RATAN 600: purpose and principle of operation

2024 Author: Henry Conors | [email protected]. Last modified: 2024-02-12 02:55

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 m2. The telescope was created to study planets, the Sun, galaxies, extragalactic objects, spectral radiation 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 vital since the 50s. Initially, an experimental Pulkovo telescope was created, on the basis of which the effectiveness of variable profile antennas for space research was proved.

It was during the Cold War, when the rivalry between the US and the USSR heated up to the limit. The leadership, inspired by the launch of the first satellite, demanded (to the delight of scientists) to consolidate the success by building grandiose objects for space exploration. They were the unique six-meter mirror azimuthal telescope BTA and the radio telescope RATAN-600. The project was finally approved on August 18, 1965.

By the summer of 1974, the northern sector was commissionedreflector and irradiator No. 1. The first radio source PKS 0521-36 was investigated on July 12, 1974. By the beginning of 1977, the remaining parts of the complex were introduced: a flat reflector, southern, eastern and western sectors.

Description

The RATAN-600 telescope is operated by the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO), the only world-class observatory in the Russian Federation. 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 a total facility area of 15000 m² the antenna itself (outer part) only occupies 3500 m^{2. The inner part is an open space where emitters are placed, various devices that receive and analyze cosmic radiation.}

The RATAN-600, whose photo is impressive, was installed on the southern outskirts of the Zelenchukskaya village (Karachay-Cherkessia). The observatory settlement, which includes laboratory buildings, residential buildings, and a school, is located on the banks of the Bolshoi Zelenchuk River near the Nizhne-Arkhyz settlement of the 9th-13th centuries.

Specifications

The RATAN-600 uses new principles of telescope construction: altazimuth mount, aperture synthesis and controlled surface. Key Features:

• Frequency range: 610-30000 MHz.
• Wave range: 1-50cm
• Accuracy: 1-10 arcseconds.
• Angular maximum resolution: 2ang. sec.
• Brightness temperature detection limit: 0.050 mK.
• Flux density limit: 0.500 mJan.

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

Receiving booths

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

Cabins are placed on railway platforms, which allows them to be moved along 12 radial tracks. Mobility provides research of objects at different azimuths with a step of 30°.

Scientific work

A wide program of various researches is being implemented in SAO, including:

• Comprehensive study of solar activity in the radio band.
• Astrometry with the ultimate angular resolution (speckle interferometry) of binary and multiple stars and individual stars with extended atmospheres.
• High-resolution spectroscopy of the atmospheres and winds of stars of various types (in particular, the complex has become the main supplier of measurements of the magnetic fields of stars).
• Radio and optical spectroscopy of nebulae in our and other galaxies.
• Photometry with ultimate temporal resolution of relativistic objects (pulsars, black holes, etc.).
• Moderate and low resolution photometry and spectroscopy of microquasars, gravitational lenses, normal and peculiar galaxies and individual starsin them.
• Building a spatial and kinematic picture of the 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 instruments of open collective use. 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

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

In particular, the drive equipment of the secondary irradiators RATAN-600 was re-equipped and an automated control system for the positioning of the irradiators was introduced. Since 2008, a new version of the High Resolution Solar Spectral Polarization Complex (SPKVR-2) has been operating.

An Internet resource has been developed to present solar observation data, which collects and analyzes data in real time. It has services for searching and analyzing data, including comparison with data from other instruments, obtaining spectra and other parameters from local sources.

Work continues on the use of primary feeds with a single phase center, which allows“unload” the primary focus and conduct observations in the multi-frequency tracking mode (Oktava project for feeds No. 1 and No. 3).electromagnetic interference of radiometers in this range.

Advanced Research

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

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

Benefits

Among the advantages of the Russian telescope, experts highlight:

• a large aberration-free field;
• multi-frequency measurements (0.6-35GHz);
• increased resolution;
• increased brightness temperature sensitivity.

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

Despite its considerable age for a complex technical object, RATAN-600 continues to be the largest radio telescope in terms of area. It competes with the latest Chinese FAST complex with a five-hundred-meter aperture.