Webb’s instruments reveal new details about star formation

The incredible imaging capabilities of NASA’s James Webb Space Telescope have revealed the Cartwheel Galaxy, a rare ring galaxy once shrouded in dust and mystery. Formed as a result of a collision between a large spiral galaxy and another smaller one, the galaxy has not only largely retained its spiral character, but has also experienced massive changes throughout its structure. Webb’s high-precision instruments analyze individual stars and star-forming regions within the Cartwheel. They also revealed the behavior of the black hole inside its galactic center. These new details provide a renewed understanding of a galaxy in the midst of a slow transformation. This image from Webb’s Mid-Infrared Instrument (MIRI) shows a group of galaxies, including a large distorted ring-shaped galaxy known as the Cartwheel. The Cartwheel Galaxy, located 500 million light-years away in the constellation Sculptor, consists of a bright inner ring and an active outer ring. While this outer ring has a lot of star formation, the dusty region in between reveals many stars and star clusters. The mid-infrared light captured by MIRI reveals fine details about these dusty regions and young stars in the Cartwheel Galaxy, which are rich in hydrocarbons and other chemical compounds, as well as siliceous dust, like much of the dust on Earth. Credit: NASA, ESA, CSA, STScI, Webb ERO Production Team

Webb records stellar gymnastics in the Cartwheel galaxy

Peering into the chaos of the Cartwheel Galaxy, NASA’s James Webb Space Telescope is revealing new details about star formation and the galaxy’s central black hole. Webb’s powerful infrared vision produced this detailed image of Cartwheel and two smaller companion galaxies against a backdrop of many other galaxies. This new view exposes how the Cartwheel Galaxy has changed over billions of years. Located about 500 million light-years away in the constellation Sculptor, the Cartwheel Galaxy is a rare sight. Its wagon wheel-like appearance is the result of an intense event – ​​a high-speed collision between a large spiral galaxy and a smaller one, which is not visible in this image. Collisions of galactic proportions cause a cascade of different, smaller events between the galaxies involved, and the Cartwheel is no exception. The collision most affected the shape and structure of the galaxy. The Cartwheel Galaxy has two rings — a bright inner ring and a surrounding, colorful ring. These two rings expand outward from the center of the collision, like ripples in a pond after a stone is thrown into it. Because of these distinctive features, astronomers call it a “ring galaxy,” a structure less common than spiral galaxies like our Milky Way. The bright core contains a huge amount of hot dust with the brightest regions being home to giant young star clusters. On the other hand, the outer ring, which has been expanding for about 440 million years, is dominated by star formation and supernovae. As this ring expands, it plows into the surrounding gas and triggers star formation. Other telescopes, including the Hubble Space Telescope, have previously looked at Cartwheel. But the dramatic galaxy has been shrouded in mystery – perhaps literally, given the amount of dust obscuring the view. Webb, with its ability to detect infrared light, is now revealing new insights into the nature of the Cartwheel. The Near-Infrared Camera (NIRCam), Webb’s primary imager, looks in the near-infrared region from 0.6 to 5 microns, seeing critical wavelengths of light that can reveal even more stars than those seen in visible light. This is because young stars, many of which form in the outer ring, are less obscured by the presence of dust when viewed in infrared light. In this image, the NIRCam data are colored blue, orange, and yellow. The galaxy shows many individual blue dots, which are individual stars or pockets of star formation. NIRCam also reveals the difference between the smooth distribution or shape of the oldest star populations and the dense dust in the core compared to the lumpy shapes associated with the younger star populations outside it. This is an image of the Cartwheel Galaxy taken with the NASA/ESA (European Space Agency) Hubble Space Telescope. Credit: ESA/Hubble & NASA However, learning finer details about the dust that inhabits the galaxy requires Webb’s Mid-Infrared Instrument (MIRI). The MIRI data are colored red in this composite image. It reveals regions within the Cartwheel Galaxy rich in hydrocarbons and other chemical compounds, as well as siliceous dust, like much of the dust on Earth. These regions form a series of spiral rays that essentially form the skeleton of the galaxy. These rays are evident in previous Hubble observations released in 2018, but they become much more apparent in this Webb image. Webb’s remarks underscore that Cartwheel is in a very transitional stage. The galaxy, which was probably a normal spiral galaxy like the Milky Way before its collision, will continue to transform. While Webb gives us a snapshot of Cartwheel’s current state, he also provides insight into what has happened to this galaxy in the past and how it will evolve in the future. The James Webb Space Telescope is the world’s leading space science observatory. Webb will solve mysteries in our solar system, look beyond distant worlds around other stars, and explore 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 the Canadian Space Agency.