Quasars: Crucial to Give Birth to Live?
The Universe is a restless place beaming with all sorts of activity. Stars continue to Burn immense amount of gas to give rise to extreme luminosities, Neutron Stars and Pulsars blowing out intense radiation from sizes smaller than a city, Black Holes merging each other, and Supernovae ejecting radiation at such a high rate that surpasses the entire galaxy’s luminosity for a while. Yet, nothing is as awesome as Quasars. They outshine the luminosity of several galaxies combined, radiate from a region smaller than the solar system, and harbors Galaxies weighing millions to billions the mass of the sun.
The history of the discovery of Quasars dates back to 1968 when a pair of antennae detected a ‘Radio Blob’ from an unknown region of the sky. The resolution of the antennae was too poor to pinpoint the location of that Source. However, in 1969, when the moon passed in front of the radiation blob, the flux from the source decreased instantly. Astronomers measured the exact time and confirmed that the radio source was coming from a bluish star-like object. Soon, its spectrograph was taken which looked nothing like that of a star:
Due to its stunning radio source, it was soon named Quasi Stellar Radio Object or QUASARS for short. In order to explain this weird spectrum, physicists tried to describe in many ways which ranged from a strong radio source coming somewhere from the milky-way or an advanced alien civilization trying to connect with us. However, within the following decades, it was clear that such immense radiation was only possible if it was immensely far away and had a luminosity of several galaxies compacted to a size smaller than the solar system!
By the 80s, scientists were converging to the most amazing of the solutions. The Quasars harbor black holes weighing millions to billions of times the mass of the sun. In fact, almost every regular galaxy has a black hole of this mass range at its core. These black holes have enormous gravitational strength which allows a huge amount of gas to swirl around it. The gases quickly increase their velocities and form a disk-like structure around a black hole known as an Accretion disk. As, some of the gas plume down inside the event horizon, the kinetic energy is converted into heat. This heat is released in the form of Radio Waves. In fact, these radio waves are so powerful that they can be seen from far ends of the universe! At times, these waves form column-like structure at the poles at radiate blasts of energy which are known as synchrotron radiation.
Objects, so powerful must have had a heavy impact on the early universe. We can presumably be sure that they’re components of the early universe because the 3c273 is the nearest Quasar ever detected and it itself is situated at a distance of roughly 2 billion light-years. So, how did they help life to evolve?
In the early universe, a huge amount of insanely hot gas started coalescing to form ‘bulges’ which gave rise to galaxies. These galaxies contained a huge amount of star formation and stars would typically be massive and short-lived. If life ever got a chance to flourish, it would doom quite soon. However, when a huge amount of matter started to fall into the galaxies, the central region was capable to form the gigantic black holes we ‘see’ today. These black holes continued to grow by swallowing more and more hot gaseous matter falling into it. Besides they used to radiate away from the intense heat by blowing those outside the galaxy. However, this rapid wizardry soon came to a halt within 10 million years or so. But, by then it helped the heat to decrease and radiate evenly throughout the galaxy. This gave a chance for less massive stars like the sun to form which had billions of years of life and had the capability to harbor life. If Quasars haven’t existed, neither you read this article nor I would write it!
