XRISM is a collaborative mission between Japan, NASA, and the European Space Agency (ESA), and its advanced instruments will revolutionize X-ray astronomy, providing unprecedented insight into the hottest and most massive structures in the universe. The Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) observatory has released for the first time the unprecedented data it will collect when it begins scientific operations later this year.

The satellite's science team released snapshots of a galaxy cluster made up of hundreds of galaxies, as well as a spectrum of stellar remnants in a nearby galaxy, giving scientists a detailed look at its chemical makeup.

XRISM's Resolve instrument captured data from supernova remnant N132D in the Large Magellanic Cloud, producing the most detailed X-ray spectrum ever produced for the object. The spectrum shows peaks associated with silicon, sulfur, argon, calcium and iron. The inset on the right is an N132D image taken by XRISM's Xtend instrument. Source: JAXA/NASA/XRISMResolve and Xtend

XRISM mission details

"XRISM will provide the international scientific community with new opportunities to peer into the hidden X-ray sky," said Richard Kelley, U.S. principal investigator for XRISM at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Not only will we be able to see X-ray images of these sources, we will also be able to study their composition, motion and physical state."

XRISM (pronounced "crism") is led by the Japan Aerospace Exploration Agency (JAXA) in collaboration with the National Aeronautics and Space Administration (NASA), with contributions from the European Space Agency (ESA). It will launch on September 6, 2023.

Supernova remnant N132D is located in the central part of the Large Magellanic Cloud, a dwarf galaxy about 160,000 light-years away. XRISM's Xtend captured this remnant in X-rays, as shown in the inset. N132D is approximately 75 light-years across at its widest point. Although very bright in X-rays, the stellar remnant is barely visible in ground-based background views taken in optical light. Source: Illustration, JAXA/NASA/XRISMXtend; Background, C. Smith, S. Points, MCELS Group, and NOIRLab/NSF/AURA

It is designed to detect X-rays with energies up to 12,000 electron volts and will study the hottest regions, largest structures and objects with the strongest gravity in the universe. In comparison, visible light has an energy of 2 to 3 electron volts.

Instruments and early results

The mission has two instruments, Resolve and Xtend, each located at the focus of an X-ray mirror assembly designed and built by Goddard.

"Resolve" is a microcalorimeter spectrometer jointly developed by NASA and the Japan Aerospace Exploration Agency. It operates in a refrigerator-sized container of liquid helium at temperatures just a fraction of a degree above absolute zero.

When X-rays hit Resolve's 6×6 pixel detector, the device heats up, and the amount of temperature rise is related to the energy of the X-rays. By measuring the energy of each X-ray, the instrument can provide previously unobtainable information about the ray source.

XRISM's Xtend imager collected this snapshot of supernova remnant N132D. The expanding remnant is estimated to be about 3,000 years old and was created when a star about 15 times the mass of the Sun ran out of fuel, collapsed and exploded. N132D is approximately 75 light-years across at its widest point. Source: JAXA/NASA/XRISMXtend

The task team used "Resolve" to study N132D. N132D is a supernova remnant and one of the brightest X-ray sources in the Large Magellanic Cloud. The expanding remnant is estimated to be about 3,000 years old and was created when a star about 15 times the mass of the Sun ran out of fuel, collapsed and exploded.

The "resolved" spectrum shows peaks associated with silicon, sulfur, calcium, argon and iron. It is the most detailed X-ray spectrum of this object ever obtained, demonstrating the incredible science the mission will accomplish when it begins normal operations later in 2024.

"These elements were formed in the original star and then ejected when it exploded as a supernova," said Brian Williams, NASA's XRISM project scientist at Goddard. "Resolve will allow us to see the shape of these lines like never before, allowing us to determine not only the abundance of various elements, but also their temperatures, densities and directions of motion with unprecedented precision. From this, we can piece together information about the original star and the explosion."

XRISM's Xtend instrument captured the galaxy cluster Abell 2319 in X-rays, shown here in purple, with a white border representing the detector's range. The background is an image of the ground showing the area in visible light. Image source: JAXA/NASA/XRISMXtend; Background: DSS

XRISM's second instrument, Xtend, is an X-ray imager developed by JAXA. It provides XRISM with a large field of view, allowing it to observe an area about 60% larger than the average apparent area of ​​the full moon.

Xtend captured an X-ray image of Abell 2319, a rich galaxy cluster located about 770 million light-years away in the northern constellation Cygnus. It is the fifth brightest X-ray galaxy cluster in the sky and is currently undergoing a major merger event.

The galaxy cluster is 3 million light-years across and is the highlight of Xtend's wide field of view.

This composite image shows supernova remnant N132D. It uses data from NASA's Chandra X-ray Observatory (purple and green) and the Hubble Space Telescope (red). N132D is one of the brightest X-ray remnants of the Large Magellanic Cloud, a nearby dwarf galaxy. Source: NASA/STSCI/CXC/SAO, handled by Judy Schmidt, CCBY-NC-SA

Technical challenges and future plans

"Even before the commissioning process was complete, Resolve has exceeded our expectations," said Lillian Reichenthal, XRISM program manager at NASA Goddard. "Our goal was to achieve 7 electron volts of spectral resolution with the instrument, but now that it is in orbit, we are achieving 5 electron volts of resolution. This means we will get a more detailed chemical map with every spectrum captured by XRISM."

Despite problems with the aperture gate on the Resolve probe, it is still performing well and is already conducting exciting scientific research. The door was designed to protect the detector before launch, but it failed to open as planned after multiple attempts. The gate blocks low-energy X-rays, effectively cutting off the mission at 1,700 electron volts, compared with the planned 300 electron volts. The XRISM team will continue to explore this anomaly and is working on different ways to open this door. Xtend instruments are not affected.

NASA's XRISM General Observing Facility at Goddard is accepting observation proposals from U.S. and Canadian agency members until Thursday, April 4. Cycle 1 of the XRISM general observer survey will begin in summer 2024.

XRISM is a collaborative mission between the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration (NASA), in which ESA is also involved. NASA's contribution includes scientific participation from the Canadian Space Agency.

Compiled source: ScitechDaily