Scientific achievements. Hardware and methodological developments
2024
Development of a Photodetector System Optimized for Photometry Methods Based on a Large-Format CMOS Photodetector
A large-format high-speed photodetector system (PDS) based on a back-illuminated CMOS photodetector GSENSE6060BSI (GPixel, China) with a 6K×6K-element format and a diagonal of 86.8 mm has been developed and manufactured to use at telescopes of SAO RAS and other observatories. The detector is located in a vacuum gaseous head at atmospheric pressure. Due to the antireflective coating of the photodetector, the PDS provides high quantum efficiency of detection of more than 95% at the peak sensitivity at a wavelength of 580 nm. The system ensures high accuracy in maintaining the temperature of the photodetector at a level of ±0.1°C, which allows stabilizing the gain of the video channel (gain instability is 0.064%). The camera cooling system is built on thermoelectric modules and includes air cooling with the possibility of using a liquid heat exchanger. The PDS controller implements the mode of simultaneous image reading in two 12-bit video channels with different gain and their subsequent combination into one frame with an extended 16-bit dynamic range (HDR, High Dynamic Range). The improved combination of frames with high and low gain into an HDR frame ensures the linearity of the “light-signal” transfer characteristic without gain shifts and dispersion at the junction of video channels. The implemented HDR frame mode (necessary for photometry of weak objects) ensures a high dynamic range and nonlinearity of the video channel of 0.69% and has no analogues among photoreceiving systems (of other manufacturers) available for purchase in the Russian Federation. The read images contain geometric noise caused by interference from the operation of the multiplexer control signals and the heterogeneity of numerous readout channels. Real-time frame correction methods allow minimizing geometric noise to values comparable to CCD photodetectors. For the use of PDS in long-exposure photometry methods, modes of dark current reduction, built-in zero subtraction, and video channel gain stabilization are provided. It is also possible to use PDS in fast spectroscopy methods, as part of adaptive optics systems, and fast sky surveys.
Authors:
Afanasieva I.V., Murzin V.A., Ardilanov V.I., Ivaschenko N.G., Pritychenko M.A. (SAO RAS)
Published:
1. Vlasyuk V.V., Afanasieva I.V., Ardilanov V.I., Murzin V.A., Ivaschenko N.G., Pritychenko M.A., Dodonov S.N., Large-format imaging systems based on solid-state detectors in optical astronomy, Uspekhi Fizicheskikh Nauk, 194, 432–445 (2024), doi: 10.3367/UFNr.2023.04.039575
2. Afanasieva I., Murzin V., Ardilanov V., Ivaschenko N., Pritychenko M., Large-format photodetecting system pCam6060 with a GSENSE6060BSI CMOS detector, developed at SAO RAS and optimized for photometric methods, Modern astronomy: from the Early Universe to exoplanets and black holes, Proceedings of the VAK-2024 conference, Aug 25–31, 2024 — Moscow, RIOR, 2024, ISBN 978-5-369-02160-6
2023
EXPLANATION: Exoplanet and transient events investigation project, first results
Amid the global boom of recent decades, programs of searching for and investigating extrasolar planets (exoplanets) in Russia were until recently extremely limited due to the lack of adequate scientific instruments. With funding from the Russian Science Foundation and two grants from the Ministry of Education and Science (2014-2022), SAO RAS created a complex of wide-angle robotic telescopes to search for exoplanets and non-stationary (transient) events, and a high-accuracy planetary spectrograph that allows detecting the radial velocity variations of parent stars under the influence of exoplanets. As a result, the project abbreviated as EXPLANATION (EXoPLANet And Transient events InvestigatiON) started in the Special Astrophysical Observatory of the Russian Academy of Sciences. Its goal is a massive search and study of exoplanets and non-stationary events in the Universe. In less than two years, the first ten exoplanets and exoplanet candidates were discovered within the project and studied using photometric transits and Doppler spectroscopy methods. An example of two such events is shown in Fig. 1.
Authors:
Valyavin G.G., Valeev A.F., Beskin G.M., Fabrika S.N., Galazutdinov G.A., Vlasyuk V.V. in cooperation with Yakovlev O.Ya. (SAO RAS, IKI RAS), Tavrov A.V., Korablev O.I. (IKI RAS).
Published:
1. Doppler confirmation of TESS planet candidate TOI-1408.01: grazing transit and likely eccentric orbit, Galazutdinov G.A., Baluev R.V., Valyavin G. et al, Monthly Notices of the Royal Astronomical Society: Letters, Volume 526, Issue 1, pp. L111-L115, DOI: 10.1093/mnrasl/slad127.
2. Eight Exoplanet Candidates in SAO Survey, Yakovlev O.Ya., Valeev A.F., Valyavin G.G. et al., Astrophysical Bulletin, Volume 78, Issue 1, p. 79-93, DOI: 10.1134/S1990341323010108.
