Context
Astronomers using the European Southern Observatory's (ESO) Very Large Telescope (VLT) recently discovered the quasar, called P172+18, which is so far away that it takes about 13 billion years for the light from this quasar to reach Earth
What are the key-findings?
- The newly discovered quasar is called P172+18.
- It was found in a sky survey using optical light, and had colors that indicated it was at great distance.
- A follow-up observation confirmed its great distance: About 13 billion light years (or, more accurately, it took 13 billion years for the light to reach us).
- The distant, jet-shooting quasar is powered by a supermassive black hole that's about 300 million times more massive than Sun and is growing quickly, pulling in and swallowing surrounding matter with its gravity.
- While the new find is not the most distant quasarever detected, it appears to be the most distant radio-loud quasar, or radio jet-emitting quasar.
Quasar
- The word quasar is short for "quasi-stellar radio source".
- Quasar is a type of active galactic nucleus.
- In addition to radio waves and visible light, quasars also emit ultraviolet rays, infrared waves, X-rays, and gamma-rays and are brightest objects in the universe
- They are thought to be powered by super massive black holes which lie at the center of massive galaxies.
- However, the black holes themselves do not emit visible or radio light (i.e. they are “black”) – the light we see from quasars comes from a disk of gas and stars called an accretion disk, which surrounds the black hole.
- Quasar emission can only last as long as there is fuel available to form an accretion disk.
- Quasars can consume up to 1000-2000 solar masses of material per year, and have typical lifetimes of around 100-1000 million years. Once they have exhausted their fuel supply, the quasar will “turn off”, leaving the much fainter host galaxy.
|
