NASA's Hubble space telescope finds dead galaxies

When anyone says galaxy, it brings to mind a pool of stars, planets and even existence of life. With various processes, explosions, star births, a notion of liveliness is associated with the word 'galaxy'. But when we say 'dead' galaxies. An unknown gloom sets in.

Using NASA's Hubble Space telescope and Atacama Large Millimeter/Submillimeter Array (ALMA), astronomers have found at least six, massive galaxies which were 'dead' at the time universe was 3 billion years old.

Cold Hydrogen is required to form new stars. These dead galaxies had run out of cold hydrogen. Since there was no fuel, the galaxies could not make new stars and thus, were 'empty'.

As per scientists, these galaxies being dead was a surprising thing as when the universe was 3 billion years old, there was a spurt of star formation. It was the 'peak epoch' of star formation.

NASA has said there is generally less likelihood of these galaxies rejuvenating even after minor mergers with nearby small galaxies.

Study of these dead galaxies has been published in the journal Nature.