3. Exoplanet Two-Square Degree Survey With SAO RAS Robotic Facilities, Yakovlev O.Ya., Valeev, Azamat F., Valyavin, Gennady G., Tavrov, Alexander V. et al. Frontiers in Astronomy and Space Sciences, vol. 9, id. 903429, DOI: 10.3389/fspas.2022.903429.
4. EXPLANATION: Exoplanet and Transient Event Investigation Project – Optical Facilities and Solutions, Valyavin G., Beskin G., Valeev A., Galazutdinov G. et al. Photonics, Volume 9, Issue 12, id. 950, DOI: 10.3390/photonics9120950.
Blazar classification based on multiparameter cluster analysis
Implementing multiparameter cluster analysis for the blazars from the Roma BZCAT catalog, we developed their classification that reflects a continuous variation of properties from the BL Lac-type objects to flat-spectrum radio quasars (FSRQs).
Using world-best databases as well as multi-frequency measurements obtained with RATAN-600, we selected a set of characteristics that described the spectral energy distribution from radio waves to gamma rays, radio luminosity, and distance to a blazar. With these characteristics we carried out a multiparameter cluster analysis using two machine learning methods, which showed similar (~90%) results.
The resulting classification is validated by comparison with the known blazar types: BL Lacs, FSRQs, high synchrotron peaked blazars (HSPs), and blazars detected in the TeV range. A continuous variation of properties along the obtained groups is observed. The group of HSP blazars stands out against the overall distribution.
On this example of a sample of blazars, we demonstrate the effectiveness of the clustering technique for objective analysis of multiparameter arrays of experimental data.
Authors:
Kudryavtsev D.O., Sotnikova Yu.V., Stolyarov V.A., Mufakharov T.V., Vlasyuk V.V., Cherepkova Yu.V. (SAO RAS).
Published:
Kudryavtsev D., Sotnikova Y., Stolyarov V., et al., 2023. Acta Astrophysica Taurica, vol. 4, no. 3, pp. 5–10. DOI: 10.34898/aat.vol4.iss3.pp5-10.
2022
Increasing the accuracy of measurements in the long-term accumulation mode at the RATAN-600
The mode of guidance of radio sources using a large reflection radio telescope can significantly expand the capabilities of the instrument both for studying the dynamics of variable objects and for implementing time accumulation in problems requiring high sensitivity. To implement the tracking modes of the RATAN-600 radio telescope, it is necessary to introduce new automation instruments that provide a new quality of monitoring and controlling the geometry of the antenna system [1], [2], [3]. To solve these problems in 2020-2022, an automated control system for the feed movement of type 3 was created and put into operation. The new automated control system ensures the normal operating modes of the feed, and also, due to the new possibilities for synchronous control of the movement of the carriage and the feed cabin, allows developing new methods of observing with the South+Flat antenna system. The structure of the automated control system is built using standard (widely available) instruments that support the most common industrial protocols for data exchange between the intelligent nodes of the complex, which makes it possible to expand the functions of the complex with low upgrade costs for fitting the automated control system with additional components of the distributed peripheral.
Authors:
Storozhenko A.A., Bogod V.M., Lebedev M.K., Ovchinnikova N.E., Khaikin V.B. (SAO RAS).
Published:
1. Storozhenko A.A., Lebedev M.K., Ovchinnikova N.E., Khaikin V.B. RATAN-600 Test Tracking Modes for Observations of Fast Variable Processes on the Sun // Solar-Terrestrial Physics: XXIII All-Russian Annual conf., Oct. 7-11 2019, Saint-Petersburg, Pulkovo: Proceedings — 2019. — Pp. 369-372. — DOI: 10.31725/0552-5829-2019-369-3722.
2. Storozhenko A.A., Lebedev M.K., Ovchinnikova N., Bogod V.M., Khaikin V.B., Ripak A.M., Pervakov A., Grechkin A. The Tracking Mode for the RATAN-600 Southern Sector with the Periscope // Ground-Based Astronomy in Russia. 21st Century: Proc. of the All-Russian Conf., Nizhny Arkhyz, Russia, September 21-25, 2020. — Pyatigorsk, 2020. — P. 407-408. — DOI: 10.26119/978-5-6045062-0-2 2020 407.
3. Storozhenko A.A., Bogod V.M., Lebedev M.K., Ovchinnikova N.E., Khaikin V.B., Pervakov A.A., Grechkin A.A. RATAN-600 receiving mirror automatic control system for tracking mode // Solar-Terrestrial Physics — 2021: XXV All-Russian Annual conf. in Solar Physics, October 4-8, 2021, GAO RAS, St. Petersburg. — 2021. — C. — 249-252. — DOI: 10.31725/0552-5829-2021-249-252. — (http://www.gaoran.ru/russian/solphys/2021/book/conf2021.pdf.)
