Seeing minus infinity…almost!

On 23^rd April 2009, NASA’s SWIFT satellite recorded the farthest star burst ever in the history of astronomy. The observation with acronym GRB 090423 (GRB is gamma ray burst) recorded a red shift of 8.2, which corresponds to an event in the universe as early as 630 million years since big bang. The accompanying picture is from Gemini North Telescope in Hawaii, USA. On the electromagnetic spectrum, gamma rays are at the blue end, which makes them most energetic radiation. The gamma ray bursts essentially occur due to collapse of a massive star at a distant galaxy to form a black hole. Tremendous amount of energy is released during this event which acts a window to decipher many of the puzzles of early universe. These bursts are also dubbed as novas and supernovas depending on their intensity. One of the spectacular aspects of these bursts is the relativistic jets along the axis of the rotation of the collapsing star. These jets are collimated emission of radiation, which arise due to the frictional collapse of matter towards the center of the black hole. It has been estimated that energy as much as 10⁴⁴ J is released during this process. However, the mechanism of the collimated emission is still under debate in astrophysics. The initial burst of gamma rays is followed by an afterglow of other electromagnetic radiation like x-rays, UV, visible etc. which unveil a wealth of information about the collapsing stars in other galaxies. It is indeed a wonder that what we see in these burst is not only an event which is very, very far from us, but also something which happend when the universe was a mere one-twentieth of its current age. Well, for me, this is almost as good as seeing minus infinity !