Physics
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Quasars

Quasars

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Quasars are fascinating objects in space that were first discovered because of their high radio-wave emissions. They looked like faint, star-like points, but scientists soon realized that they were not stars at all. In fact, these objects had a very large redshift compared to stars which indicated that they were something else entirely. The name "quasar" comes from the expression "quasi-stellar," which means-like. Despite being emitting very large radiation at star-like levels, standard characteristics indicating a star were missing. Scientists later discovered that quasars were supermassive black holes that released a tremendous amount of energy when matter fell into them.

When the light from objects in the universe is observed, it can indicate several features. Redshift is when the spectrum is shifted towards the red end of the spectrum where the wavelengths are larger. In the case of quasars, this further indicates that the object is moving away from the observer on Earth. In fact, the more distant the object, the faster it moves. Quasars were found with a dramatic redshift, implying they were moving very fast. This means that they must be at the very edge of the expanding universe moving away from us, thus explaining the shift in the wavelength.

In simple terms, redshift is the stretched appearance of light when an object is moving away from an observer. The opposite effect occurs when objects are moving towards the observer. The wavelength of the light wave decreases while the corresponding frequency appears to be increased. Hence the wave appears to be closer to the blue end of the electromagnetic spectrum, and the light is said to be blueshifted.

In conclusion, quasars are supermassive black holes that emit a tremendous amount of energy when matter falls into them. They were first discovered because of their high radio-wave emissions and appeared like faint, star-like points. The redshift of quasars indicates that they are moving away from us, and the more distant the object, the faster it moves.

The creation of a Quasar

A quasar is an astronomical object that is created by the interaction of matter around a supermassive black hole. These black holes are formed when the mass of a star is contracted into a very small space, creating a gravitational pull so strong that even light cannot escape. This minimum radius is called the Schwarzschild radius.

Inside the Schwarzschild radius, particles are trapped by the supermassive black hole's gravitational pull. Outside this radius is the black hole diameter, also known as the event horizon. The debris, gases, and particles around the black hole are attracted by the very large gravitational forces, causing them to accelerate with speeds close to the speed of light and collide with each other. This collision releases huge amounts of energy.

The energy emitted from the accretion disk is known as a quasar. It is in the form of electromagnetic radiation that travels at the speed of light. Since the emitted energy is around the event horizon, it can actually escape and be detected.

The event horizon of a black hole
The event horizon of a black hole

How are quasars discovered?

Quasars release a lot of bright light, and sometimes emit a stream of jet in the form of radio waves. However, the jet's emission is only active when there is matter in the accretion disk. Once the matter is consumed, the quasar becomes inactive and is very difficult to detect. There are hundreds of thousands of known quasars, and the oldest known neon quasar is 780 million years old, providing clues about the earliest stages of the universe.

Quasars can only form when supermassive black holes are present. The larger the size of the black hole, the greater the gravitational field will be around the black hole. Therefore, the collisions of matter will be greater and more violent, resulting in quasars. The sizes of the black hole and quasars are an indication of their age, as supermassive black holes can only exist in the distant areas of the universe, as they must have existed and consumed matter for a long time.

In conclusion, quasars are large amounts of energy being released from the collision of debris around a black hole. They were named as such because they emit a huge amount of energy like stars. Redshift is a phenomenon where light is shifting towards the red end of the electromagnetic spectrum, indicating that the object is moving away from the observer. Quasars are discovered by radio telescopes detecting the radio waves emitted from the quasars' jets.

Quasars

What is a quasar?

A quasar is energy in the form of electromagnetic radiation being released from the collision of matter (particles, gases, stars) orbiting supermassive black holes near the event horizon.

How were quasars discovered?

Quasars were first detected using radio telescopes that detected tremendous energy being released, which resembled star-like energy emission.

What is the brightest quasar?

The brightest quasar known is called 3C 273 and is in the constellation of Virgo.

Is a quasar a black hole?

A quasar is not a black hole, but the energy that is released from the collision of matter around a black hole.

What causes a quasar?

A quasar is caused from the matter that surrounds a black hole in an accretion disk experiencing gravitational forces and heating up, resulting in collisions, which releases energy in the form of electromagnetic radiation.

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