PULSAR are have exceed heat energy in them. They are so brigt. When they strikes any star or planet, the whole or 2-3 nearby galaxies can destroyed. Pulsar are in the shape of plus (+) and in the meet point, a bright circle is pulsar.
Let the Hitech intro about Pulsars-
A pulsar is a neutron star which emits beams of radiation that sweep through the earth's line of sight. Like a black hole, it is an endpoint to stellar evolution. The "pulses" of high-energy radiation we see from a pulsar are due to a misalignment of the neutron star's rotation axis and its magnetic axis. Pulsars pulse because the rotation of the neutron star causes the radiation generated within the magnetic field to sweep in and out of our line of sight with a regular period.
THE GAMMA RAY OF THE PULSARS
OBSERVATION OF THE PULSAR
Neutron stars have very intense magnetic fields, about 1,000,000,000,000 times stronger than Earth's own field. However, the axis of the magnetic field is not aligned with the neutron star's rotation axis. The combination of this strong magnetic field and the rapid rotation of the neutron star produces extremely powerful electric fields, with electric potential in excess of 1,000,000,000,000 volts. Electrons are accelerated to high velocities by these strong electric fields. These high-energy electrons produce radiation (light) in two general ways: (1) Acting as a coherent plasma, the electrons work together to produce radio emission by a process whose details remain poorly understood; and (2) Acting individually, the electrons interact with photons or the magnetic field to produce high-energy emission such as optical, X-ray and gamma-ray. The exact locations where the radiation is produced are uncertain and may be different for different types of radiation, but they must occur somewhere above the magnetic poles. External viewers see pulses of radiation whenever this region above the the magnetic pole is visible. Because of the rotation of the pulsar, the pulses thus appear much as a distant observer sees a lighthouse appear to blink as its beam rotates. The pulses come at the same rate as the rotation of the neutron star, and, thus, appear periodic.
Gamma-ray PulsarsPulsars are the original gamma-ray astronomy point sources. A few years after the discovery of pulsars by radio astronomers, the Crab and Vela pulsars were detected at gamma-ray energies. Pulsars accelerate particles to tremendous energies in their magnetospheres. These particles are ultimately responsible for the gamma-ray emission seen from pulsars.
By the end of 2004 there were about 1500 pulsars known through radio detections, but only seven had been detected in the gamma-rays. Gamma-ray telescopes preferentially detect young, nearby pulsars. These pulsars tend to have large magnetic fields and to be spinning rapidly. It is the loss of the pulsar's spin energy which eventually appears as radiation across the electromagnetic spectrum, including gamma-rays. Both observations and models indicate that pulsars eventually lose the ability to emit gamma-rays as the pulsar slowly takes longer and longer to rotate.
Gamma-ray PulsarsPulsars are the original gamma-ray astronomy point sources. A few years after the discovery of pulsars by radio astronomers, the Crab and Vela pulsars were detected at gamma-ray energies. Pulsars accelerate particles to tremendous energies in their magnetospheres. These particles are ultimately responsible for the gamma-ray emission seen from pulsars.
By the end of 2004 there were about 1500 pulsars known through radio detections, but only seven had been detected in the gamma-rays. Gamma-ray telescopes preferentially detect young, nearby pulsars. These pulsars tend to have large magnetic fields and to be spinning rapidly. It is the loss of the pulsar's spin energy which eventually appears as radiation across the electromagnetic spectrum, including gamma-rays. Both observations and models indicate that pulsars eventually lose the ability to emit gamma-rays as the pulsar slowly takes longer and longer to rotate.
X-RAY PULSAR
Although all pulsars are neutron stars, not all pulsars shine in the same way. X-ray pulsars in particular illustrate several ways in which pulsar emission can originate:
Magnetospheric Emission: Like gamma-ray pulsars, X-ray pulsars can be produced when high-energy electrons interact in the magnetic field regions above the neutron star magnetic poles. Pulsars seen this way, whether in the radio, optical, X-ray, or gamma-ray, are often referred to as "spin-powered pulsars," because the ultimate source of energy comes from the neutron star rotation. The loss of rotational energy results in a slowing of the pulsar spin period.
Cooling Neutron Stars: When a neutron star is first formed in a supernova, its surface is extremely hot (more than 1,000,000,000 degrees). Over time, the surface cools. While the surface is still hot enough, it can be seen with X-ray telescopes. If some parts of the neutron star are hotter than others (such as the magnetic poles), then pulses of thermal X-rays from the neutron star surface can be seen as the hot spots pass through our line of sight. Some pulsars, including Geminga (see above), show both thermal and magnetospheric pulses.
Accretion: If a neutron star is in a binary system with a normal star, the powerful gravitational field of the neutron star can pull material from the surface of the normal star. As this material spirals around the neutron star, it is funneled by the magnetic field toward the neutron star magnetic poles. In the process, the material is heated until it becomes hot enough to radiate X-rays. As the neutron star spins, these hot regions pass through the line of sight from the Earth and X-ray telescopes see these as X-ray pulsars. Because the gravitational pull on the material is the basic source of energy for this emission, these are often called "accretion powered pulsars."
Magnetospheric Emission: Like gamma-ray pulsars, X-ray pulsars can be produced when high-energy electrons interact in the magnetic field regions above the neutron star magnetic poles. Pulsars seen this way, whether in the radio, optical, X-ray, or gamma-ray, are often referred to as "spin-powered pulsars," because the ultimate source of energy comes from the neutron star rotation. The loss of rotational energy results in a slowing of the pulsar spin period.
Cooling Neutron Stars: When a neutron star is first formed in a supernova, its surface is extremely hot (more than 1,000,000,000 degrees). Over time, the surface cools. While the surface is still hot enough, it can be seen with X-ray telescopes. If some parts of the neutron star are hotter than others (such as the magnetic poles), then pulses of thermal X-rays from the neutron star surface can be seen as the hot spots pass through our line of sight. Some pulsars, including Geminga (see above), show both thermal and magnetospheric pulses.
Accretion: If a neutron star is in a binary system with a normal star, the powerful gravitational field of the neutron star can pull material from the surface of the normal star. As this material spirals around the neutron star, it is funneled by the magnetic field toward the neutron star magnetic poles. In the process, the material is heated until it becomes hot enough to radiate X-rays. As the neutron star spins, these hot regions pass through the line of sight from the Earth and X-ray telescopes see these as X-ray pulsars. Because the gravitational pull on the material is the basic source of energy for this emission, these are often called "accretion powered pulsars."
FOR EXTRA INFO. VISIT- http://imagine.gsfc.nasa.gov/docs/science/know_l2/pulsars.html
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