Study reveals satellite galaxies may have vanished from Milky Way

New Delhi, India Published: Nov 25, 2021, 10:06 PM(IST)

In an undated image from NASA, the center of the Milky Way, viewed by the Hubble space telescope. Photograph:( Twitter )

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The Milky Way began to form relatively soon after the Big Bang explosion that marked the beginning of the universe some 13.8 billion years ago

A new study has revealed that satellite galaxies may have vanished from the Milky Way.

The Milky Way began to form relatively soon after the Big Bang explosion that marked the beginning of the universe some 13.8 billion years ago. 

The sun, located roughly 26,000 light-years from the supermassive black hole residing at the center of the galaxy, formed about 4.5 billion years ago.

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Subsequent galactic mergers were instrumental in configuring galaxies existing now.

Gaia satellite, operated by the European Space Agency, has conducted a new analysis which shows most of the galaxies in the Milky Way are actually relatively new to the area.

The study, led by astrophysicist François Hammer of the Paris Observatory in France, has been published in The Astrophysical Journal.

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''We conclude that due to their unequaled high energies and angular momenta, most dwarfs cannot be long-lived satellites, and if they could be bound to the Milky Way, they are at first passage, i.e., infalling less than 2 billion years ago,'' he said. 

Sagittarius, a ''dwarf'' galaxy 10,000 times less massive than the Milky Way, has passed twice through our galaxy’s immense disk containing most of its roughly 100 billion stars.

Until now, the understanding of the galaxy’s shape had been based upon indirect measurements of celestial landmarks within the Milky Way and inferences from structures observed in other galaxies populating the universe.

''The Milky Way is a big galaxy, so its tidal force is simply gigantic and it's very easy to destroy a dwarf galaxy after maybe one or two passages,'' Hammer said.
 

(With inputs from agencies)

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