Free Astronomy Magazine July-August 2026

26 JULY-AUGUST 2026 ASTRO PUBLISHING or fall due to the source’s motion to- ward 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 stretching reveals the iron’s velocity. The researchers found that the wind is a little faster than expected. Combined with the high temperature, it’s powerful enough to produce the cool wind without cosmic rays, although they may still be contributing. The researchers calculate that the center of M82 expels enough gas every year to form seven stars with the mass of our Sun. This presents another puzzle. “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 T he 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. [NASA’s Goddard Space Flight Center, JAXA/NASA, XRISM Collaboration et al. 2026] of gas a year. But XRISM tells us much more gas is moving outward,” said co-author Edmund Hodges- Kluck, an astronomer and XRISM team member at NASA Goddard. “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.” The XRISM satellite’s observations of M82 will help improve models of starburst galaxies, which may help scientists answer these types of ques- tions in the future. NASA’s contribu- tions to international projects like XRISM are part of the agency’s ef- forts to innovate with ambitious sci- ence missions that will help us better understand how our cosmos works. “Some of our early models of star- burst galaxies were developed in the 1980s, and we’re finally able to test them in ways that weren’t possible before XRISM,” said co-author Sky- lar Grayson, a graduate student at Arizona State University in Tempe. “It provides opportunities to figure out why the model might not be capturing everything that’s going on in the real universe.” !