RATAN 600: purpose and principle of operation

RATAN-600 is the largest radio telescope in the world, located in Karachay-Cherkessia. The main mirror has a diameter of 576 meters, and the geometric area of the antennas is 15,000 m ² . The telescope is designed to study planets, the Sun, galaxies, extragalactic objects, spectral radiations and other purposes.

History: RATAN-600

The idea of building a domestic radio telescope based on the work of S. E. Khaikin and N. L. Kaidanovsky has been in existence since the 1950s. Initially, an experimental Pulkovo telescope was created, on the basis of which the effectiveness of variable-area antennas for space research was proved.

It was the time of the Cold War, when the rivalry between the US and the Soviet Union was heating up to the limit. The guidance, inspired by the launch of the first satellite, required (to the delight of scientists) to consolidate success by building grandiose objects for space exploration. They are a unique six-meter mirror azimuth telescope BTA and radio telescope RATAN-600. The project was finally approved on 18.08.1965.

By the summer of 1974, the northern sector of the reflector and the irradiator No. 1 had been delivered. The first radio source PKS 0521-36 was investigated on 12.07.1974. By early 1977, the rest of the complex was introduced: a flat reflector, a southern, eastern and western sector.

Description

The RATAN-600 telescope is operated by the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO), the world's only observatory in Russia. The object is equipped with a 576-meter ring antenna (circular reflector), consisting of 895 elements. The size of each receiving element is 2 m wide and 11.4 m high.

Out of the total area of the facility of 15,000 m ^{2, the} actual antenna (external part) occupies only 3500 m ² . The inner part is an open space where radiators are placed, various devices that receive and analyze cosmic radiation.

RATAN-600 was installed, the photo of which impresses, on the southern outskirts of Zelenchukskaya village (Karachay-Cherkessia). The settlement of the observatory, which includes laboratory buildings, residential buildings, a school, is located on the bank of the Bolshoe Zelenchuk River near the Nizhny-Arkhyz settlement of the 9-13th centuries.

Specifications

The RATAN-600 uses new principles of telescoping: altazimuth mount, aperture synthesis and controlled surface. Main characteristics:

• The frequency range is 610-30000 MHz.
• Wave range: 1-50 cm.
• Accuracy: 1-10 arc seconds.
• Angular maximum resolution: 2 ang. Sec.
• Limit of determination of brightness temperature: 0.050 mK.
• Limit of determination of the flux density: 0.500 mezhanskih.

Thanks to the team of researchers who create and constantly improve these devices, the complex remains a key element in the observation of the cosmos.

Reception cabins

In addition to a circular reflector that collects and concentrates information (radiation), RATAN is equipped with five reception cabins. They contain recording instruments.

The cabs are placed on railway platforms, which allows them to be moved along 12 radial routes. Mobility provides exploration of objects at various azimuths in 30 ° increments.

Scientific work

The CAO implements a wide program of various studies, including:

• A comprehensive study of solar activity in the radio range.
• Astrometry with the limiting angular resolution (speckle-interferometry) of double and multiple stars and individual stars with extended atmospheres.
• High-resolution spectroscopy of atmospheres and winds of various types of stars (in particular, the complex became the main supplier of measurements of magnetic fields of stars).
• Radio and optical spectroscopy of nebulae in our and other galaxies.
• Photometry with the maximum time resolution of relativistic objects (pulsars, black holes and others).
• Photometry and spectroscopy of moderate and low resolution microquasars, gravitational lenses, normal and peculiar galaxies and individual stars in them.
• Construction of a spatial and kinematic picture of a local group of galaxies.
• Photometry and spectroscopy of optical components of gamma-ray bursts at cosmological distances.
• Radio mapping of the relic background of the universe.

RATAN-600 (Zelenchuk) has the status of open-access tools. Along with domestic astronomers, a significant part of the observational time is allocated to foreign colleagues, as a rule, for the implementation of joint projects.

Modernization

Over the years of the existence of the CAO, a unique collective of instrumentation astronomers has been formed in it. Over the past decade, experts have re-equipped the telescope with radiation receivers with high and constantly increasing characteristics: sensitivity, spectral, spatial and temporal resolution.

In particular, the drive technology of secondary irradiators RATAN-600 has been re-equipped and a system of automated control of the positioning of irradiators has been introduced. Since 2008, a new version of the solar high-resolution spectral-polarization complex (SPKVR-2) is operating.

To represent the data of observations of the Sun, an Internet resource is developed, which collects and analyzes data in real time. It has services for searching and analyzing data, including matching with data from other tools, obtaining spectra and other parameters of local sources.

Work continues on the use of primary irradiators with a single phase center, which allows to "unload" the primary focus and conduct observations in the mode of multifrequency tracking (the Octave project for irradiators No. 1 and No. 3).
Work is underway to monitor and investigate external interference in the decimeter range, followed by the finalization of receiving paths for protection against electromagnetic interference from radiometers of this range.

Prospective studies

CAO oversees research programs designed to shed light on the riddles of the universe. Among the main projects:

• Studies of the Sun.
• Structure and kinematics of interstellar gas in star formation regions.
• The activity of sources of extragalactic radio emission.
• Search for relativistic jets in active galaxies and quasars.
• Investigation of the structure and kinematics of interstellar gas in the regions of star formation.
• Studies of spectra of extragalactic proto-objects.
• Cosmological gene.
• Observations on the Matrix Radio Engineering System MARS-3.
• Multiwave observations of the LSI + 61 303 object.
• Investigation of the spectra and variability of GPS sources.
• Simultaneous spectra of lacertides.
• Monitoring of microquasars.

Benefits

Among the advantages of the Russian telescope specialists distinguish:

• Large area of aboriginal field;
• Multifrequency measurements (0.6-35 GHz);
• Increased resolution;
• Increased sensitivity to brightness temperature.

In the coming years, RATAN will become even better: the Ministry of Education and Science of the Russian Federation in 2015 decided to allocate about 100 million rubles for the installation of mobile modules. If now the radio telescope observes objects in line of sight, then after modernization it will be able to accompany the target being investigated. This unique opportunity will expand the functionality of the complex.

In spite of its age, RATAN-600 continues to be the largest radio telescope in terms of area. The competition is made by the newest Chinese complex FAST with a five hundred meter aperture.