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Using the Gaia telescope of the European Space Agency (ESA), an international team of astronomers discovered a huge "ghost" galaxy on the outskirts of the Milky Way.
Behind the disk of the Milky Way, Gaia saw a mbadive object with an extremely low density, named Antlia 2 (or Ant 2).
Ant 2 is known as a dwarf galaxy. But compared to other known dwarf satellites in our galaxy, Ant 2 is huge. It is as large as the Great Magellanic Cloud (LMC) and is one-third the size of the Milky Way itself, astronomers said.
It is also 10,000 times weaker in terms of light. In other words, it is either too big for its brightness, or too dark for its size.
"It's a galaxy ghost," principal author Gabriel Torrealba of the University of Cambridge said in a statement.
"Objects as diffuse as Ant 2 have simply not been seen before.Our discovery was only possible thanks to the quality of the Gaia data."
For the study, the team measured the spectrum of more than 100 red giant stars just before the movement of the Earth around the Sun made Ant 2 unobservable for months
which It allowed them to confirm that the ghostly object they had spotted was real: all the stars were moving together.
The # 2 never gets too close to the Milky Way, but stays at least 40 kiloparsecs (about 130,000 light years). The researchers were also able to obtain the mbad of the galaxy, much lower than expected for an object of this size.
"The simplest explanation of why Ant 2 seems to have so little mbad today is that it was dismantled by the galactic tides of the Milky Way," said co-author Sergey Koposov from Carnegie Mellon University, Pennsylvania, United States.
Although it is speculated that some dwarfs might be inflated by vigorous star formation, the team has not yet determined the exact process that allowed Ant2 to take such an extension.
Astronomers have explained that the solution of the Ant 2 puzzle might help researchers to understand how early structures of the early universe came into being and to discover other objects of this type, revealing how common these ghostly galaxies are. [19659002-IANS
/ mag / bg
(This story was not edited by Business Standard staff and is generated automatically from a syndicated feed.)
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