Maarten Schmidt solves the mystery of quasars | Space

Today in science: On 5 February 1963, the Dutch astronomer and professor at Caltech Maarten Schmidt had a eureka moment when he quasi-star radio source, or kwasar, which had far-reaching consequences for how scientists would view the universe. Schmidt studied a quasar known as 3C273 which had a star-like appearance with the addition of a mysterious radiator. But even stranger was its spectrum. Astronomers study the spectrum, or magnitude, of the wavelengths of light emitted by a star to decipher the composition of the object. But the emission lines of the spectrum of 3C273 does not correspond to any known chemical elements. Schmidt suddenly realized that 3C273 contains the very common element hydrogen. It was just difficult to identify because the spectral lines of hydrogen did not appear as expected; instead, it is strongly shifted to the red end of the spectrum. Such a large redshift could occur if 3C273 were very far away, about 3 billion light-years away.

Dr. Schmidt remembers the excitement of his revelation to EarthSky. He said:

This realization came immediately: my wife still remembers moving up and down most of the evening.

The implications were just that: for the quasar to be so far away and still be visible, 3C273 must be intrinsically very bright and very powerful. It is now thought to shine with the trillion stars as our sun. This is hundreds of times the light of our entire Milky Way system. Yet 3C273 appears to be less than a light-year, as opposed to 100,000 light-years for our Milky Way.

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The quasar 3C273 is not only far away. It is also extremely clear and implies powerful energy-producing processes that were unknown in 1963. Schmidt announced his revelation about quasars in the magazine. Nature on March 16, 1963.

Today, hundreds of thousands of quasars are known, and many are farther and more powerful than 3C273. It is no exaggeration to say that they have turned the science of astronomy on its ears. Why are these powerful quasars located so far in space, for example? Light moves at a finite speed (186,000 miles per second) and we only see quasars in the distant space and therefore in the distant past. These strange objects only existed in the early universe and no longer exist in the present universe. Why?

In the 1960s, 3C273 and other quasars as such were strong evidence against Fred Hoyle’s Steady State theory, which suggested that matter is constantly being created as the universe expands, resulting in a universe that is the same everywhere. The quasars have shown that the universe is not the same everywhere and thus helps to introduce the big bang cosmology.

But the Steady State theory had already lost ground before 1963. The biggest change caused by Maarten Schmidt’s revelation about the quasar 3C273 was in the way we Think about our universe.

In other words, the idea that 3C273 was extremely bright and yet occupies such a relatively small space indicates powerful energies that astronomers have not previously considered. 3C273 gave astronomers one of their first hints that we are living in a universe of colossal explosive events – and extreme temperatures and brightness – a place where mysterious black holes abound and play an important role.

According to a March 2013 email from Caltech:

In 1963, Schmidt’s discovery gave us an unprecedented look at how the universe behaved at a much younger time in its history, billions of years before the birth of the sun and its planets. Later, Schmidt, along with his colleague Donald Lynden-Bell, discovered that quasars are galaxies that contain supermassive black holes billions of light-years from home, not stars in our own galaxy, as once believed. His core work has dramatically increased the scale of the observable universe and promoted our current view of the violent nature of the universe in which large black holes play a dominant role.

What are quasars? Astronomers today believe that a quasar is a compact region at the center of a galaxy in the early universe. It is suspected that the compact region surrounds a central supermassive black hole, just as the black hole is at the center of our own Milky Way galaxy and many (or most) other galaxies. It is suspected that the powerful brightness of a quasar is the result of processes occurring in a growth disk, or disk material that surrounds the black hole, as these supermassive black holes consume stars that pass too close. This type of activity occurs during mergers of galaxies, which reached a peak in the early universe.

Chinese-born American astrophysicist Hong-Yee Chiu coined the name kwasar in May 1964 in the publication Physics today. He wrote:

So far, the clumsy long name ‘quasi-star radio sources’ is used to describe these objects. Because the nature of these objects is completely unknown, it is difficult to prepare a short, appropriate name for them so that their essential properties are clear from their name. For convenience, the abbreviated form ‘kwasar’ will be used throughout this question paper.

Currently, the most famous quasar is ULAS J1342 + 0928, but it can be dethroned at any time. It has a redshift of z = 7.54 and existed when the universe was about 690 million years old, only 5% of its current age.

In short: Today in science, on February 5, 1963, Maarten Schmidt unraveled the mystery of quasars and pushed back the edges of our cosmos. His insight into the farthest and brightest objects known has changed the way scientists view the universe.

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