Infrared observations from NIRCam and MIRI of the James Webb spacecraft reveal the secret of the Caleso Telega galaxy, the result of a space collision that gave it the shape of a ring.
One of the most recent observations of the James Webb Space Telega Telescope is about 500 million light years from us, in the constellation of Sculptor, this galaxy is a rare sight; its view, like a wheel, is the result of a particularly intense space event: the high-speed collision of the spiral galaxy and another smaller galaxy.
Other telescopes, including Hubble, have already seen Coleso Telega's galaxy, but the new infrared data from Webb goes beyond the amount of dust that covers the galaxy, including the unprecedented details of star formation in the galaxy and the central black hole, showing how the Coleso Telega galaxy has changed over billions of years.
The Telega wheel is a galaxy once wrapped in space dust, and is therefore mysterious to us. As a result of the collision of two galaxies, it has not only preserved much of its spiral character, but has also undergone enormous changes in its structure. The Coleso Telega galaxy has two rings: a bright internal ring and a coloured surrounding ring. These two rings are expanding outwards from the center of the collision. Because of these distinctive features, astronomers call it the "ring galaxy", a less common structure than spiral galaxies, such as our Milky Way.
The bright core contains a huge amount of hot dust, and in the more bright areas there are giant clusters of young stars. The outer ring, which has expanded for about 440 million years, is dominated by star formation and supernovas. When the ring expands, it sinks into surrounding gas and causes the formation of stars.
What can NIRCam Webb see in the infrared range?
Webb's high-precision tools allowed us to see the individual stars and the star-forming regions inside the Coleso Telega galaxy and to detect the behaviour of the black hole in its galaxy center. These new details provide a new understanding of the galaxy in the process of slow transformation.
The near infrared camera, Webba's main instrument, is monitoring near infrared between 0.6 and 5 microns, observing wave lengths that can show even more stars than those seen in visible light. This is due to the fact that young stars, many of them formed in the outer ring, are less visible because of the presence of dust when observed in infrared light. On the cover, the NIRCam data are painted blue, orange and yellow.
- Single stars and star-forming areas; the difference between distribution and the correct form of older star populations and dense dust in the core compared to the wrong forms associated with younger star populations outside.
The next video shows the Koleso Telega galaxy, seen by Webb's space telescope using NIRCam, which allows you to see details that are difficult to see on individual images.
What did MIRI see instead?
In order to get a closer look at the finer details of the dust in the galaxy, the MIRI instrument, which can be seen in the average infrared range, shows regions in the Coleso Telega galaxy, rich in hydrocarbons and other chemical compounds, as well as silicate dust, such as most of the dust on Earth. These areas form a series of spiral rays that essentially form a galaxy skeleton. The rays are seen in previous Hubble observations published in 2018, but become much more visible with Webb.
The following image is the result of data from the MIRI galaxy Koleso Telega without the addition of NIRCam. The medium infrared light shows the exact details of dusty areas and young stars in the galaxy. The latter, many of which are present in the lower right of the outer ring, cause the surrounding hydrocarbon dust to glow orange. The dust between the core and the outer ring that formed the "rays" that inspired the name of the galaxy consists mainly of silicate dust. A smaller spiral galaxy up to the left of the galaxy of Koleso Telega shows the same behavior and a large amount of star formation.
Webb's observations point out that Koleso Telega's galaxy is in a transition phase. The galaxy, which before the collision was supposed to be a normal spiral galaxy like the Milky Way, will continue to transform. While Webb gives us an idea of the current state of the Koleso Telega galaxy, it also gives us an idea of what happened to this galaxy in the past and how it will develop in the future.