A recent news reported the existence of a red, dead galaxy in the early universe which us gaining mass at an enormously fast rate.
The galaxy was seen when universe was only 1.65 billion years in age. But it weighed thrice as much as milky way.
But the astronomers are jumbled up knowing how it gained so much mass in just a billion years.
The astronomers used the Keck Observatory in Hawaii to study the spectrum of the galaxy, called ZF-COSMOS-20115. The data confirmed that the galaxy did, in fact, exist in the early universe and revealed that it had stopped making stars 500 million to a billion years before its age which was observed. The data also indicate that the galaxy created the mass of more than a 1,000 suns each year. However even the most massive
galaxies at that time generated a mass of less than 100 suns annually. But with such a rapid star formation rate, the galaxy probably grew to its monster mass in less than 100 million years, the researchers say.
With an assumption we can say that the galaxy got so massive by colliding and merging with another galaxy. During such conditions it can stir up and compress gas to high densities, which can trigger intense star formation. But the events are typically short bursts, lasting less than 100 million years, when compared with the typical billion-year timescales for star formation in normal galaxies of the universe. However in these galaxies, gas gets consumed quickly because stars are forming faster than usual rates. If the galaxy runs out of gas, star formation stops.
Such monster galaxies should be rare because galaxies form as matter pools together and collapses due to gravity over cosmic time.
However earlier study suggests that its possible that ZF-COSMOS-20115 may not be the only candidate in the race and there could be more such galaxies hidden which are still to be found.
Similar studies of the other galaxies’ spectra could confirm if all of those candidates are inactive, too. If so, astronomers will have to figure out how larger numbers of deep gravity wells could develop to allow lots of galaxies to grow, merge and become red and dead just a billion years after the Big Bang, 13.8 billion years ago.
“The team has found an extreme galaxy, which is exciting,” says Peter Behroozi of the University of California, Berkeley, who was not involved in the study. The data offers evidence for a population of inactive galaxies in the early universe, which are extremely difficult to be observed.
Whatever be the point, one thing is clear that this galaxy is eating up mass like a hungry monster and it may one day become the most massive galaxy of our universe along with some of his colleagues.
Image source :
https://www.google.co.in/search?q=red+galaxy+massive&prmd=ivsn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj9qLnfi6PTAhWFrY8KHU1SBksQ_AUIBygB#imgrc=2D-q5l0_wp7seM:
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