XRISM Clocks Hot Wind of Galaxy M82

The Resolve instrument aboard the XRISM (X-ray Imaging and Spectroscopy Mission) spacecraft captured data revealing the velocity of the hot wind at the center of starburst galaxy M82. The energy range of iron emission lines show that the gas moves around 2 million miles (about 3 million kilometers) per hour. Inset: XRISM Xtend instrument’s image of M82.

Credit: NASA’s Goddard Space Flight Center, JAXA/NASA, XRISM Collaboration et al. 2026

Alt text: Spectrum and image of galaxy M82

Image description: This image is labeled, “XRISM Resolve Measures the Hot Wind of Starburst Galaxy M82.” It shows a graph where the bottom is labeled, “X-ray energy (keV),” with a range from 2 to 9. The left side is labeled “X-ray brightness.” A squiggly white line starts near the bottom of the left side. Several peaks are labeled, including silicon, sulfur, argon, and calcium. Four peaks are identified as iron. In the upper right corner, a small inset shows an image that looks like a purple pansy with a yellow center.

The Xtend instrument aboard XRISM captured this image of M82.

Credit: NASA’s Goddard Space Flight Center, JAXA/NASA, XRISM Collaboration et al. 2026

Alt text: Image of galaxy M82

Image description: In this X-ray image, the M82 galaxy looks like a purple pansy with a yellow center. Two black lines run through the top and bottom of the pansy.

The cool wind of galaxy M82 drives gas and dust up to 40,000 light-years from its core, as shown here using data from NASA’s Chandra X-ray Observatory and Hubble and Spitzer space telescopes. The inset shows a Chandra view of the galaxy’s central region, where a cauldron of stellar activity kick-starts the larger-scale outflow.

Credit: NASA’s Goddard Space Flight Center; X-ray: NASA/CXC/JHU/D.Strickland; Optical: NASA/ESA/STScI/AURA/The Hubble Heritage Team; Infrared: NASA/JPL-Caltech/Univ. of AZ/C. Engelbracht; XRISM Collaboration et al. 2026

Alt text: Chandra, Hubble, and Spitzer image of M82 with Chandra inset

Image description: This image shows observations from NASA’s Chandra, Hubble, and Spitzer missions of the starburst galaxy M82. An angled disk, green at the edges and yellowish white toward the center, shows the plane of the galaxy. Extending above and below are clouds of purple and red. An inset, pointing towards the galactic center, shows a yellow-orange blob surrounding by swirling purple. It’s labeled, “Chandra X-ray.” The larger image is labeled, “Chandra/Hubble/Spitzer X-ray/Optical/Infrared.”

Unlabeled version of the above

Credit: NASA’s Goddard Space Flight Center; X-ray: NASA/CXC/JHU/D.Strickland; Optical: NASA/ESA/STScI/AURA/The Hubble Heritage Team; Infrared: NASA/JPL-Caltech/Univ. of AZ/C. Engelbracht; XRISM Collaboration et al. 2026

Alt text: Chandra, Hubble, and Spitzer image of M82 with Chandra inset

Image description: This image shows observations from NASA’s Chandra, Hubble, and Spitzer missions of the starburst galaxy M82. An angled disk, green at the edges and yellowish white toward the center, shows the plane of the galaxy. Extending above and below are clouds of purple and red. And inset, pointing towards the galactic center, shows a yellow-orange blob surrounding by swirling purple.

Unlabeled version of the above, without inset. Find more versions and information about M82 at science.nasa.gov

Credit: NASA’s Goddard Space Flight Center; X-ray: NASA/CXC/JHU/D.Strickland; Optical: NASA/ESA/STScI/AURA/The Hubble Heritage Team

Alt text: Chandra, Hubble, and Spitzer image of M82

Image description: This image shows observations from NASA’s Chandra, Hubble, and Spitzer missions of the starburst galaxy M82. An angled disk, green at the edges and yellowish white toward the center, shows the plane of the galaxy. Extending above and below are clouds of purple and red.

This Chandra image shows M82’s central region, where a cauldron of stellar activity kick-starts the larger-scale outflow.

Credit: NASA/CXC/JHU/XRISM Collaboration et al. 2026

Alt text: Chandra image of M82

Image description: This X-ray image has a bright yellow blob with an orange outline at the center. Several other yellow-orange dots are scattered across the image. Bright purple surrounds the central blob, gradually getting darker toward the edge of the image.

This animation shows the difference between iron-25’s spectral line in a laboratory setting compared to XRISM’s observations from the center of M82. The M82 line is broader than the lab version due to Doppler shifting, which is the same phenomenon that causes the pitch of a sound to rise or fall due to the source’s motion toward or away from you. In the case of M82, the hot material near the center flies quickly in both directions, stretching out the iron’s spectral line. The amount of stretch tells scientists the iron’s velocity.

Credit: NASA’s Goddard Space Flight Center, JAXA/NASA, XRISM Collaboration et al. 2026

Alt text: Animation of iron spectral broadening

Image description: This animation begins on a graph of a white line against a background of swirling purple, green, and yellow — an image of the central part of M82. The white line has several jagged peaks in the middle and is labeled, “Iron-25 line/Lab reference.” The horizontal and vertical axes are labeled “X-ray energy” and “X-ray brightness,” respectively. After a moment, the graph blurs and shifts, broadening so that the jagged peaks turn into one larger curve with a small dip at the top. The line label changes to “Iron-25 line/M82 observed.” The graph shifts back and forth one more time before ending.

On Earth, M82’s hot winds would sweep across the entire United States in just 5 seconds, as shown in this animation.

Credit: NASA’s Goddard Space Flight Center

Alt text: GIF of M82’s wind speed

Image description: Yellow arrows move west to east over a purple map of the United States in this looping GIF. In the bottom-left corner is a stopwatch, also in shades of purple, showing that it takes an arrow 5 seconds to move across the map. The top of the animation has blue text that says, “If M82’s winds were on Earth …”

This image of M82, captured by the Near-Infrared Camera aboard NASA’s James Webb Space Telescope, shows the center of the galaxy in such detail that astronomers can distinguish small bright sources that are either individual stars or star clusters.

Credit: NASA, ESA, CSA, STScI, Alberto Bolatto (UMD)

Alt text: Webb image of M82

Image description: This infrared image shows a section of the M82 as imaged by NASA's Webb telescope. The galaxy is seen edge-on, tilted at a 45-degree angle. It has a bright line of yellowish white glowing at its core and dark brown tendrils of dust stretch along its length. Many white dots of various sizes — stars or star clusters — are scattered throughout the image but are most heavily concentrated toward the center. The whole galaxy is set against the black backdrop of space.