Quasar

A Quasar is just one of many different types of Active Galactic Nuclei, which also include Blazars, Radio Galaxies and Seyfert Galaxy. Quasar's full name is QUASi-StAllar Radio object. The centre of the Milky Way is reputed to be just a supermassive black hole and not a quasar. It is now thought that at one time, the centre of the Milky Way was a Quasar before it became inactive like it is today. There are also Quasi-Stellar Objects (QSO) like Radio (QSR) sources, except that Objects have a large redshift in their optical spectrum. On the other hand, Radio Sources will also have a strong radio source. An object may or may not have a radio source. Both are starlike in appearance, and both are outside our galaxy. Stargazing.

Quasars are large supermassive black holes at the centre of a galaxy that is so active that it tends to outshine the stars in the galaxy. Quasars tend to have accretion discs of gas and dust; when material from the disc falls into the Quasar, it is ejected as electromagnetic radiation. Once the accretion disk is used up, it becomes passive. Quasars tend to be at the centres of galaxies far, far away.

All the Quasars we can see, albeit with the aid of a telescope, are billions of light-years away, leading scientists to believe that they are young galaxies. If we were to travel to those galaxies and see how they look today, they would probably be calm, and like any other galaxy, their streams would not be active.

One of the nearest Quasar is 3C273, it is 2.5 billion light-years away in the constellation of Virgo. Ref: N.A.S.A. . Some Quasars that have been studied were formed not long after the big bang and are many years older than 3C273. The picture below shows an N.A.S.A. artist's impression of a Quasar. A Quasar will have a stream of particles ejected from the galaxy. If it didn't, it'd be a normal galaxy

Quasar and Blazar Facts

• Quasar and Blazars are not stars, they are a type of galaxy.
• A Quasar is an Active Galactic Nuclei. It is the centre of a galaxy that is shooting out a stream of particles from the centre
• The difference between a Quasar and a Blazar is how it is angled towards us.
• The Milky Way was believed to have been a Quasar once but is currently quiet.
• The nearest Quasar to Earth is Markarian 231 in the constellation of Ursa Major.
• Quasars are so far away that they are believed to be the early stages of a galaxy.
• The first Quasar was discovered on August 5th, 1962.

You're probably wondering if a quasar is a supermassive black hole, and they only suck in everything. How can they emit streams? The short answer is that it is believed that the electromagnetic field inside a black hole is so powerful that it causes the particles to head towards the poles and then out in a stream. If this is too simplistic, have a read of what Cornell University has to say on the matter.

To look at a Quasar from Earth, they would appear as red stars. When I say look, I mean through a telescope. They are too distant and from here, too small to be seen with the naked eye. The redness is because they are so far away and because they appear in the redshift of the spectrum that they are moving away from us.

Quasars are similar to pulsars (Pulsating Stars) in that they have streams of x-rays shooting from their middles. They don't rotate as often, if ever. A Quasar is approximately 1 kiloparsec in width, 1000 parsecs, and 1 parsec = 3.26 light years. Ref: Starchild

As Quasars are so far away, their light has travelled for billions of years. Quasar ULAS J1120+0641, which has a size of over 2 billion times the mass of the Sun. It is believed to have formed only several hundred million years after the Big Bang.Ref: Space

Quasars Discovery

Marteen Schmidt, a Dutch astronomer, is credited with discovering Quasars in 1963. However, before that, the groundwork was already in place. The first Quasar to be discovered was 3C 273. The object was bright and too far away to be a star. His research helped nail a coffin in the Steady State Theory, which said that the Universe was not born in a Big Bang and has and always will be around for eternity. Carnegie

Special mention should also go to other astronomers who had helped directly and indirectly with Quasar's discovery. 3C 273 had been examined the previous year by scientists at the Parkes Radio Telescope in Australia, but it was not until the year later that the object's mystery was solved. Wired

The object is thought to have shined with the power of a trillion Sun-like stars. The object would only be less than a light-year across. For comparison, our galaxy is believed to be 100,000 light-years across. EarthSky

Quasar Luminosity / Temp.

If we use 1LMW as the luminosity of the Milky Way Galaxy, a quasar could have a luminosity power of 10 to 100,000 LMW. Luminosity is the amount of energy that a star or galaxy produces. The Luminosity of the Sun is described as 1Lsun. The Luminosity of the Milky Way is equivalent to 25 billion Lsun. You get the idea of how powerful the Luminosity of a quasar can be. Our galaxy would be outshone by even the dimmest of Quasars. The luminosity of a quasar is anything from 250,000,000,000 Sun to 2,500,000,000,000,000 times more power than the Sun. Ohio State.

What is a Blazar?

