NASA’s Webb Rounds Out Picture of Sombrero Galaxy’s Disk - UNIVERSE

After capturing an image of the iconic Sombrero galaxy at mid-infrared wavelengths in late 2024, NASA’s James Webb Space Telescope has now followed up with an observation in the near-infrared. In the newest image, the Sombrero galaxy’s huge bulge, the tightly packed group of stars at the galaxy’s center, is illuminated, while the dust in the outer edges of the disk blocks some stellar light.

Image A: Sombrero Galaxy (NIRCam)

NASA’s James Webb Space Telescope’s new image of the famous Sombrero galaxy in near-infrared wavelengths shows dust from the outer ring blocking stellar light from the inner portions of the galaxy.

NASA, ESA, CSA, STScI

Studying galaxies like the Sombrero at different wavelengths, including the near-infrared and mid-infrared with Webb, as well as the visible with NASA’s Hubble Space Telescope, helps astronomers understand how this complex system of stars, dust, and gas formed and evolved, along with the interplay of that material.

When compared to Hubble’s visible light image, the dust disk doesn’t look as pronounced in the new near-infrared image from Webb’s NIRCam (Near-Infrared Camera) instrument. That’s because the longer, redder wavelengths of infrared light emitted by stars slip past dust more easily, so less of that stellar light is blocked. In the mid-infrared image, we actually see that dust glow.

Image B: Sombrero Galaxy (NIRCam/MIRI)

The Sombrero galaxy is split diagonally in this image: near-infrared observations from NASA’s James Webb Space Telescope are at the left, and mid-infrared observations from Webb are at the right.

NASA, ESA, CSA, STScI

The Sombrero galaxy is located about 30 million light-years away from Earth at the edge of the Virgo galaxy cluster, and has a mass equal to about 800 billion Suns. This galaxy sits “edge on” to us, meaning we see it from its side.

Studies have indicated that hiding behind the galaxy’s smooth dust lane and calming glow is a turbulent past. A few oddities discovered over the years have hinted this galaxy was once part of a violent merger with at least one other galaxy.

The Sombrero is home to roughly 2,000 globular clusters, or collections of hundreds of thousands of old stars held together by gravity. Spectroscopic studies have shown the stars within these globular clusters are unexpectedly different from one another.

Stars that form around the same time from the same material should have similar chemical ‘fingerprints’ – for example, the same amounts of elements like oxygen or neon. However, this galaxy’s globular clusters show noticeable variation. A merger of different galaxies over billions of years would explain this difference.

Another piece of evidence supporting this merger theory is the warped appearance of the galaxy’s inner disk.

While our view is classified as “edge on,” we’re actually seeing this nearly edge on. Our view six degrees off the galaxy’s equator means we don’t see it directly from the side, but a little bit from above. From this view, the inner disk appears tilted inward, like the beginning of a funnel, instead of flat.

Video A: Sombrero Galaxy Fade (Visible, Near-Infrared, Mid-Infrared) 

This video compares images of the Sombrero galaxy, also known as Messier 104 (M104). The first image shows visible light observed by the Hubble Space Telescope’s Advanced Camera for Surveys. The second is in near-infrared light and shows NASA’s Webb Space Telescope’s look at the galaxy using NIRCam (Near-Infrared Instrument). The final image shows mid-infrared light observed by Webb’s MIRI (Mid-Infrared Instrument).
Credit: NASA, ESA, CSA, STScI

The powerful resolution of Webb’s NIRCam also allows us to resolve individual stars outside of, but not necessarily at the same distance as, the galaxy, some of which appear red. These are called red giants, which are cooler stars, but their large surface area causes them to glow brightly in this image. These red giants also are detected in the mid-infrared, while the smaller, bluer stars in the near-infrared “disappear” in the longer wavelengths.

Also in the NIRCam image, galaxies of diverse shapes and colors are scattered throughout the backdrop of space. The variety of their colors provides astronomers with clues about their characteristics, such as their distance from Earth.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

To learn more about Webb, visit: https://science.nasa.gov/webb  

Source: NASA’s Webb Rounds Out Picture of Sombrero Galaxy’s Disk - NASA Science