ALESS 073.1 is an old

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s away from Earth. The discovery was published in February 2021 in the journal ''

Science Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earli ...

''. It has challenged the way astronomers understand galaxies and

galaxy formation The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning, the formation of the first galaxies, the way galaxies change over time, and the processes that have gen ...

Observation

The galaxy was reported in a study conducted by a team of astronomers led by Dr. Federico Lelli at

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. The team used the Atacama Large Millimeter/submillimeter Array (ALMA) telescope, currently the largest radio telescope in the world, to observe the galaxy in its adolescence. The publication of the study of ALESS 073.1 includes “one of the sharpest, direct images of a primordial galaxy ever produced which allowed the team to undertake a detailed study of its internal structure," according to Cardiff University.

Distance

ALESS 073.1 is about 12 billion light years away from Earth. Due to its distance away from Earth, the light being shown is from when the universe was only 10% of its current age.

Characteristics

Like all galaxies, ALESS 073.1 is composed of gas, dark matter, and dust. It is made from stars that are held together by gravity. ALESS 073.1 is estimated to have formed 12 billion years ago, just 1.2 billion years after the Big Bang. The image of the galaxy seen now gives an image of it during its early years. However, the physical characteristics of the galaxy indicate that the galaxy is much older than its features indicate. ALESS 073.1 exhibits features normally attributed to mature galaxies, such as spiral arms that extend from its center. In this way, it has similar features to spiral galaxies. It also has a rotating disk and a bulge, characteristics found in mature galaxies. This is contrary to the previous understanding of newer galaxies being chaotic, without a particular shape or structure. Over billions of years, young galaxies slow down and stabilize. This creates the distinctive features that are associated with mature galaxies. The core of ALESS 073.1 hints at the presence of a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical obj ...

, since it is producing more energy than is typical for stars.

Scientific implications

The galaxy's young features, while displaying mature features, challenges scientists’ understanding of galaxy formation. However, more images and information are needed to indicate if this can be observed from other galaxies. The massive bulge of ALESS 073.1 also puts features typically associated with mature galaxies into question. A bulge is a group of stars that are clustered together at the center of the galaxy. Bulges were generally thought to be a prominent feature of mature galaxies. It was thought that these bulges formed slowly over a long period of time through the merging of smaller galaxies. However, the discovery of ALESS 073.1’s bulge indicates that they are able to be formed much quicker than previously thought. Approximately half of ALESS 073.1’s stars were found to be present in the bulge.

References

{{2021 in space Spiral galaxies Fornax (constellation) Stellar evolution Cardiff University Black holes Radio telescopes