Scientists released the latest images of NASA’s triumphant James Webb Space Telescope. the most recent release documents the Cartwheel galaxy, which lies some 500 million light-years from our planet and is aptly named for its wheel-like appearance, complete with a central hub, tire, and even wavy fluorescent spokes. Webb also recorded two smaller companion galaxies next to Cartwheel.
The new images come on the heels of NASA’s presentation on July 12, five opening scenes captured by the Webb telescope, the most powerful space observatory built to date. Since they were released on December 2. On February 25, Webb’s 18 hexagonal golden mirrors have lined up to capture other targets in space, although not all images have been released. Snapshots have been included South Ring Nebularesembling a soap bubble expanding from a dead star, and the striking Carina nebulacomposed of swirling dust similar to jagged cliffs.
Astronomers have been studying the Cartwheel galaxy for decades. Initially, it was surveyed from two ground-based observatories in Australia, first the UK’s Schmidt telescope and then the Anglo-Australian telescope. But he is best known for hubble space telescopewhich images produced in the 1990s with more details of the composition of the galaxy. And just as the Webb, in July, revealed the presence of even more distant galaxies hiding from our sighthis Cartwheel photographs magnified the detailed star formation within the galaxy’s rings and the dozens of other star systems beyond.
Cartwheel’s appearance stems from a collision of two galaxies that occurred hundreds of millions of years ago. “We guess that Cartwheel probably started out looking like the Milky Way, and then this other galaxy moved on,” he said. marcia rieke, principal investigator of the near-infrared camera, or NIR camera, one of the science instruments on the Webb telescope. However, the smaller galaxy, instead of getting caught up in the great spiral it was entering, continued on, moving away from the larger one. It is not seen in the image that NASA published.
Galactic collisions are not uncommon in deep space, although it is rare that they result in a shape so perfect that it piques human curiosity. Kirk Borne, who was the principal investigator for the Hubble observation of Cartwheel but was not involved with Webb, said the galaxy’s strange shape, which formed by coincidence during the merger, has motivated astronomers to study it for decades.
Because a smaller galaxy collided with a larger one, and directly through its center, it was less disruptive to the shape of each galaxy, and both were relatively able to maintain their individuality. “What changed the shape of Cartwheel was the influence of the gravitational field of this other galaxy changing the orbits of the stars in the original Cartwheel galaxy,” said Dr. Rieke.
Dr. Borne, who has studied other galaxy collisions, described the smaller galaxy as a bullet that pierced the larger one. After observing the cosmic object in the 1990s, scientists noticed a trail of hydrogen gas following the smaller galaxy, which Dr. Borne called the “smoking gun” indicating that it had kept moving after create the new Cartwheel formation.
Cartwheel, already 1.5 times the size of the Milky Way, is still expanding and new stars are forming both within its outer ring and on its edge. However, there is no concrete answer as to how big Cartwheel will get, when it will stop growing, or what shape it will take when it does.
Cartwheel images were already in hand on July 12, although they were not available to the public until this week. have been filtered to make them more visually accessible, highlighting vivid blue-hued young stars and red-hued molecules of older stars and space dust floating between the rings. While it’s colorful, Joseph DePasquale, senior science imaging developer at the Space Telescope Science Institute, which manages the Webb and Hubble spacecraft, emphasized that stars and dust are actually detected as infrared light rather than colors.
New technology to detect that light in such detail is what distinguishes Webb’s images from those made by Hubble and the Anglo-Australian Telescope. While Hubble had some capabilities to record light in the infrared spectrum, Webbs are more advanced and create more vibrant images. The NIRCam, for example, which was built by about 25 people who worked with Dr. Rieke over 11 years, distinguishes between the infrared colors of stars, which are invisible to the human eye.
When Hubble captured Cartwheel in the 1990s, the galaxy’s “spokes” were obscured by clouds of light-scattering gas, making it difficult to see the thousands of stars forming within. Now, because Webb can study mid-infrared and near-infrared wavelengths of light, he can filter out space dust. That helps confirm some of the theories about Cartwheel’s composition that were formed using Hubble technology and uncover new information, such as the lack of star formation in some areas between the wheel’s spokes.
“I think the combination of the two telescopes, far from making one of them obsolete, actually only increases the benefits and power of Hubble because now we can make these comparisons,” Dr. Borne said.
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