Thursday 21 March 2013

What are Quasars?

The name Quasar, is a short for Quasi-stellar radio source. Quasars are very bright centers of young galaxies that are very far away. The light they make takes billions of years to reach us, so looking at a quasar is like viewing the birth of a galaxy long, long ago. These ultra-bright objects are likely the centers of active galaxies where super massive black holes are. As material spirals into the black holes, a large part of the mass is converted to energy. It is this energy that we see and thought smaller than our system a single quasar can outshine an entire galaxy of a hundred billion stars.

Wednesday 20 March 2013

How do Quasars form?

A Quasar is formed by a super, massive black hole sucking in a considerable amount of matter in an acceleration disk. A black hole is a region of space having a gravitational field so intense that no matter or radiation can escape. This causes the matter to begin spinning around this disk. And, because it is an acceleration disk, the matter will continue to speed up on a regular basis. As the matter speeds up more and more, it will begin to heat up. As it heats up, the matter begins to rub against other bits of matter. This causes friction which, in return, results in light. this light is what is visible to us. Quasar jets are streams of plasma that travel at near the speed of light from super massive black holes at the center of galaxies.

Tuesday 19 March 2013

What do Quasars look like?

Quasars are so far away that you cant get a real picture of them. Most of the pictures on quasars have been made by artists drawn or sketched on the computer. They look like stars when you see them, that are so far away that most of them look like single bright lights in the sky.

Sunday 17 March 2013

How were Quasars discovered?

The discovery of Quasars were really spread over time. In the 1950s several radio sources were matched with very dim optical objects that looked like stars but had a strange spectra with a lot of ultraviolet excess. Ultraviolet means the electromagnetic radiations at wave lengths are shorter than the violet end of visible light. one of them, 3C 273 had it's position very accurately measured by C. Hazard and co-workers. In 1962, M. Schmidt obtained a spectrum of this "star", which showed a redshift. This is when Quasar-stellar objects were discovered because this was a very distant object that was showing as a star, a quasi-stellar object.