X-ray telescope XRISM successfully launched
The XRISM X-ray telescope is successfully launched on the early morning of September 7th from Tanegashima Space Center in Japan onboard a JAXA H-IIA rocket. SRON Netherlands Institute for Space Research is part of the consortium and has developed the filter wheel including calibration system. 
In 2016, the Japanese X-ray mission Hitomi gave tantalising clues about the hot and energetic universe before a control system error ended the mission. Since then, astronomers have been eagerly awaiting the launch of its successor—the X-Ray Imaging and Spectroscopy Mission (XRISM). For its development, the Japanese space agency JAXA once again collaborated with NASA and ESA. And just like for Hitomi, SRON delivered the filter wheel with calibration system together with the University of Geneva.
XRISM will point its X-ray eyes towards the universe to address the following scientific questions: How are galaxy clusters formed? What does their structure look like? The telescope observes the the intracluster medium (ICM), the hot gas within a cluster. While telescopes such as Hubble and James Webb mainly show us galaxies within clusters, the ICM accounts for the majority of the mass of the cluster. Due to its high temperature, it is best seen through X-rays. XRISM also looks at other high-energy processes, such as supernovae and supermassive black holes emitting powerful jets. The XRISM Resolve instrument measures the energy of the X-rays at such high resolution (5-7 eV at 0.3-12 keV) that astronomers are able to calculate velocities of the ejected matter to unprecedented accuracy. This gives them unique insight into the flow of matter through galaxies, into the ICM, and back again. 
The Dutch contribution to XRISM consists of the filter wheel for Resolve. The filter wheel puts different filters in front of the camera, allowing astronomers to select the brightness and wavelengths of the incoming radiation. They will for example use the Molybdenum gray filter if a star or black hole emits more X-rays than the detector can handle. They will choose the Beryllium or Polyimide aluminum filter to block certain wavelengths. A slightly radioactive iron-55 source is included in the filter wheel to calibrate the X-ray camera. Together with the Dutch company Photonis, SRON has also developed an X-ray source allowing continuous calibration of the detector.
As part of the XRISM consortium, Dutch astronomers have access to the first data. After that period, all European scientists will propose for observing time to an open competition.
The Dutch contribution was made possible by additional funds from the Netherlands Space Office.
Caption header image: Artist impression of XRISM. Credit: JAXA
Caption above: Part of the SRON team behind the development of the filter wheel and calibration source for the Resolve instrument.
Caption right: The filter wheel for the Resolve instrument.