The difference between Quasar, radio galaxy and a Blazar is the angle of the stream. If the stream is straight up, it is a radio galaxy, and we are not in the firing line. If the stream is angled slightly towards us, it's a Quasar; if it is angled directly towards us, it's a Blazar.

In the beginning, when they were first discovered, they were thought to be different objects in space, but as we learned more, we discovered they were the same. There is a video on Youtube which gives a good explanation into Quasars and Blazars if you'd rather see a video.

Is The Milky Way A Quasar

Researchers trying to find the missing mass of our galaxy believe they might have found it. According to the report, the Milky Way was active some six million years ago. The Quasar phase would have been when the first human-like creatures walked on Earth. This phase would be more recent than the dinosaurs.

This timeline is corroborated by the presence of 6-million-year-old stars near the galactic centre, Sagittarius A*. Those stars formed from some of the same material that once flowed toward the black hole. Activity ended when the centre ran out of food to keep it going. Harvard

When the Andromeda Galaxy eventually collides with our galaxy, there is nothing to say. The resulting supergalaxy won't become an Active Galactic Nuclei galaxy. As the collision won't be around for a few billion years, we won't be around to see it.

Scientists have discovered six normal galaxies turning into Quasar. These galaxies are LINER (low-ionization nuclear emission-line region) galaxies such as the Sombrero Galaxy. At the time of the news, the scientists don't know why. Astronomy Now

Quasars and Hubble's Law

The Big Bang Theory, the actual theory, not the television series, is based on Hubble's Law. Edwin Hubble developed Hubble's Law in the early twentieth century. He stated that when a galaxy's light shines through a spectrograph, it is split into colours of the rainbow. If the light is more heavily red, the item moves away from the observer. If the light is bluer, the object moves closer to the observer.

When observing Quasar light, the items are redder than they should be. Using Hubble's Law, they are calculated as being at the edge of the known Universe and that they are moving at the speed of light.

Nearest Quasar to Earth?

As of August 2015, the nearest Quasar to Earth is Markarian 231 according to NASA Hubble Space Observatory. It is estimated to be about 600 million light-years away in the constellation of Ursa Major in the northern hemisphere. The galaxy is believed to have two black holes orbiting around one another.

The light we see now is how it was 600 million years ago, even before the dinosaurs roamed the Earth over 250 million years ago. The central black hole is believed to be 150 million times the mass of the Sun and weighs over 4 million times the mass of the Sun.

Even though the Quasar is so far away and old, it is believed that the two black holes orbit around each other for 1.2 years. The reason why they are believed to be in orbit around one another is the result of two galaxies colliding. The two black holes will have already collided by now, but we will not see the effect of the collision here on Earth for another few hundred thousand years. ref:N.A.S.A.

Quasar vs Pulsar vs Magnetar

Even though a Quasar and a Pulsar have the same ending, which might make people think that they are the same type of object, they aren't. In the simplest explanation, a Quasar is a supermassive black hole in a galaxy, and a Pulsar is the rotating remnants of a dead star. A Quasar can be light-years in diameter, whereas a Pulsar might only be as small as Manhattan Island in New York. A Magnetar is roughly about or larger than a Pulsar.

A Quasar is at the centre of a galaxy. They are billions of light-years away and very young. If you were to travel to a Quasar now, they probably wouldn't be active and be a normal galaxy. Quasars won't be active forever; they will only be long enough to excrete all the necessary material.

A Pulsar is a rotating neutron star. They exist within a galaxy such as ours. A Pulsar is created in the aftermath of a star having gone supernova, and it is remnants. A pulsar, known as a millisecond pulsar, can rotate many times a second.

A Magnetar is a powerful pulsar with a magnetic field many times stronger than a Pulsar. In terms of size, the Quasar/Blazar are the larger of the comparison group.

Is a Quasar a White Hole?

No, they are two different things. A white hole is a black hole's unproven theoretical exit point that no one has yet discovered. It seems strange that all the black holes are pointing towards us. If white holes existed, surely there would be some pointing towards us.

The equivalent of a white hole in a quasar would be the stream. The stream from a quasar is the ejected matter that the galaxy's centre has accumulated and is ejecting because it no longer needs or requires it.

Quasar in the Night Sky?

Even though a Quasar is an extremely bright and powerful object, it is impossible to see one just by looking up at the sky. The furthest thing we can see with our naked eye is the Andromeda Galaxy, which is a mere 2.4 million light-years away. Quasars are billions of light-years away. You would need a telescope of at least 8 inches to see the brightest Quasar in the sky.

List of Quasar Examples

• 3C 48
• 3C 279
• NGC 3862
• NGC 6061
• Markarian 205
• NGC 6166
• 3c 186, Rogue Supermassive Black Hole
• EINSTEIN CROSS
• 3C 9