'Little Cub' galaxy may unlock secrets of early universe

Publish | 05 Jul 2017, 15:42

Online Desk

Astronomers have spotted a primitive galaxy called 'Little Cub' - located 50 million light years away from the Earth - which could unveil secrets of the universe just minutes after the Big Bang.

The Little Cub galaxy - which sits in the Ursa Major or Great Bear constellation - is being stripped of the gas needed to continue forming stars by its larger companion.

As the Little Cub has remained almost pristine since its formation, scientists also hope its elements will reveal more about the chemical signature of the early universe just minutes after its birth.

The Little Cub and its larger neighbour, a grand design spiral galaxy called NGC 3359, are about 200 to 300 thousand light years apart, and approximately 50 million light years from Earth, researchers said.

Gas from the Little Cub is being stripped away by its interaction with NGC 3359, which has up to 10,000 times as many stars as the Little Cub and is similar to our Milky Way.

“We may be witnessing the quenching of a near-pristine galaxy as it makes its first passage about a Milky Way-like galaxy,” said Tiffany Hsyu, a graduate student at University of California Santa Cruz in the US.

“It is rare for such a tiny galaxy to still contain gas and be forming stars when it is in close proximity to a much larger galaxy so this is a great opportunity to see just how this process works,” Hsyu said.

Essentially the larger galaxy is removing the fuel that the Little Cub needs to form stars, which will eventually shut down star formation and lead to the smaller galaxy's demise, researchers said.

The team also hopes to gain an insight into the make-up of the very early Universe, by studying the hydrogen and helium atoms that are being illuminated by the small number of very bright stars within the Little Cub - which also has the less romantic name SDSS J1044+6306.

Since this galaxy is so primitive, it may still preserve the hydrogen and helium atoms that were created minutes after the Big Bang.

“We know by studying the chemistry of the Little Cub that it is one of the most primitive objects currently known in our cosmic neighbourhood,” said Ryan Cooke from Durham University in the UK.

“Such galaxies, which have remained dormant for most of their lives, are believed to contain the chemical elements forged a few minutes after the Big Bang,” Cooke said.

The study appears in the Astrophysical Journal Letters.

Source: pti