Invisible astronomy
Since the invention of the telescope, the human eye-opening observation of celestial bodies, study of the universe has entered a rapid period of time. By the late 20th century, people began to use objects to study cosmic radiation, the universe is the real door completely open. Celestial bodies will release electromagnetic radiation, the radiation is only a small part in the form of visible light, most of it is invisible. Such as gamma rays, x-ray, ultraviolet, infrared and radio waves. The radiation carries a variety of information objects, walking through the speed of light in the universe, after thousands of years to Earth. As the Earth's atmosphere, absorption, most of them can not reach the ground. With the scientific and technological progress, human beings can use the equipment on the ground to receive the radiation, can also avoid the use of satellite receiving the lower atmosphere cosmic radiation. Now, in addition to the traditional optical astronomy, but also the emergence of infrared astronomy, radio astronomy, UV astronomy, x-ray astronomy, gamma-ray astronomy. These are collectively referred to as non-visible light astronomy. If our eyes can see the radiation, then the sky will not only make us feel strange, but also make us very wonderful surprise colorful universe.
Galaxy dust filled the air, it makes visible light is difficult to walk through. The infrared can penetrate the interstellar dust has been. All stars in the universe than the average temperature (3000 degrees Celsius) are low objects emit infrared. Not only with infrared telescopes to see more objects, but also "aware" of their hot and cold. From 30 degrees to minus 250 degrees stellar dust clouds, can distinguish.
In contrast, the radio telescope is not so straightforward. It's that big plate-like antenna to the things we can not directly see what needs to go through computer processing can be converted to electronic images. But their ability is great, even more than the Hubble Space Telescope. It also ranked up a lot of this antenna, so that they work together. This can be better observed. U.S. specialty Baseline Array actually across the country. People use radio telescopes to study supermassive black holes spiral around the magnetic field, high energy, big explosion, and even track the molecules in space, that the new planets and life of the raw materials.
The universe has a lot of hot stars than the sun, they are more than 10,000 degrees Celsius, given the strong ultraviolet radiation. Study of these objects is inseparable from the ultraviolet telescope. Ultraviolet telescope can see the stars, while those between the hot gas is not visible, analyze what they are material. Of course, not only study the stellar ultraviolet telescope, can see ultraviolet telescope to Earth. Only in the ultraviolet telescope, we see the color of things is always strange, if not expertise, we can not see what tricks come. Because the Earth's atmosphere will block UV rays, ultraviolet telescope to use the satellite to bring it to the day.
x-ray is a high-energy electromagnetic radiation, only objects more than 1 million degrees Celsius until the release of these rays, that can bring high energy, highly penetrating, so the hospital will give patients x-rays. X-ray telescope at the sky, full of shiny things, a block of gas clouds, flickering dolphin x-ray star. The sun can also send x-ray, but more than 1 million degrees Celsius compared to those objects to, it becomes very weak. Thus, x-ray telescopes can see the universe in many hot spots, such as supernova remnants, pulsars surrounding gas, as well as black holes, their temperatures as high as 100 million degrees Celsius, is a very powerful x-ray source.
(Photo below) the middle of the bright part of the figure is quasar 3c279, this is a band from the observed gamma-ray images, the same as most of the quasars, 3c279 very dark, the sky in visible light, it is only a star-like points of light. In the gamma-ray telescope, 3c279 is a very bright sky. |
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