(ORDO NEWS) — Quasars are one of the brightest objects in the visible universe and it is possible that they are the most powerful energy sources.
Since their discovery in the 1960s, more than 7,000 quasars have been discovered, but scientists are confident that there are tens of millions of similar objects in the visible part of the Universe, and the available technologies will help to detect them.
The term “quasar” (quasar) is formed from the two words quasi-stellar (similar to a star) and radiosource (radio source), which literally means “radio source, similar to a star.”
However, as is now known, there are also quasars that do not show much activity in the radio range.
The existing cosmological model describes a quasar as an active galactic nucleus in which there is a supermassive black hole with a rapidly increasing mass.
Due to the growing activity of the black hole, matter begins to stretch into the surrounding space, emitting powerful radiation.
As observations show, the radiation power of a quasar can be hundreds of times higher than the total power of all the stars in the Milky Way.
Bias
Redshift is one of the most amazing properties of quasars. According to the Doppler effect , the shift of spectral lines towards red indicates that the object is moving away from the observer at great speed.
This feature was first discovered by the Dutch astronomer Marten Schmidt in 1963, and this allowed him to measure the distance from the Earth to quasars.
Distance
If the rate of removal of quasars from the Earth is associated with the expansion of the Universe (few doubt this), then based on the law of Edwin Hubble , quasars should currently be at a great distance from us.
This is confirmed, since the distance to the most distant quasars is more than 10 billion light years, and the distance from observers from the Earth is carried out at near-light speed.
Some of the most distant known galaxies are much closer than quasars and move away from the Earth at a slower speed, which is several times less than the speed of quasars.
This phenomenon made it possible to prove that distant objects move away faster than nearby ones.
Observation
It is impossible to see a quasar in the night sky, and an observatory is required for observation.
But how is it, if quasars are among the brightest objects? Observing quasars with the naked eye will not work because of too great a distance.
Size and lifespan
Due to the incredible speed of movement, the brightness of the observed quasar can change over several days. However, the available data collected over decades of observations allow us to draw some conclusions.
It is known that quasars are relatively compact objects and their size can be comparable to the size of the solar system.
The lifetime of quasars is several million years, since it takes a huge amount of energy to maintain such a brightness.
When the reserves of “fuel” come to an end, then… it’s hard to say what will happen next, since we have never observed the death of quasars.
Quasar model
A quasar’s main source of energy is the gravitational field of a supermassive black hole, which destroys anything that gets too close.
When a black hole tears apart large stars, a large amount of gas is released, forming an accretion disk, which begins to shrink towards the center of the hole.
Extreme compression and rapid rotation lead to the fact that the gas begins to heat up to enormous temperatures. The matter of the accretion disk is partially absorbed by the black hole, which begins to grow.
Another part of the substance of the accretion disk is “catapulted” in the form of streams of hot gas and radiation.
As before, quasars remain little-studied objects, about the origin of which there are many hypotheses. Why do quasars appear?
What will happen to the quasar at the end of its life cycle? Will a quasar appear in the Milky Way? There are no exact answers to these questions.
That is why it is necessary to continue the study of quasars and collect all kinds of data in order to draw objective conclusions and learn to predict the future, at least within our own galaxy.
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