2021
Achieving Record Resolution in Optical Astronomy by Observing Occultations of Stars by Asteroids
Observations of the occultation of the binary TYC 1947-290-1 by the asteroid (87) Sylvia at the 6-m BTA SAO RAS telescope made it possible to determine the diameter of the main component and set the upper limit for of the secondary. The measured angular values of the diameters of the TYC 1947-290-1 pair were 52 microseconds of arc for the bright (Vmag = 11.4) component and 31 microseconds as the upper resolution limit for the weak (Vmag = 12.1). Successful observations of the occultation by an asteroid in order to determine the angular diameter of the star were performed for the second time (the first by Benbow et al., 2019), with an optical telescope — for the first time. The obtained angular resolution is a record in the optical range and is comparable to the capabilities of modern radio interferometric complexes.
Our work has shown that observations of stellar occultations by asteroids can be used to measure angular sizes at a level of up to ≈30 microseconds of arc using single telescopes. This is tens of times better than the resolution of modern long-base interferometers in the visible and IR ranges and by three orders better than the diffraction limit of the largest optical telescopes.
Within the framework of the RFBR grant No. 20-32-70120 “Measurement of fundamental parameters of stars by high angular resolution methods”.
Authors:
Dyachenko V.V., Balega Yu.Yu., Beskakotov A.S., Maksimov A.F., Mitrofanova A.A. (SAO RAS) in cooperation with Richichi A. (INAF), Obolentseva M. (SPBU)
Published:
Dyachenko V., Richichi A., Obolentseva M., Beskakotov A., Maksimov A., Mitrofanova A., Balega Y., A joint occultation and speckle investigation of the binary star TYC 1947-290-1 and of the asteroid (87) Sylvia, 2021, Monthly Notices of the Royal Astronomical Society, 508(2), 2730-2735.
High Temporal Resolution Multimode Panoramic Photospectropolarimeter (MPPP)
The modernization of the instruments and software complex of the MANIA experiment for searching for and studying the variability of astrophysical objects with a temporal resolution of 10-6 s has been completed, the main component of which is the MPPP panoramic photopolarimeter which has no analogues in the world. As radiation receivers, two position sensitive detectors (PSDs) are used with the maximum sensitivity in the short-wave and long-wave regions of the spectrum (Debur et al., 2003; Plokhotnichenko et al., 2020) with the determination of the moments of detection of quanta by chronometric devices “Quantochron 4-48” (Plohotnichenko et al., 2009), as well as the EMCCD camera. The complex provides observations in the following 5 modes (with synchronous measurement of 3 Stokes parameters, if necessary): the broadband photometry with PSD and/or the EMCCD camera, synchronous UBVR photometry, spectroscopy with the Abbe prism (5 resolution elements), spectroscopy with the diffraction grating (50 resolution elements). They are changed remotely in 1-5 minutes, and the detection, storage, and reduction of data is provided by an information cluster consisting of 7 computers, which allows continuous recording photon fluxes throughout the night with an accuracy of 0.1 μs to UT. The results obtained during observations of X-ray sources, flaring stars, and optical pulsars demonstrate the efficiency of using the created complex in the high temporal resolution astronomy and relativistic astrophysics.
Authors:
Plokhotnichenko V.L., Moiseev S.V., Shergin V.S., Gorodovoy E.P., Gutaev A.G. (SAO RAS) in cooperation with Beskin G.M. (SAO RAS, KFU), Karpov S.V. (SAO RAS, Institute of Physics, Czech Academy of Sciences), V.G. de Bur (A.F. Ioffe Physical-Technical Institute of the Russian Academy of Sciences), Solin A.V., Solin A.A. (BSU Institute for Nuclear Problems, Belorus), Lyubetskaya Z.V., Lyubetskiy A.P. (LLC “Engineering Bureau TSEVLAP”, Pavlova V.V. (Rostov-on-Don), Moiseev S.S. (IE Moiseev), Badin D.A. (SAI MSU, Dukhov Automatics Research Institute (VNIIA), Plokhotnichenko P.V. (Service center Rus Lcd).
Published:
Plokhotnichenko V.L., Beskin G.M., V.G. de Bur, Karpov S.V., Moiseev S.V., Shergin V.S., Gorodovoy E.P., Gutaev A.G., Solin A.V., Solin A.A., Lyubetskaya Z.V., Lyubetskiy A.P., Pavlova V.V., Moiseev S.S., Badin D.A., Plokhotnichenko P.V., High Temporal Resolution Multimode Panoramic Photospectropolarimeter, Astrophysical Bulletin, 2021, Volume 76, No. 4, p. 558-576.
