In China finally commissioned the largest and most sensitive single radio telescope the world. He promises to reveal many secrets of the Universe.
Birth of a giant
we are Talking about the tool FAST. This is the acronym for Five hundred meter Aperture Spherical Telescope, i.e. “Spherical radio telescope with an aperture of patisamerica”. This is a huge “plate” with a diameter of 500 meters, located in a natural karst depression.
By area, FAST holds the world record, ahead of such major instruments as the American Arecibo (diameter 300 metres) and BSA (sizes 200 and 400 meters). And since the sensitivity of the radio telescope is directly proportional to its area, it FAST became the most sensitive in the world. In other words, it is able to detect very dim objects.
In this FAST accepts radiation in a huge range of wavelengths: from 10 cm to 4.3 m. Thus it covers a significant portion of the range of radio waves transmitted to the earth’s atmosphere: from fractions of a millimeter to a few tens of meters.
the telescope Mirror consists of 4500 individual cells. This structure allows you to subtly adjust its shape to compensate for various deformation.
Construction of the facility began in 2011. 2016 test carried out observation. So a few days ago, the telescope was finally put into operation. According to the Agency “Xinhua”, all the technical parameters of the telescope has reached the target level or exceeded it.
According to the material edition of Universe Today, in 2020-2024 years FAST will review the entire available area on the sky. In his view gets numerous quasars, radio galaxies, neutron stars, cosmic masers, and so on.
in this review will spend half of the observing time of the telescope, and the other half will be allocated under other tasks. Will tell you more about them.
Maps of matter in the Universe
Almost 80% of atomtion of nuclei in the Universe accounts for the intergalactic gas, and 10% on interstellar. That is, the task is to map the distribution of atoms in the Universe basically boils down to mapping the intergalactic gas. The last 75% is hydrogen and 23% – from well-mixed with helium.
fortunately for astronomers, the hydrogen atoms emit radio waves with a length of 21 centimeters. Therefore, the extreme sensitivity will allow FAST to build large-scale maps of the distribution of matter in a large part of the observed space.
this information allows the check of model of expansion of the Universe and the theory of gravity, to clarify ideas about dark energy, and perhaps even more dimensions.
for More detailed maps FAST build for the Local group of galaxies. Among other things, this will allow us to test our ideas about the nature of dark matter.
please Explain. It is believed that dark matter under its own gravity gathered the germs of modern galaxies. Her attraction to accumulate around these clumps of gas, which eventually formed stars.
Here lies the problem. According to the model of cold dark matter (the most popular among professionals), the Local group should be formed of several thousand galaxies. Observed only about twenty. Where’s the rest?
There is a hypothesis that everything else is dark galaxy. The so-called hypothetical galaxy in which stars are generally not formed due to too low density. Such systems consist of dark matter and its gravity pulled gas, mostly hydrogen.
While the dark galaxy is only a figment of the theoretical constructs. Found only a few systems, extremely poor stars. However, the sensitivity of the FAST should be enough to locate in a Local band legions of these galaxies-ghosts. Just a few minutes of signal accumulation will be enough to find a cloud of atomic hydrogen with a mass of ten thousand suns.
If same observations show that in the Local group, there are no dark galaxies in the right amounts, scientists will have to revise their ideas about the nature of dark matter.
a Giant telescope mirror set in natural karst depression.EPA photo.
Space beacons
it is Expected that the FAST will help open a lot of radio pulsars. talked in detail about them. Recall that a neutron star emitting radio waves of a narrow beam.
According to theoretical estimates, in the Galaxy of a billion neutron stars, including up to 200 million active pulsars. At the same time, observers were still known only about three thousand of these amazing objects.
Even in a test observation in which FAST was in 2016, he helped to open 102 new pulsar. This is more than found during the same period, all the research groups from Europe and the United States all the instruments.
experts believe that years of work in the full mode, the new telescope will be enough to open about a thousand new neutron stars.
Lasers and molecules
Another intriguing class of objects – cosmic masers, natural radiolucency. The mechanism of the masers in the milky Way more or less understandable to specialists, although we need to clarify a lot of details. But extremely powerful megamasers, flashing in the cores of other galaxies, is virtually Terra Incognita. Although these objects has been known for about 40 years, the astronomers still do not know what processes lead them into action.
Scientists hope that the FAST will help to shed light on this mystery. In particular, he has a chance to become the first telescope, discovered megamaser on the basis of the methanol (while this molecule has shown itself only on a more modest masers).
speaking of molecules. The range of the telescope, the spectral lines fall 14 mAlakul. In particular, the huge instrument sensitivity will allow to search in the Galaxy of complex organics. A similar observation should give valuable information about the exotic chemistry of the interstellar medium. It is here, perhaps, lies the key to the origin of life .
Along with all the East
Finally, the FAST can be a broad-based network of radio telescopes, working together as a single instrument (the radio). Such systems provide a huge resolution (ability to distinguish fine detail). For example, such a network allowed in 2019 to get a long-awaited portrayal of a black hole.
Typically in such a scheme is the major the main telescope, and others work as support elements. All tools should be, quite simply, one side of the globe.
In the case of “portraiture” of a black hole the first violin playing the instrument ALMA, located in Chile. So the network could only be enabled telescopes in the Western hemisphere.
FAST can become the center of the interferometer, which will bring together Chinese, Indian, Japanese and Russian radio telescopes. To it can connect and tools Eastern Europe. New large-scale interferometric system can also present humanity with numerous astonishing discoveries.
Text: To.Science