Tiny Galaxy Andromeda XXXV Challenges Our Understanding of Cosmic Evolution and Survival

Astronomers have discovered the smallest and least luminous galaxy on record, situated roughly 3 million light-years from Earth. This finding poses a challenge to current understandings of galaxy formation, as such diminutive galaxies were presumed to have perished in the extreme heat and density of the early universe. Designated as Andromeda XXXV, this newly found galaxy is part of a collection of small satellite galaxies revolving around Andromeda. Researchers postulate that its existence might alter the comprehension of cosmic evolution and the factors that permitted small galaxies to survive.

Features of Andromeda XXXV

A study published in The Astrophysical Journal Letters reveals that Andromeda XXXV is considerably smaller than other known dwarf galaxies, spanning about 1,000 light-years across its largest axis. Researchers utilized data from various astronomical surveys and observations made by the Hubble Space Telescope to verify its presence. Reportedly, Eric Bell, a professor at the University of Michigan, characterized it as «a fully operational galaxy, yet about a millionth the volume of the Milky Way.» Scientists were amazed by its ability to maintain the essential conditions for star formation despite its diminutive size.

The Difficulty of Identifying Dwarf Galaxies

Although dwarf galaxies are prevalent, they can be hard to detect due to their faint luminosity. The Milky Way has numerous known satellite galaxies, but locating similar formations around Andromeda has proven to be difficult. Previously identified dwarf galaxies in that vicinity were larger and brighter, conforming to established models. Nevertheless, Andromeda XXXV stands out because of its extended duration of star formation. Lead researcher Marcos Arias noted that some galaxies of similar size in Andromeda formed stars as recently as 6 billion years ago, whereas most of the Milky Way’s satellite galaxies ceased star formation around 10 billion years ago.

The Consequences for Theories of Galaxy Formation

Researchers are exploring why Andromeda XXXV escaped the harsh conditions that affected other small galaxies. Bell noted that this era in the universe resembled «a vat of boiling oil,» which was thought to strip galaxies of the gas necessary for star formation. The endurance of Andromeda XXXV indicates that existing theories regarding galaxy formation and evolution may require reassessment. Ongoing research and future space missions could shed light on how galaxies akin to Andromeda XXXV managed to survive in spite of severe cosmic conditions.