What is a Quasar?

Quasars, astronomical terms, are abbreviations similar to stellar celestial bodies, also known as quasars, queens, or quasar-like power sources, and together with pulsars, microwave background radiation, and interstellar organic molecules, they are called the "Big Four" of astronomy in the 1960s. Find". It has long puzzled astronomers.

In 1960, American astronomers

Quasars are a special type of celestial body discovered in 1963. They are named after what appear to be "star-like objects", but they are actually distant celestial bodies with huge energy outside the Milky Way, and their centers are supermassive masses that are violently engulfing the surrounding material and above the mass of 10 million solar masses.

Under sync

In the mid-1990s, with the improvement of observation techniques, the mysteries of quasars began to be gradually revealed. One important result is the observation of quasar "host galaxies" and their redshift values. Because the quasar's light is too bright, which masks the relatively dim light of the host galaxy, the host galaxy has not attracted people's attention before. Until similar observations were installed on the telescope

In the mid-1990s, with the improvement of observation techniques, the mysteries of quasars began to be gradually revealed. One important result is the observation of quasar "host galaxies" and their redshift values. Because the quasar's light is too bright, which masks the relatively dim light of the host galaxy, the host galaxy has not attracted people's attention before. It wasn't until the telescope was installed with an instrument like a coronagraph for observing the solar atmosphere, blocking the bright light of quasars, and then observing their host galaxies.

Now the scientific community has reached a consensus that quasars are actually a type of active galaxy nucleus (AGN). In the same period, the Seifert Galaxy and the Lagoon BL celestial body have also been confirmed as active galaxy nuclei. An active galaxy nucleus model that attempts to unify radio galaxies, quasars, the Seifert galaxy and the Lagoon BL celestial body has gradually become widespread. Approved.

This model believes that there is a super-massive black hole in the core of the galaxy. Under the strong gravitational force of the black hole, nearby dust, gas, and a part of the stellar matter surround the black hole, forming a huge accretion disk rotating at high speed. At the inside of the accretion disk, near the horizon of the black hole, the material fell into the black hole, and with the huge energy radiation, a jet of matter was formed. The strong magnetic field constrains the jets of these substances so that they can only spray at high speeds along the direction of the magnetic axis, usually perpendicular to the plane of the accretion disk. If these jets are just facing the observer, quasars are observed. If the observers observe the active galaxy nucleus from different perspectives, the active galaxy nucleus will appear as radio galaxies, Seifert galaxies, and Lagoon BL celestial bodies, respectively. In this way, the energy problems of quasars have been initially resolved.

Quasars are different from ordinary "quiet" galaxy nuclei in that quasars are young, active galaxy nuclei. From the fact that quasars have large redshift values and are far away, it can be inferred that the quasars we see are actually what they were many years ago, and the quasars are likely to have been commonly experienced in the early stages of galaxy evolution. One stage. As the "fuel" near the core of the galaxy runs out, quasars will evolve into ordinary spiral galaxies and elliptical galaxies. ^[6]

China discovers super black holes and brightest quasars in the early universe with small telescopes ^{[5] [7]}

Peking University has announced that a team led by Wu Xuebing, a professor of astronomy at the school s physics department, has discovered a superbright quasar that is 12.8 billion light years away from humans. Its luminous intensity is 430 trillion times that of the sun and its central black hole has a mass of about 12 billion solar masses. It is currently the brightest and most quasar with a central black hole in the universe. This early super monster of the universe was first discovered by Chinese scholars using the 2.4-meter telescope in Lijiang, Yunnan, and it is also the only early quasar in the universe with a redshift of 6 or more found by a 2-meter telescope in the world. The red-shifted 6.3 quasar SDSS J0100 + 2802 was found to have the highest luminosity and black hole mass among all high-redshift quasars.

Illustration of quasars with huge black holes in the distant universe ^[5]

The latest research results were published in the latest international scientific journal Nature on February 26, 2015.

Chen Jiansheng, a well-known astronomer and an academician of the Chinese Academy of Sciences, commented on the discovery: "Chinese astronomers can use domestic 2-meter telescopes to discover celestial bodies that usually require 10-meter telescopes in the world, indicating that Chinese astronomers have innovative ideas." ^[8]

"Nature" also specially published a press release entitled "Young black hole had monstrous growth spurt" for this article, and invited the Max Planck Institute for Astronomy in Germany

Discovered redshift 6.3 quasar SDSS J0100 + 2802 ^[5]

Dr. Bram Venemans wrote a special article entitled "A giant in the young Universe" in the "News and Commentary" section of the same period magazine. Find.

In just a few days, foreign news media, including CNN, Reuters, Washington Post, Time, National Broadcasting Corporation (NBC), National Geographic, Discovery Channel, Scientific American, etc., and domestic news Media, such as China Central Television, Xinhua News Agency, People's Daily, Guangming Daily, China Daily, and China Science Daily, have reported this discovery as important news. Peking University also held a special press conference for this purpose, with more than 20 reporters from major domestic media participating.