Saturday, 3 April 2021

QUASARS (QUASI STELLAR RADIO SOURCES)-BRIGHTEST OBJECTS IN THE UNIVERSE.

Quasars are the brightest objects known to us in the Universe. A single Quasar outshines an entire galaxy like the Milky Way by 10 to 100,000 times.

We consider our Sun as the most powerful, but the Sun is an average star in the Milky Way Galaxy. Milky Way consists of 100,000 crore stars like the sun, and the collective energy emitted by it is enormous. How a single Quasar out shines such enormous collection of stars is puzzling. 

Astronomers postulate that to emit such massive amounts of energy, all the Quasars must have super massive black holes in their center. The black holes at the center of Qasars have millions or even billion times our Suns mass. 

We know how black holes come into being, but no one knows how these super massive black holes in the center of the Quasars came about, and research on that is on. These black holes have to be much more massive than any of the ordinary black holes known to us, and astronomers and scientists do not have any theoretical explanation as to how they formed.  

If the brightest Quasar visible from earth,  3c273 is brought to a distance of some 30 light years away from the earth, then it would shine as bright as the Sun.  That Quasar is 4 trillion (4 lac crore) times as luminous as our Sun. A study had found evidence of Molecular Oxygen in this Quasar and it is for the first time that Oxygen had been found outside the Milky Way.

There are only about 2000 Quasars known to us of which the nearest to us is Markarian 231  which is about 600 million light years away. The farthest Quasar known to us is ULAS J1120 which is about 12.9 billion light years away. That means we are seeing the Quasar as it was 12.9 billion years ago very near to the time of Big Bang which happened 13.8 billion years ago.

At the rate Quasars shine and use up all the surrounding matter and convert into energy, they would have consumed all the matter and would be dead a long time ago. Therefore, it is likely that the Universe is currently devoid of any Quasar.

 

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