Interactive catalog of blazar measurements at RATAN-600
In 2021, an interactive catalog of multifrequency (1.1-22.3 GHz) measurements of blazars at the RATAN-600 was developed: “RATAN-600 multi-frequency catalog of blazars”. The catalog is hosted in www.sao.ru/blcat/ and is a modernized version of the electronic catalog of BL Lacertae objects (Mingaliev et al., 2014). The new catalog contains all types of blazars (blazars, flat-spectrum quasars, and blazars of an undetermined type) from the BZCAT blazar catalog (Massaro et al., 2009) and includes measurements of more than 1600 objects. The catalog contains the radio spectra and light curves of blazars obtained with the RATAN-600 SAO RAS in 2004-2021; measurements in the radio continuum from external sources connected from the CATS and NED databases are available for export. Basic information about objects (the coordinates, redshifts, blazar type, magnitude, and radio luminosity) is presented in the main table. Radio luminosities, spectral and variability indices, statistics on the main parameters of the sample are interactively calculated and available for export; objects with a radio emission variability of 200% at a frequency of 11 GHz on a scale of two years are indicated. The catalog is systematically updated with new measurements and is an effective tool for studying the statistical properties of large samples of blazars and for studying individual objects using long-term light curves.
Authors:
Sotnikova Yu.V., Mufakharov T.V., Mingaliev M.G., Udovitskiy R.Yu., Semenova T.A., Erkenov A.K., Bursov N.N., Mikhailov A.G. (SAO RAS).
Published:
1. Mufakharov T., Sotnikova Y., et al., The RATAN-600 multi-frequency catalogue of blazars, 2021, MNRAS, submitted.
2. Sotnikova Yu., Udovitsky R., Mufakharov T., state registration of the database “RATAN-600 multi-frequency data for blazars, edition 1.3”, Certificate No. 2021621910 dated 09.09.2021.
3. Sotnikova Yu., Mufakharov T., Udovitsky R. et al., Filing of an international application for the invention “Method of compiling a catalog of measurements of radio emission parameters of blazars”, Application No. PCT/RU2021/000473 dated 29.10.2021.
4. Mingaliev M., Sotnikova Yu., Udovitskiy R., et al., RATAN-600 multi-frequency data for the BL Lacertae objects, Astronomy & Astrophysics, 572, id. A59, 4 pp., 2014.
2020
Development of a high-speed image registration system based on a large-format low-noise CMOS photoreceiver
A high-speed image registration system based on a GSense4040CMT CMOS photoreceiver (GPixel, KHP) with a 4K×4K pixel format was developed and manufactured for the telescopes of SAO RAS. A new controller was developed allowing one to control the modes of operation and the thermal stabilization of the CMOS receiver, to form video data and transmit it to the control computer with a speed of up to 10 Gb/s. An effective set of programs for the class of high-speed photo receivers has been implemented. The main advantages of the developed CMOS system are the high frame readout rate (two orders of magnitude higher than the astronomical CCD systems), high sensitivity (comparable to CCD), and the large size of the receiver, which allows one to use the new image registration system for conducting quick sky surveys and obtaining images of rapidly varying astronomical objects. The developed system is expected to be used with the 6-meter BTA telescope for rapid spectroscopy.
Authors:
Murzin V.A., Ardilanov V.A., Afanasieva I.V., Ivashchenko N.G., Pritychenko M.A. (SAO RAS).
Published:
1. Afanasieva I.V., Murzin V.A., Ardilanov V.A., Ivashchenko N.G., Pritychenko M.A., Borisenko A.N., High-speed low-noise photoreceiving device for ground-based observation of space debris objects // all-Russian scientific conference “Space debris: fundamental and practical aspects of the risk”: proceedings. “Mechanics, control, and informatics” series, 2019, pp. 52-57.
2. V.I. Ardilanov, V.A. Murzin, I.V. Afanasieva, N.G. Ivaschenko, M.A. Pritychenko; “Development of Large-Format Camera Systems Based on the Latest Generation Sensors for the 6-m Telescope”; Ground-Based Astronomy in Russia. 21st Century, Proceedings of the All-Russian Conference held 21-25 September, 2020 in Nizhny Arkhyz, Russia. Edited by I.I. Romanyuk, I.A. Yakunin, A.F. Valeev, D.O. Kudryavtsev, 2020, p. 115-118.
2019
Wide-format CCD systems with high sensitivity in the red spectrum
Two cryostatic digital image recording systems based on wide-format thick-plate CCD photodetectors CCD231-84 (4128 × 4112 elements) and CCD261-84 (2080 × 4112 elements) (Teledyne E2V, Great Britain) were implemented and ready for operation at the BTA. The photodetectors are highly sensitive in the red and near-infrared ranges. In particular, at a wavelength of 900 nm, the quantum efficiency of the receivers is 60% (CCD231-84) and 90% (CCD261-84), compared to 30% for the thin CCDs that are currently used in BTA observations. The DINACON-5 last-generation universal controller is used in CCD systems, thanks to which a low readout noise (2.3 e−) is achieved, which is 20% better than the passport specifications. The high sensitivity of photodetectors in combination with low noise systems makes it possible to obtain more reliable observation data in the red region of the spectrum and to reduce the exposure time, which leads to saving the telescope time. The development and production of systems of this type at SAO RAS are unique in the Russian Federation. The performed work lays the foundation for the complete update of the BTA-telescope CCDs.
