What exactly is a quasar? Is there a quasar behind each black hole, and are these two things essentially the same?
If you’ve ever asked yourself the above questions, you’re not alone.
You don’t need us to tell you that space is a large, mystical place with more questions than answers, and quasars and black holes are two of the universe’s most confused and discussed concepts.
If you want to learn more about quasars and black holes, keep reading to discover what they are, how they work, and just how similar they actually are.
- What Is A Quasar?
- When Were Quasars First Discovered?
- How Do Quasars Work?
- How Do We Know That This Happens?
- What Is A Black Hole?
- Are All Quasars Black Holes?
- Are Quasars And Black Holes The Same Thing?
- Quasars And Black Holes: The Similarities And Differences
- Are Quasars A Threat To Earth?
- What Can We Learn From Quasars?
- Final Thoughts
What Is A Quasar?
Quasars are very distant galaxies that emit powerful radio waves.
They are usually found at the edge of our galaxy, appearing as bright spots in space.
The light from these objects has taken billions of years to reach us.
Black holes are also extremely massive, and they are believed to be at the center of quasars.
Scientists believe that quasars are powered by supermassive black holes located at their centers.
These black holes are millions or even billions of times more massive than the Sun.
Scientists believe that these black holes are formed after a star collapses under its gravity, leading to a huge supernova explosion.
The debris from the supernova then forms a disk around the black hole. The debris falls into the black hole as time passes, creating a quasar.
When Were Quasars First Discovered?
The first quasar was discovered in 1963 by astronomer Maarten Schmidt, who noticed an unusual pattern of stars near the center of our Milky Way Galaxy.
This pattern indicated that something else must have been moving through the area.
After studying this strange phenomenon for several months, he realized it was caused by a new type of astronomical object: a quasar.
How Do Quasars Work?
Quasars were originally thought to be some kind of giant star. However, they are made up entirely of gas.
Gas is a form of matter that can move freely throughout space. It does not require energy to exist, so it naturally exists everywhere in space.
Gas clouds are often associated with young stars. When a star dies, the gases inside the star collapse and create a massive cloud.
If the star is huge enough, the gases will eventually fall into the star’s core. Ultimately, the star becomes a neutron star or a black hole.
In other cases, the star may explode violently, causing the gases to expand outward.
As the gas expands, it begins to cool down. Once the temperature drops below a certain point, the gases glow brightly.
This glowing gas is known as ionized hydrogen gas (HI). When astronomers look at HI gas, they see it glows because it contains many electrons.
Electrons are negatively charged particles. Because of this negative charge, the gas creates a strong electric field.
This electric field causes the gas to radiate energy. This energy is visible as light.
So when we observe a quasar, we see the light emitted by the gas surrounding the black hole.
How Do We Know That This Happens?
Scientists use telescopes to study quasars.
In fact, one of the first quasars was discovered when scientists used an optical telescope to look for stars near the center of the Milky Way.
When they looked through the telescope, they saw a faint blue glow. It turned out that this glow came from an incredibly distant galaxy.
Since then, astronomers have been able to find many other quasars using optical telescopes.
Astronomers can also detect quasars using radio telescopes.
Radio waves travel much further than visible light, so it’s easier to see them coming from far away galaxies.
But because radio waves are blocked by Earth’s atmosphere, only radio telescopes on high-altitude balloons or satellites can see them.
What Is A Black Hole?
Black holes are regions of space with no escape velocity. If something gets too close to a black hole, it will fall into it.
There’s no way to get out once you enter a black hole.
The mass of a black hole is measured in units called solar masses (M☉). One M☉ is equal to 1 million Suns.
So if you had a black hole as big as the Sun, it would weigh over 4 billion tons!
The size of a black hole depends on how fast it spins. If a black hole rotates quickly, it creates a strong magnetic field.
This magnetic field traps charged particles inside the black hole, including electrons and protons. This makes it difficult for anything to escape.
But if a black hole doesn’t spin very fast, it may not create enough magnetic fields to trap any particles.
Instead, it becomes a “dormant” black hole. Dormant black holes are smaller than normal ones but still contain lots of matter.
So why do we call black holes dark? Because nothing can escape from a dormant black hole. And since nothing can escape, it looks like a black hole.
Are All Quasars Black Holes?
No, not all quasars are black holes. Some are simply normal galaxies that happen to lie close enough to Earth to see them.
Other quasars are made up of multiple smaller galaxies that orbit together, and some quasars are giant clouds of gas and dust.
So why do people call all quasars “black holes”? Well, if a quasar is really a single galaxy, it would be impossible to see any individual stars within it.
Because of this, scientists refer to the entire thing as a “quasar.”
If a quasar is really made up of several smaller galaxies, it might be possible to see individual stars.
However, because the stars are so far away, they appear tiny compared to the size of the quasar itself.
Are Quasars And Black Holes The Same Thing?
Essentially yes, they are! Both quasars and blackholes are very massive objects that sit at the center of galaxies.
But while black holes are invisible, quasars shine brightly across the electromagnetic spectrum.
So they both serve as markers for the location of a supermassive black hole.
Quasars And Black Holes: The Similarities And Differences
Both quasars and black holes are extremely large. A typical quasar is about 100 billion (1011) times larger than the Sun.
A regular black hole is about 10 million (109) times bigger than the Sun.
But what makes them similar? They both form in the middle of a galaxy.
They’re both very hot — with temperatures ranging from thousands of degrees Celsius to tens of thousands of degrees Celsius, and they’re both surrounded by a cloud of glowing gases.
But there are differences between quasars and black holes too. For example, quasars don’t spin like black holes.
Instead, they rotate around their axis at speeds of over half a million kilometers per hour.
Also, quasars are usually found in elliptical galaxies, but black holes are usually found in spiral galaxies.
Are Quasars A Threat To Earth?
Not likely. Although quasars are incredibly bright, they’re not powerful enough to affect our planet.
Most of the energy emitted by a quasar comes from its active galactic nucleus, hundreds of millions of light-years away.
Even if the quasar were directly aimed at us, it wouldn’t be strong enough to cause damage.
What Can We Learn From Quasars?
Quasars help us learn more about how galaxies work.
By studying the properties of quasars, astronomers have learned a lot about the structure of our own Milky Way Galaxy.
In addition, quasars provide clues about the history of our universe.
The similarities between quasars and supermassive black holes are striking. It’s easy to think of them as two sides of the same coin.
But even though they look alike, quasars and blackhole aren’t exactly the same things. So they’re actually quite different.
Black holes are much more mysterious than quasars. While we know a lot about quasars, we still don’t understand the nature of black holes.
But the study of quasars has helped us learn a lot about the physics of galaxies.
And in turn, this knowledge has led to new discoveries about our own solar system.
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