Massive galaxies grow by eating stars in smaller neighbors
To further their expansion, largest galaxies in the universe no longer make up their own stars, but eat up stars of smaller, neighboring galaxies.
September 19, 2014
Researchers examined more than 22,000 galaxies and found that small galaxies differ from huge ones in the way stars are born. In small galaxies, stars are born from gas very efficiently. Huge galaxies, however, are not as effective in creating stars from gas. To grow, massive galaxies “eat-up” stars from small galaxies.
Dr Aaron Robotham, of the International Centre for Radio Astronomy Research (ICRAR), said: "All galaxies start off small and grow by collecting gas and quite efficiently turning it into stars. Then every now and then they get completely cannibalised by some much larger galaxy."
Published in Monthly Notices of the Royal Astronomical Society by Oxford University Press, the research led by Dr. Robotham, concludes that Milky Way is approaching the size when it will start incorporating stars from other smaller galaxies, rather than by creating stars from gas.