Page 35 - Curriculum Visions Dynamic Book

Quasars
qUasar stands for quasistellar radio sources. It represents a powerful source of radio waves, X-rays, and light.
Quasars are no more than a light-year or two in size, but they are up to 1,000 times brighter than giant galaxies. They are true pinpoints of light in the sky.
Quasars were first discovered in 1963. Since then, more than 15,000 quasars have been found, and we now know that they are the luminous cores at the heart of many galaxies. Quasars send out radiation a million million times as powerful as the radiation from the Sun from a space no bigger than the Solar System.
Black holes
Neutron stars, pulsars, and quasars are all associated with very small sources of intense energy set within the remains of a star in a galaxy.
But they may all have something in common. They may be connected to another feature of some galaxies that we cannot see, and that does not directly send out radio or X-ray waves. We only know this feature is there because of its effect on its surroundings.
electrons Negatively charged particles that are parts of atoms.
magnetic field The region of influence of a magnetic body.
neUtrons Particles inside the core of an atom that are neutral (have no charge).
neUtron star A very dense star that consists only of tightly packed neutrons. It is the result of the collapse of a massive star.
protons Positively charged particles from the core of an atom.
pUlsar A neutron star that is spinning around, releasing electromagnetic radiation, including radio waves.
qUasar A rare starlike object of enormous brightness that gives out radio waves, which are thought to be released as material is sucked toward a black hole.
radiation The transfer of energy in the form of waves (such as light and heat) or particles (such as from radioactive decay of a material).
radio Waves A form of electromagnetic radiation, like light and heat. Radio waves have a longer wavelength than light waves.
rotation Spinning around an axis.
x-ray An invisible form of radiation that has extremely short wavelengths just beyond the ultraviolet.
 This is a quasar in the southern constellation Hydra, located about 10 billion light-years away. In this image we can only see things that are bigger than 10,000 light-years across.
The quasar is the pointlike object at the center
of the images. It has two arclike and knotty tails extending in different directions. The tails are probably due to the closeness of the galaxy the quasar is in and to a nearby galaxy. The longer, southern tail extends over more than 150,000 light-years, one and a half times the diametre of the Milky Way.
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