The James Webb Space Telescope has captured an image of the Cartwheel galaxy where its capricious shape leaves no one indifferent.
Every time the newly launched James Webb Space Telescope releases a new image, it causes excitement. This is the case with the new object he managed to capture. It’s about the Cartwheel galaxy and it’s full of history. But before we read your scars, let’s get our bearings. The Wheel Galaxy (also known as ESO 350-40 or PGC 2248) It is located over 500 million light-years in the direction of the constellation Sculptor. It is estimated to be about 150,000 light-years across, making it slightly larger than our Milky Way.
This galaxy does not correspond to a discovery. In fact, Hubble has already provided us with spectacular images that have allowed us to discover part of its history. However, its large amount of dust made it virtually invisible to the veteran telescope. Now, with Webb, the story we can read is much more complete, as its infrared energy can cut through that dust. It is as if we had deciphered pages of a book that were in another language. Thanks to that, we can now see how it evolved over the last billions of years, learning new details about the formation of stars in that galaxy and the black hole at its center.
NIRCAM AND MIRI, THE MANUFACTURERS OF THE IMAGE
One of the Webb images we owe thanks to the NIRCam instrument, the near-infrared camera, which can capture the sky in a range of wavelengths from 0.6 to 5.0 microns. Its shades of blue, orange and yellow reveal far more stars and structures than we can see in the human visible range. The distribution of the oldest stellar populations is also revealed, as well as the large concentration of dust in the core compared to other regions of the galaxy.
Another image of this galaxy is captured with the MIRI instrument, the camera that captures the universe in the mid-infrared range. The data is colored in pink tones that allow you to see regions rich in hydrocarbons and other compounds like silicates. In this band, the almost spiral rays that unite the center with the galactic periphery stand out above all.
Finally, the image that was most distributed by the official Webb image distribution channels was a composite between images captured with NIRCam and MIRI.
Image of the Cartwheel galaxy composed of data provided by Webb’s NIRCam and MIRI instruments || Credits: NASA, ESA, CSA, STScI, Webb ERO Production Team.
THIS IS THE CARTWHEEL GALAXY
Seeing what this galaxy looks like, the name “wagon wheel” seems obvious, right? However, its shape was not always like this, as this morphology is the result of a cataclysmic event: a high-speed collision between a spiral galaxy and a smaller one. This type of collision causes a kind of “transient dance” between the objects involved. What we see now is nothing more than an instant of that dance where the events that happened made us appreciate it in that characteristic way.
Perhaps the most obvious consequences we can see in this galaxy are the two rings it features. The inside is shown with a much more noticeable brightness than the outside, which, on the other hand, shows more colors and is more striking. These two structures have in common the fact that they are expanding from the center of the galaxy, which appears to be the epicenter of the collision. That is, the small galaxy crossed the large one in its central zone. Because of this, galaxies that look like this are called ring galaxies, which are less common than ellipticals like M87 or spirals like the Milky Way.
The center of the Cartwheel galaxy is populated by gigantic clusters of young stars, making it an area of great erosion due to the amount of radiation emitted by these young celestial objects. Regarding the outer ring, it is known that it has been expanding for about 440 million years and is a zone of birth and death. Stars are born there in smaller clusters than those at the center of the galaxy and also die in the form of supernovae.
What would this galaxy look like before it collided? Scientists believe it could have been a spiral galaxy like ours, but that’s just a hypothesis. What is clear is that the galactic dance continues and the galaxy will continue to change its appearance. Today, it looks like a somersault, but what will it be like billions of years from now?
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Antonio Pérez Verde is the author of the website astrometric. More texts here.