Authors:
Murzin V.A., Ardilanov V.I., Afanasieva I.V., Ivashchenko N.G., Pritychenko M.A., Borisenko A.N. (SAO RAS).
Published:
Ardilanov V.I., Murzin V.A., Markelov S.V., Afanasieva I.V., Ivashchenko N.G., Mitiani G.Sh., Pritychenko M.A., Borisenko A.N. A new generation CCD controller for the 6-meter telescope // Astronomy: Cognition Without Borders: Abstracts of VAK-2017, September 17-22, 2017, Yalta, Crimea, Russia, p. 33.
High-precision and quick alignment of large antenna surfaces
A high-precision method for the quick alignment of large antenna surfaces was developed and introduced in the standard mode using the example of geodetic alignment of the Southern sector and the RATAN-600 Flat reflector. The essence of the method is to fit the software and operating modes of the Leica TDRA6000 tacheometer to the conditions and surface requirements of the RATAN-600 radio telescope. The advantage of the method is the accuracy (0.5 arcsec, 0.2-0.35 mm in the center and at the edges of the sector, respectively), speed (2-3 hours), and large-scale measurements (up to 600 m). The method was effectively tested for the Southern sector and the RATAN-600 Flat reflector in 2019. The figure shows the measurement scheme of the radio telescope network and the state of some elements of the Southern sector during alignment. The method is also relevant for quick assessment of the state of the antenna surface.
Authors:
Zharov V.I., Boyko A.A., Kornienko I.B., Sotnikova Yu.V.
Published:
V. Zharov, Yu. Sotnikova; “Rapid Adjustment of Large Antenna Surfaces Using Modern Laser Systems”; Ground-Based Astronomy in Russia. 21st Century, Proceedings of the All-Russian Conference held 21-25 September, 2020 in Nizhny Arkhyz, Russia. Edited by I.I. Romanyuk, I.A. Yakunin, A.F. Valeev, D.O. Kudryavtsev, 2020, p. 428-431.
Development of a technique for applying reflective coatings to multi-purpose large-sized optical instruments
The results of the method of applying reflective coatings to multi-purpose large-sized optical instruments are presented. The technique was developed with reference to the VUAZ-6 vacuum chamber. In order to achieve repeatability of the result, total redesign of the camera evaporation system was carried out. Comparative characteristics of the technological processes are given. The results are presented as functions of the reflection coefficient of the BTA main mirror surface from the wavelength. We indirectly estimated the thickness of the obtained layers and their morphology. SAO RAS has the modern vacuum instrument which is unique in Russia used for applying reflective coatings on objects of various purposes with a diameter of up to 6 meters.
Authors:
Yakopov G.V.
2018
Introduction of Fast Radiometry at RATAN-600 for Studying Pulsar Radiation
The mode of fast radiometry with a discretization interval from 60 to 490 μs was implemented at the RATAN-600 radio telescope at a frequency of 4.7 GHz. For the first time ever, we detected single impulses from the close pulsar PSR0329+54 in the Southern sector and the young pulsar PSR0534+22 in the Crab Nebula in the Western sector. In the survey on the search for fast radio outbursts at the Western sector, we detected five single giant impulses (GI) from the 33-millisecond pulsar PSR0534+22 in the Crab Nebula at a multipath spectral complex with high temporal resolution in the 4.2-4.8 GHz frequency band. On June 30, 2018, the flow of GI (∼1 ms) exceeded 150 Jy, while the average impulse flows are below 10 mJy. From the time shift of the impulse arrival the dispersion was measured: DM = 57±1 pc/cm3 which is in good agreement with previous measurements. The GI detected in observations on October 2, 2018 consisted of two sub-impulses with a flux of about 8 and 4 Jy and a duration of 300 μs separated by 400 ms. It follows that the area of impulse radiation has a size of about 100 km, and its brightness temperature exceeds 1025 K. Using the fast radiometry mode and the “source-tracking” mode for 100-200 s will allow us to determine average fluxes and impulse profiles of pulsars at 4.7 GHz with the RATAN-600 radio telescope.
Authors:
Trushkin S.A., Tsybulev P.G., Bursov N.N., Nizhelskij N.A. (SAO RAS).
Integrated Information System to Maintain Observations at SAO RAS Telescopes
An integrated information support system for maintaining observatory telescopes has been implemented; it consists of the following web tools: submitting telescope-time proposals (Russian and English versions), scheduling observations (Russian and English versions) and supporting their archives, electronic observation logs with the report preparation on sets. The applications use a common database that stores information about applicants, observers, proposals, observation programs, etc. The applications support service functions for three groups of users in accordance with the roles assigned to them — “user”, “expert”, and “administrator”. This distributed system provides CSRFC/USI SAO RAS users with web interfaces to support individual stages of the observation cycle, provides increasing the efficiency of using telescopes operated by RTTAC. The development was carried out using the DBMS PostgreSQL and the perl, PHP, JavaScript programming languages including CSS.
