This galaxy likley devoured its companions and is now lonelier than expected

Using data from NASA's Chandra X-ray Observatory and the International Gemini Observatory, astronomers have discovered a surprising solo galaxy that likely pulled in and absorbed its former companion galaxies and is now lonelier than expected.

Located about 9.2 billion light-years from Earth, the galaxy, named 3C 297, contains a quasar, a supermassive black hole pulling in gas at the centre of the galaxy and driving powerful jets of matter seen in radio waves. This discovery may push the limits for how quickly galaxies are expected to grow in the early Universe.

In the above composite image, data from NASA's Chandra is coloured purple while red and green represent VLA and Gemini data, respectively. It also includes visible light and infrared data from the Hubble Space Telescope, coloured blue and orange respectively.

If you're feeling lonely, remember that at least you're not 9.2 billion light-years from Earth and observed through X-ray data from @chandraxray!Galaxy 3C 297, is lonelier after it likely pulled in and absorbed its former companion galaxies.MORE>>> https://t.co/8BWXs62ZLq

— NASA Marshall (@NASA_Marshall) March 8, 2023

According to NASA's press release, the properties of 3C 297 resemble those of a galaxy cluster in various aspects, such as the presence of vast amounts of gas heated to millions of degrees, a signature feature of a galaxy cluster, as evidenced in the X-ray data from Chandra.

Additionally, the researchers observed a quasar jet that had been curved by its surroundings, as detected by the Karl G. Jansky Very Large Array, and the other quasar jet had created an X-ray "hotspot" by smashing into the surrounding gas, which is also a trait of a galaxy cluster. Nevertheless, the Gemini Observatory's data shows that there is only one galaxy in 3C 297.

Astronomers consider 3C 297 a "fossil group" rather than a galaxy cluster, which they define as a stage of the evolution of galaxies in which one galaxy attracts and merges with others. If this is the case, then this lonely galaxy would be the farthest fossil group ever discovered, the team says.

While the authors do not exclude the possibility of dwarf galaxies in the vicinity of 3C 297, their existence alone would not account for the absence of larger galaxies such as the Milky Way. Nearby examples like M87 in the Virgo Cluster have had significant galactic companions for billions of years. In comparison, 3C 297 is expected to be lonely for billions of years.