A team of scientists has obtained the closest image of a quasar in history thanks to NASA’s Hubble telescope and a sophisticated observation method. Quasars are considered the brightest phenomena in the universe and capturing them up close is extraordinarily complicated because they blind all contemporary instruments.
A quasar is a very bright nucleus of a galaxy. Its name is short for “quasi-stellar radio source” because it emits strong radio waves. Until the 1960s, astronomers thought they were bright stars, but details in their spectroscopy confirmed that they were at great distances, huge, sending powerful signals and varying their luminosity rapidly.
Today, astronomers know that the characteristic luminosity of a quasar is due to the accretion disk that forms around a supermassive black hole. If the galaxy has enough matter in its center and the black hole is large enough, a spiral of extremely hot dust and gas will be generated in the process of “falling” into it. With temperatures exceeding millions of degrees Celsius, this material at the heart of the galaxy emits electromagnetic radiation at most wavelengths. These natural signals are the only thing that sensors on Earth capture.
Quasars are millions of light years away. The best “photos” of these events are actually interpretations of the radio waves they emit. Conventional images have so far only shown a bright spot without much detail. NASA describes attempts to observe a quasar with telescopes like trying to look at a car’s blinding headlight and tell if an ant is walking on it.
Return to the original quasar
Recently, the Hubble Telescope turned its lens toward quasar 3C 273, the first of its kind discovered in 1963. An international group of astronomers has used everything they have learned in optics over the past 50 years to make brightness corrections to the second telescope’s lens. NASA’s most powerful and visualize the surroundings of that quasar located 2.5 billion light years away. The research was published in the journal Astronomy & Astrophysicswhile the historic photo is already on the official site of the space agency.
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