Authors:
Vitkovskij V.V., Plyaskina T. A., Zhelenkova O.P., Shergin V. S. (SAO RAS).
2017
Photometer with the tunable filter for medium-sized telescopes
The Mapper of Narrow Galaxy Lines (MaNGaL) has been developed and manufactured. The instrument, the principle of operation of which is based on the use of the Fabry-Perot interferometer, allows us to obtain monochromatic images of galactic and extragalactic objects in different emission lines of ionized gas. It was successfully tested at the 1-m SAO RAS telescope and 2.5-m telescope of the Caucasian Mountain Observatory of SAI MSU.
Authors:
Moiseev A.V., Perepelitsyn A.E.
Published:
The result is presented at the VAK-2017 Russian conference: Perepelitsyn A.E., Moiseev A.V., “Optical reducer with the tunable interference filter for small- and medium-sized telescopes”.
New radiometric complex at RATAN-600 to observe fast radio bursts
A new radiometric complex for the range of 4.7 GHz has been developed and implemented at the RATAN-600 telescope of SAO RAS. The complex is designed for observations of fast radio bursts in the mode of the twenty-four-hour automatic sky survey. The standard radio survey of objects falling within the field of view is conducted simultaneously. The radiometric complex includes: 4 radiometers with the 600-MHz common band and division of the common band into 4 “narrow” contiguous subbands of 150 MHz each. The construction given allows one to reliably detect fast bursts from the outer space and separate them from local radio noise basing on radio wave dispersion in the interstellar medium.
Authors:
Nizhelskij N.A., Tsybulev P.G., Kratov D.V., Udovitskij R.Y., Borisov A.N., Fabrika S.N., Trushkin S.A., Fabrika S.N.
Published:
The result is presented at the VAK-2017 Russian conference: Tsybulev P.G., Nizhelskij N.A., Dugin M.V., Borisov A.N., Kratov D.V., Udovitskij R.Y., “New uncooled radiometric module of the 4.7 GHz to observe in the continuum”.
2016
Development and introduction into regular operation of the system for estimating the parameters of radio sources and monitoring of the parameters of antenna and receiving systems at the RATAN-600 radio telescope
The authors developed and put into operation the automated system of estimation the parameters of radio sources observed in the continuum radiometers of RATAN-600 (the total number of radiometers is 30). At the same time, the system is used for monitoring changes of the effective area of the antenna and the main lobe width of the beam pattern, as well as for monitoring the quality of receiving system operation. Development of this automated system was caused by the necessity to process a large volume of observed data — of the order of 40 thousand files in 30 days in the regular mode of radio telescope operation. The main advantage of the system is its speed and the possibility to control the performance at any stage.
Authors:
Udovitskij R.Y., Sotnikova Yu.V., Mingaliev M.G., Tsybulev P.G., Zhekanis G.V., Nizhelskij N.A. (SAO RAS).
Published:
1. Udovitskij R.Y., Sotnikova Yu.V., Mingaliev M.G., Tsybulev P.G., et al. Automated System for Reduction of Observational Data on RATAN-600 Radio Telescope, 2016, Astrophysical Bulletin, 71, 4, 532.
2. Udovitskij R.Y., Tsybulev P.G., Mingaliev M.G., Sotnikova Yu.V. The Research and Information System of Estimation of Parameters of Radio Sources in the Continuum with RATAN-600, Publications of the Institute of Applied Astronomy, issue 24, 277 (2012).
2015
Modernization of the BAO NAS RA 1-m Schmidt Telescope
The modernization of the 1-m Schmidt telescope of the Byurakan Astrophysical Observatory (NAS of Armenia) is finished. A new control system has been created, a CCD detector (4k×4k, readout noise of 11 e, pixel size of 9 μm (0.89 arcsec), field of view of about 1 sq. degree) with fluid cooling and a set of 21 midband, 5 broadband, and 3 narrowband filters has been installed in the telescope focus. First images have been received.
Authors:
S. Dodonov, V. Afanasiev, V. Amirkhanyan (SAO RAS) together with T. Movsessian, S. Balayan, V. Gabrielyan (BAO NAS RA).
The results were reported at the international conference “The Present and Future of Small and Medium-Size Telescopes” (SMT-2015), September 19-22, 2015, Nizhny Arkhyz.
1. V. Gabrielyan, T. Movsessian, Modernization of the Byurakan Astrophysical Observatory 1-m Schmidt Telescope, SMT-2015 Conference Abstracts, p. 36.
2. S. Dodonov, V. Afanasiev, V. Amirkhanyan, T. Movsessian, V. Gabrielyan, Spectrophotometry of Stars and Galaxies in Midband Filters with the Byurakan Astrophysical Observatory 1-m Schmidt telescope: the Instrument Possibilities and Challenges, SMT-2015 Conference Abstracts, p. 44.
