 38‧<…
Ground calibration of the Astro-H (Hitomi) soft x-ray spectrometer
Tsujimoto, Masahiro; Eckart, Megan E.; Hoshino, Akio +25 more
The Astro-H (Hitomi) Soft X-ray Spectrometer (SXS) was a pioneering imaging x-ray spectrometer with 5 eV energy resolution at 6 keV. The instrument used a microcalorimeter array at the focus of a high-throughput soft x-ray telescope to enable high-resolution nondispersive spectroscopy in the soft x-ray waveband (0.3 to 12 keV). We present the suit…
Hard x-ray imager onboard Hitomi (ASTRO-H)
Enoto, Teruaki; Yamaoka, Kazutaka; Fukazawa, Yasushi +34 more
The hard x-ray imaging spectroscopy system of "Hitomi" x-ray observatory is composed of two sets of hard x-ray imagers (HXI) coupled with hard x-ray telescopes (HXT). With a 12-m focal length, the system provides fine (1 ‧ . 7 half-power diameter) imaging spectroscopy covering about 5 to 80 keV. The HXI sensor consists of a camera, whi…
Performance of the helium dewar and the cryocoolers of the Hitomi soft x-ray spectrometer
Tsujimoto, Masahiro; Eckart, Megan E.; Hoshino, Akio +35 more
The soft x-ray spectrometer (SXS) was a cryogenic high-resolution x-ray spectrometer onboard the Hitomi (ASTRO-H) satellite that achieved energy resolution of 5 eV at 6 keV, by operating the detector array at 50 mK using an adiabatic demagnetization refrigerator (ADR). The cooling chain from room temperature to the ADR heat sink was composed of tw…
Design, implementation, and performance of the Astro-H SXS calorimeter array and anticoincidence detector
Eckart, Megan E.; Kilbourne, Caroline A.; Leutenegger, Maurice A. +14 more
The calorimeter array of the JAXA Astro-H (renamed Hitomi) soft x-ray spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV, enabling essential plasma diagnostics. The SXS had a square array of 36 x-ray calorimeters at th…
Vibration isolation system for cryocoolers of soft x-ray spectrometer on-board ASTRO-H (Hitomi)
Eckart, Megan E.; Kilbourne, Caroline A.; Kokubun, Motohide +32 more
The soft x-ray spectrometer (SXS) onboard ASTRO-H (named Hitomi after launch) is a microcalorimeter-type spectrometer, installed in a dewar to be cooled at 50 mK. The energy resolution of the SXS engineering model suffered from microvibration from cryocoolers mounted on the dewar. This is mitigated for the flight model (FM) by introducing vibratio…
Supermirror design for Hard X-Ray Telescopes on-board Hitomi (ASTRO-H)
Maeda, Yoshitomo; Ishida, Manabu; Kunieda, Hideyo +14 more
We designed depth-graded multilayers, so-called supermirrors, with platinum/carbon (Pt/C) layer pairs for the Hard X-Ray Telescope (HXT) that was on-board the sixth Japanese X-Ray Astronomy Satellite Hitomi (ASTRO-H). The HXT has multinested thin foil optics, and the grazing angles of the x-ray mirrors are 0.07 to 0.27 deg. Supermirrors for HXTs a…