National Aeronautics and Space Administration

XRISM

The X-Ray Imaging and Spectroscopy Mission (XRISM), previously known as the X-ray Astronomy Recovery Mission (XARM), is an X-ray astronomy satellite collaboration between the Japanese Aerospace Exploration Agency (ISAS/JAXA), NASA and the European Space Agency (ESA). The satellite was launched from the Tanegashima Space Center at 8:42 a.m on September 7, 2023 JST in Japan.

There are two primary instruments, Resolve (a Soft X-ray Spectrometer) and Xtend (Soft X-ray Imager). The spectrometer is cryogenically cooled with liquid helium, and the helium supply is anticipated to last for three years, though the mission may be extended thereafter with mechanical cooling. The mission is intended to recover most of the science capability of Hitomi in the 0.3–12 keV energy range, lost during an early mission mishap.

Mission Characteristics

Lifetime

Energy Range

Special Features

Payload

• Resolve. The unit consists a 6 pixel x 6 pixel X-ray calorimeter spectrometer. Resolve is directly analogous to the SXS instrument on Hitomi, using many of the SXS spare components. There are 35 active pixels and one inactive corner pixel. The calorimeter is enclosed in a dewar, cooling the detector at 50 mK, with a liquid helium tank anticipated to last three years. Thereafter, the instrument is cooled via mechanic cooling with reduced sensitivity.
  
  • Energy range : 0.3–12 keV
    
  • Effective area : 210 cm² at 6 keV; 160 cm² at 1 keV
    
  • Field of view and Angular resolution : 3 x 3 arcmin² and <1.3 arcmin
  • Energy Resolution: <7 eV at 6 keV
  Additional components of the Resolve detector include:
  • A gate valve placed on top of the dewar to protect during initial operation and removed in normal operation.
  • A six filter wheel, mounted 90 cm from the spectrometer, to use in normal operation modes. The filters are : two empty positions (i.e. no filter), a radioactive ⁵⁵Fe calibration source, a molybdenum neutral density filter to attenuate X-rays for bright sources, and beryllium and polyimide-aluminium filters to exclude X-rays outside specific energy ranges.
  • A Modulation X-ray Source (MXS) mounted below the filter wheel. When turned on, this illuminates the entire detector for calibration. It consists of 4 LEDs operating in pairs with targets composed of Cu/Cr and Al/Mg.

• XTend. The unit consists of 4 CCDs in 2×2 configuration. Each CCD is an array of 640×640 pixels. It is directly analogous to the SXI on Hitomi.
  
  • Energy range : 0.4–12 keV
    
  • Effective area : 360 cm² at 6 keV
    
  • Angolar resolution : <1.3 arcmin
  • Field of View : 38×38 arcmin²
  • Energy Resolution: <200 eV at 6 keV

Science Highlights

• Insight on galaxy and cluster evolution
• Diffuse gas in local environments
• The physics and dynamics of cosmic plasmas
• The formation and evolution of compact objects, including ultraluminous sources and magnetic cataclysmic variables

Archive