A new spacecraft called XRISM (X-ray Imaging and Spectroscopy Mission, pronounced "charism") is designed to separate high-energy light into the equivalent of an X-ray rainbow
A new spacecraft called XRISM (X-ray Imaging and Spectroscopy Mission, pronounced "charism") is designed to separate high-energy light into the equivalent of an X-ray rainbow. The mission, led by Japan's space agency, will do this using a device called Resolve ("separate").
Charisma's launch is scheduled for August 26 (Japan time) from the Tangeshima Space Center.
Richard Kelly, NASA's Chrism principal investigator who works at the Goddard Space Flight Center, emphasizes the importance of the mission: "Resolve will allow us a new look into some of the most energetic objects in the universe, including black holes, galaxy clusters and the results of exploding stars. The data that the mission will collect after the launch will add to our knowledge about how they behave and what they are made of."
NASA and Japan Space Agency workers at the Tsukuba Space Center in Japan calibrated the Charisma Resolve instrument, pictured here, at a temperature just above absolute zero. They had to make these measurements before installing the instrument on the spacecraft. The information obtained from the calibration describes the finer points of performance of Resolve, which are needed by scientists who will use Charisma to explore the universe while in space.
Credit: JAXA
Resolve is an X-ray microcalorimeter spectrometer instrument developed in collaboration between NASA and the Japanese agency. It measures tiny temperature changes that occur when an X-ray beam hits a 6x6 pixel detector. To measure this tiny increase and determine the energy of the X-ray beam, the detector needs to be cooled to around Minus 270 degrees Celsius, just slightly above absolute zero.
The device reaches its operating temperature after a multi-stage mechanical cooling process in a container of liquid helium the size of a refrigerator.
By collecting thousands or even millions of X-rays from a cosmic source, Resolve can measure high-resolution spectra of the object. Spectra are measurements of light intensity over a range of energies. Prisms separate visible light into its various energies, better known to us as the colors of the rainbow. Scientists used prisms in early spectrometers to look for spectral lines, which appear when atoms or molecules absorb or emit energy.
Astronomers today use spectrometers, suitable for all types of light, to study the physical states, movements and compositions of objects. Resolve will perform X-ray spectroscopy with energies ranging from 400 to 1200 electron volts by measuring the energies of individual X-rays to create a spectrum. (For comparison, the energies of visible light range from about two to three electron volts).
Brian Williams, NASA's Charisma Project Scientist at Goddard, emphasized the unique capabilities of the mission: "The spectra that Charisma will collect from some of the phenomena we will observe will be the most detailed we have ever seen. This mission will give us insights into some of the most difficult places to study, such as the internal structures of neutron stars and near-light-speed jets of particles driven by black holes in active galaxies."
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