Irregular galaxy “NGC 6822” imaged by the European Space Agency’s Euclid Space Telescope | sorae satellite portal website

This is NGC 6822, an irregular galaxy located about 1.6 million light-years away in the constellation Sagittarius. Irregular galaxies are said to lack the distinct structures found in spiral galaxies, such as a star center, spiral arms, and a rotationally symmetric disk.

NGC 6822 belongs to the same group of galaxies as the Milky Way, called the Local Group, and was discovered by American astronomer Edward Emerson Barnard in 1884. It is also called the “Barnard Galaxy” because of this phenomenon.

This image was created based on data acquired by the European Space Agency’s (ESA) Visible Light Observer (VIS) and Near-Infrared Spectrophotometer (NISP) and Euclid Space Telescopes. Euclid observes not only visible light, but also infrared wavelengths that cannot be detected by the human eye, so images are colored according to the wavelength at the time of data acquisition.(About 700 nm is colored blue, about 1.1 µm is colored green, and about 1.7 µm is colored red).

The Euclid Space Telescope, which was launched in July 2023, was developed to explore the secrets of dark energy and dark matter. Based on observational data from Euclid, which aims to image billions of galaxies, we will create a 3D map of galaxies distributed along the large-scale structure of the universe, which are thought to be shaped by dark matter. It is also expected to deepen our understanding of dark energy, which is thought to accelerate the expansion of the universe.

[▲ صورة مكبرة لجزء من المجرة غير المنتظمة NGC 6822 مأخوذة بواسطة تلسكوب إقليدس الفضائي (مصدر الصورة: ESA/Euclid/Euclid Consortium/NASA، معالجة الصور بواسطة J.-C. Cuillandre (CEA Paris) -Saclay)، G. Anselmi )]

When the universe was early, it is believed that there was only hydrogen, helium, and a small percentage of lithium. Most elements heavier than helium, collectively referred to as “metals” in astronomy, are produced by nuclear fusion reactions inside stars and then expelled outward, or are produced as a result of violent phenomena such as supernova explosions caused by massive stars. It is believed that, in other words, the amount of metal in the universe increased as the generations of stars changed.

However, not all galaxies contain the same amount of metal. According to the European Space Agency, NGC 6822 has low metallicity and is an interesting object near the Milky Way to understand star formation and dust evolution in the early universe, so it was recently named the James Webb Space Telescope. Observations have also been made with the JWST. ). This observation by the Euclid Space Telescope not only revealed a number of purple-tinted star formation regions in the image, but also several globular clusters that provide clues to understanding how galaxies form, meaning they were captured.

Related article: Countless stars shine in a galaxy 1.5 million light-years away The irregular dwarf galaxy “NGC 6822” observed by the Webb Space Telescope (October 17, 2023)

An image of NGC 6822 taken by the Euclid Space Telescope was published by the European Space Agency on November 7, 2023 as one of the first full-color images from the Euclid mission.

source

• European Space Agency – Euclid’s view of the irregular galaxy NGC 6822

Text Editing/Syrian Studies Department