A large pink speckled galaxy resembling a wheel with a small inner oval, with dusty blue in the middle on the right, with two smaller spiral galaxies of the same size on the left on a black background. – NASA, ESA, CSA, STSCI
Aug. 2 () –
The James Webb Space Telescope has observed the chaos of the Cartwheel Galaxy, revealing new details about star formation and the galaxy’s central black hole.
Webb’s powerful infrared gaze produced this detailed image of Cartwheel and two smaller companion galaxies against a background of many other galaxies. This image provides a new view of how Cartwheel has changed over billions of years.
Located about 500 million light-years away in the Sculptor constellation, this galaxy is a rare sight. Its appearance, much like that of a cartwheel, is the result of an intense event: a high-speed collision between a large spiral galaxy and a smaller galaxy not seen in this image. Collisions of galactic proportions cause a cascade of different, smaller events between the galaxies involved; Cartwheel is no exception.
The collision most notably affected the shape and structure of the galaxy. Cartwheel sports 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. Because of these distinctive features, astronomers call it a “ring galaxy,” a less common structure than spiral galaxies like our Milky Way. reports NASA.
The bright core contains an enormous amount of hot dust, and the brightest areas are home to gigantic clusters of young stars. 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 collides with surrounding gas and triggers star formation.
Other telescopes, including the Hubble Space Telescope, have previously examined Cartwheel. But the spectacular galaxy has been shrouded in mystery, perhaps literally, given the amount of dust that obscures the view. Webb, with his ability to detect infrared light, now discovers new insights into the nature of the galaxy.
The Near Infrared Camera (NIRCam), Webb’s primary imager, peers into the near infrared range from 0.6 to 5 microns, seeing crucial wavelengths of light that can reveal even more stars than seen on Earth. visible light. This is because young stars, many of which are forming in the outer ring, they are less obscured by the presence of dust when viewed in infrared light.
In this image, the NIRCam data is colored blue, orange, and yellow. The galaxy shows many individual blue dots, which are individual stars or hotbeds of star formation. NIRCam also reveals the difference between the smooth distribution or shape of older star populations and the dense dust in the core by comparison. with the lumpy shapes associated with the younger star populations outside of it.
However, learning finer details about the galaxy’s inhabiting dust requires Webb’s Mid-Infrared Instrument (MIRI). MIRI data is colored red in this composite image.
It reveals interior regions rich in hydrocarbons and other chemical compounds, as well as silicate dust, like much of the dust on Earth. These regions form a series of spiral spokes that essentially form the skeleton of the galaxy. These radii are evident in earlier Hubble observations published in 2018, but they become much more prominent in this image of Webb.
Webb’s observations underscore that Cartwheel is in a very transitory stage. The galaxy, which was presumably a normal spiral galaxy like the Milky Way before its collision, will continue to transform. While Webb gives us a snapshot of the current state of this galaxy, it also provides information about what has happened to this galaxy in the past and how it will evolve in the future.
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