NASA, ESA and the Canadian space agency CSA have published a new photo from the James Webb Space Telescope. It is a composite image of the separate Cartwheel galaxy, which is located about 500 million light-years from Earth.
The cartwheel system was according to the space agencies until now always a bit shrouded in mystery by the large amounts of dust. Hubble has previously also looked at this galaxy, but the ‘spokes’ in the wheel, for example, are much more visible in the new image. Hubble is therefore much less specialized than James Webb in the infrared part of the spectrum and that specific capacity is needed to see through dust. The various instruments of the James Webb telescope reveal a number of things. For example, individual stars and star-forming regions in the galaxy can be seen and the behavior of a black hole can be seen in the center.
The image is a composite, a compilation of data from the Near-Infrared Camera (NIRCam) and the Mid-Infrared Instrument (MIRI). NIRcam is the primary camera for the 0.6 to 5μm area. MIRI is an instrument cooled to -266 degrees Celsius that consists of a camera and a spectrograph and focuses on the range from 4.9 to 28.8μm. This instrument can see through dust clouds much better than NIRcam.
The data from only NIRCam (left) and the data from MIRI
In the image below, the NIRCam data is colored blue, orange and yellow. The necessary individual blue dots are visible; these are stars or areas in which stars form. NIRCam also helps scientists understand the difference between the shape of the older star populations and the dense dust clouds in the core compared to the lumpy shapes outside that are associated with younger star populations. The MIRI data is marked in red. This provides insight into the regions that are rich in hydrocarbons and other chemical compounds.
James Webb’s data once again makes it clear that the Cartwheel system is in a transitional phase. It was probably once a normal galaxy like the Milky Way, but in the past there was a high-speed collision between a large spiral galaxy and a small galaxy that is not visible in the image. The impact changed its shape and structure; there are two rings and astronomers call it a ring galaxy. More than two weeks ago, the space agencies published the first five images of James Webb.