2014
Development of Mini-MegaTORTORA (MMT) — a multichannel wide-field optical monitoring system with high temporal resolution
We have developed and put into operation a system that allows detecting and studying rapid phenomena with the localization in the near or far outer space unknown in advance. The MMT system is a robotic multichannel (9-objective) optical telescope with an approximate field of view of 900 square degrees and a temporal resolution of 0.1 seconds, equipped with a system of accumulation, analysis and storage of observed data. The MMT system has no analogues in the world in terms of its combined characteristics.
(Contact — Beskin G.M.).
Published:
1. Karpov S.; Beskin G.; Bondar S.; Perkov A.; Ivanov E.; Guarnieri A.; Bartolini C.; Greco G.; Shearer A.; Sasyuk V., Status and perspectives of Mini-MegaTORTORA wide-field monitoring system with high temporal resolution, EAS Publ.Ser., 2013, 61, 465.
2. G.M. Beskin, S.V. Karpov, V.L. Plokhotnichenko, S.F. Bondar, A.V. Perkov, E.A. Ivanov, E.V. Katkova, V.V. Sasyuk, A. Shearer, Wide-field subsecond temporal resolution optical monitoring systems for the detection and study of cosmic hazards, Advances in Physical Sciences, 2013, 183, 8, 4.
3. G. Beskin, S. Karpov, S. Bondar, A. Perkov, E. Ivanov, E. Katkova, V. Sasyuk, Mini-MegaTORTORA status update, Revista Mexicana de Astronomia y Astrofisica (Serie de Conferencias), 2014, Vol. 45, pp. 20-23.
MBLcat — a multi-frequency catalogue of RATAN-600 measurements for BL Lacertae type objects
We have compiled a multi-frequency catalogue of measurements for BL Lac type objects, based on the multi-frequency (1.1, 2.3, 4.8, 7.7, 11.2 and 21.7 GHz) RATAN-600 observational data. The distinctive feature of the presented observational data is the use of the same instrument for obtaining simultaneous multi-frequency measurements. The list of objects and the observed material is supplemented and updated by new and archived observational data. The catalogue can be found on the home page of the observatory: www.sao.ru/blcat/.
(Contact — Mingaliev M.G.).
Published:
M.G. Mingaliev, Yu.V. Sotnikova, R.Yu. Udovitskiy, T.V. Mufakharov, E. Nieppola, and A.K. Erkenov, RATAN-600 multi-frequency data for the BL Lac objects, 2014, A&A, 572, 59.
2013
A new control system for the 1-m telescope with remote control possibility for the observation process
In 2013, the creation of a control system for the multitask 1-m ZEISS-1000 telescope was completed in SAO RAS, allowing the use of the telescope's observational capabilities in the modes of local and remote control. Without stopping the instrument, the servo motors and position sensors on the telescope's axes were replaced. This allowed increasing the pointing accuracy of the telescope by several times (up to 5-7 for each axis) and improving the tracking quality. The use of intelligent digital drives connected via an industrial fieldbus made it possible to guide the telescope with varied speed when studying fast-moving objects.
(Contact — S.V. Drabek).
FITS 3.0-compatible archive of direct images with astrometric calibration
We used our program package to conduct mass corrections of the FITS-header keywords in accordance with the FITS 3.0 standard for all files (~120 thousand) of the local SCORPIO archive, which is included in the general observational data archive of SAO RAS. For direct SCORPIO images (~22 thousand frames), astrometric calibration based on the HST GSC, USNO-A2, 2MASS PSC, GSC-2.3 or SDSS-III catalogs was implemented with an accuracy of up to 0.2″. Based on the processing results, the local archive SCORPIO-C was created, which can be accessed from the web using the search system of the general observational data archive.
(Contact — V.V. Vitkovskij).
Published:
1. Zhelenkova O.P., Chernenkov V.N., Shergin V.S., Plyaskina T.A., Vitkovskij V.V. Software systems and information resources for facilitating astrophysical research. Infrastructure of satellite geo-information resources and their integration. Collection of scientific papers edited by M.A. Popov and E.B. Kudashev, Kiev, Carbon-Service, 2013.
2. Chernenkov V.N., Shergin V.S., Zhelenkova O.P. Technique of automatic coordinate calibration of direct images with the use of IVOA web tools. SAO RAS Report N329, 2013.
2011
Fiber Optic Echelle spectrograph
A high-resolution echelle spectrograph, designed for the fiber matching with the intermediate diameter telescopes (1-2 meters) was designed. In the range of 400-780nm 60 spectral orders are simultaneously recorded with the spectral resolution of R=30000. When tested at the 1-meter telescope of the SAO RAS, during a 1-hour exposure the signal-to-noise ratio S/N=10 was reached for the stars with mV=12.5. The first prototype was installed at the 1.2-m alt-azimuth telescope of the Kourovka Observatory.
In collaboration with the UFU.
(Contact — V.E. Panchuk).
Published:
Astrophysical Bulletin, 2011, vol. 66, 382.
