XRISM Telescope Captures Hot Wind in Galaxy M82

Astronomers directly measure the speed of superheated gas billowing from the center of the nearby starburst galaxy.

Mar. 26, 2026 at 4:38am

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For the first time, astronomers have directly measured the speed of superheated gas billowing from a cauldron of stellar activity at the heart of M82, a nearby galaxy undergoing an extraordinary burst of star formation. The material is moving more than 2 million miles (over 3 million kilometers) per hour and appears to be the primary force driving a cooler, well-studied, galaxy-scale wind.

Why it matters

The classic model of starburst galaxies like M82 suggests that shock waves from star formation and supernovae near the center heat gas, kick-starting a powerful wind. Prior to XRISM, researchers didn't have the ability to measure the velocities needed to test that hypothesis, but now they see the gas moving even faster than some models predict, more than enough to drive the wind all the way to the edge of the galaxy.

The details

Researchers made the calculations using data from the Resolve instrument aboard the XRISM (X-ray Imaging and Spectroscopy Mission) spacecraft. The amount of X-ray light from iron and other elements told them the temperature - right within predictions at 45 million degrees Fahrenheit (25 million degrees Celsius). The heat exerts pressure on the gas and pushes it outward, forming the wind. The broadness of iron spectral lines conveyed the hot wind's speed through Doppler shifting.

  • The XRISM satellite's observations of M82 were made in 2026.

The players

Erin Boettcher

An astrophysicist at the University of Maryland, College Park and NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Edmund Hodges-Kluck

An astronomer and XRISM team member at NASA Goddard.

Skylar Grayson

A graduate student at Arizona State University in Tempe.

XRISM (X-ray Imaging and Spectroscopy Mission)

A spacecraft mission led by JAXA (Japan Aerospace Exploration Agency) in collaboration with NASA, along with contributions from ESA (European Space Agency).

M82

Also known as the Cigar galaxy, M82 is a nearby starburst galaxy located 12 million light-years away in the northern constellation Ursa Major.

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What they’re saying

“The classic model of starburst galaxies like M82 suggests that shock waves from star formation and supernovae near the center heat gas, kick-starting a powerful wind. Prior to XRISM, though, we didn't have the ability to measure the velocities needed to test that hypothesis. Now we see the gas moving even faster than some models predict, more than enough to drive the wind all the way to the edge of the galaxy.”

— Erin Boettcher, astrophysicist

“If the wind blows steadily at the speed we've measured, then we think it can power the larger, cooler wind by driving out four solar masses of gas a year. But XRISM tells us much more gas is moving outward. Where do the three extra solar masses go? Do they escape out of the galaxy as hot gas some other way? We don't know.”

— Edmund Hodges-Kluck, astronomer and XRISM team member

“Some of our early models of starburst galaxies were developed in the 1980s, and we're finally able to test them in ways that weren't possible before XRISM. It provides opportunities to figure out why the model might not be capturing everything that's going on in the real universe.”

— Skylar Grayson, graduate student

What’s next

The researchers plan to continue studying the XRISM data on M82 to better understand the complex dynamics of the galaxy's central wind and how it interacts with the larger-scale galactic outflow.

The takeaway

The XRISM satellite's observations of the starburst galaxy M82 have provided the first direct measurements of the speed of the superheated gas at the galaxy's center, revealing that it is moving faster than expected and is the primary driver of the galaxy-scale wind. This new data will help improve models of starburst galaxies and shed light on the complex processes shaping these dynamic systems.