83 supermassive black holes discovered, they're as big as sun
New Delhi : Sky watchers there is good news as astronomers have discovered 83 quasars powered by supermassive black holes 13 billion light-years away from the Earth.
"It is remarkable that such massive dense objects were able to form so soon after the Big Bang," said Michael Strauss, a professor at Princeton University in the US.
Scientists have discovered gigantic black holes at the centers of galaxies and can be millions or even billions of times more massive than the Sun.
A supermassive black holes becomes visible when gas accretes onto it, causing it to shine as a 'quasar.'
The finding, published in the Astrophysical Journal, increases the number of black holes known at that epoch considerably, and reveals, for the first time, how common they are early in the universe's history.
The finding provides new insight into the effect of black holes on the physical state of gas in the early universe in its first billion years.
Previous studies have been sensitive only to the very rare, most luminous quasars, and thus the most massive black holes.
The new discoveries probe the population of fainter quasars, powered by black holes with masses comparable to most black holes seen in the present-day universe.
Scientists can't directly observe black holes with telescopes that detect x-rays, light, or other forms of electromagnetic radiation.
Yet, they can infer the presence of black holes and study them by detecting their effect on other matter nearby. If a black hole passes through a cloud of interstellar matter, for example, it will draw matter inward in a process known as accretion.
A similar process can occur if a normal star passes close to a black hole. In this case, the black hole can tear the star apart as it pulls it toward itself. As the attracted matter accelerates and heats up, it emits x-rays that radiate into space.
Recent discoveries offer some tantalizing evidence that black holes have a dramatic influence on the neighborhood around them, emitting powerful gamma-ray bursts, devouring nearby stars, and spurring the growth of new stars in some areas while stalling it in others.