On the improvement of the kinematics of the RATAN-600 reflecting elements
The RATAN-600 had the new kinematic mechanisms for the reflecting elements of the Northern and Southern sectors tested. It is shown that the application of modern kinematic components (the ball screws, CV joints, hybrid gearboxes), stepper and servo-controlled drives and encoders improves the accuracy of the panel positioning by the radius, angle, azimuth by 6, 4, 2 times, respectively, to reduce the backlash by 2-4 times, to shorten the panel setting time by 8-10 times, to achieve the repeatability of panel setting within 20 microns. The reliability of the kinematic mechanisms and the resource increase, while the energy costs are considerably reduced.
In collaboration with the North plant VNUTS, VTs Intex Retail.
(Contact — V.M. Bogod).
2009
Development of an Astrophysical Facility for the Studies of Fast Variable Processes
We finalized the development of a facility for observations (including remote observations) of the star-shaped objects with the temporal resolution of 1 micro second. The facility is featuring a multimode panoramic photospectropolarimeter, 1 or 2 coordinate-sensitive quanta detectors and a four-computer measurement control and registration system. Observational modes: photometric in the UBVR colour bands, spectral (50 or 10 nm per pixel), photopolarimetric and spectropolarimetric in 2 or 4 polarisation planes.
(Contact — G.M. Beskin).
RATAN-600 Multi-Octave Frequency Range Overlapping Finalized
We finalized the multi-octave overlapping of the RATAN-600 frequency range from 0.75 to 18GHz with the frequency resolution of 1% using the parallel spectrum analysing complex. In combination with large effective area, the RATAN-600 offers new opportunities of studying the thin structure of the solar corona radio emission. We have implemented the registration of the instantaneous spectra throughout the entire frequency range. Regular observations of the Sun go through an automated reduction and are available at http://www.spbf.sao.ru/prognoz/ within 4 minutes from the acquisition time.
(Contact — V.M. Bogod).
2008
New Fourier spectrum analyzer for radio astronomy research at the RATAN-600
A new digital Fourier spectrograph with the analysis bandwidth of 60 MHz and 2048 spectral channels was put into operation at the RATAN-600. Getting information about the studied signal in the time-frequency-power measurements allows recording and analyzing the signals, rapidly varying in time. The use of this device facilitates the separation of radio astronomical signals from noise — the registration of a broadband signal, divided into a large number of narrow areas provides the capability to eliminate the distortions, introduced by the interferences stable in frequency. The presence of information about the moment of registration in the recorded signal allows to exclude the short-term broadband spark-type interferences.
In collaboration with IAA, ASC LPI RAS, Institute of Isotherms.
(Contact — A.P. Venger).
2007
Accuracy of Radial Velocity Measurements Enhanced on BTA
As a result of usage of an absorption cell, the accuracy of measurements of Doppler shifts on BTA's stellar spectrographs was increased by more than an order (Δ Vr = 20-30 m/s).
Program for Finding Photometric Distances to Nearby Galaxies
A programme was elaborated to measure high-precision photometric distances to nearby (resolved into stars) galaxies according to the Tip of the Red Giants Branch (TRGB) method. The use of a maximum likelihood method and photometric accuracy assessment with an application of expanded statistical modeling of dense star fields allowed to increase the accuracy of distance finding using the TRGB method up to 5-8%, which is comparable to the accuracy of a Cepheid distance indicator. This method has no equal as of its versatility and short observation times.
Test Observations on RATAN-600 with MARS-3 16-Channel Matrix System
First observations were made on RATAN-600 with a unique MARS-3 16-channel (32 inputs) Matrix Radiometric System that has no analogue in Russian radio astronomy. The use of such system in a mode when radio sources propagate through a fixed diagram of the antenna, allows quadrupling of radiotelescope's sensitivity compared to one-channel radiometer and decreases the time of signal collection from weak objects by 16 times.
Centre for Analysis of Multiwave Observations Created on RATAN-600
An on-line processing centre for analysis of multiwave radio observations of the Sun on RATAN-600 was created in the St. Petersburg Branch of SAO RAS, see http://www.spbf.sao.ru/prognoz/. Its functions include automatic polling of multiwave length data from RATAN-600, all radioheliographs and satellite observatories; full data processing and correlation, and multi-format submission to the end users. The Centre is dedicated to the creation of a generalized forecast of solar activity based on detailed spectrum of radio frequency observations of the Sun and for students' labs.
2006
A high angular resolution (0.4") was reached at the BTA as a result of use of an image stabilizer, coupled with the optical image cutter and a specialized echelle spectra reduction algorithm during the observations with high spectral resolution (R = 75000) in the wavelength range of 450-650 nm. This made it possible to study the properties and spatial distribution of the circumstellar matter in objects, located in our Galaxy at the distances of about 2 kpc.
A method for suppressing the background noise of radio sources was developed and implemented at the RATAN-600, allowing to increase severalfold the penetrating ability of the major Russian shortwave radio telescope.
2005
Creation of the distributed net of control (DCN) of the 6 m telescope has been completed, which is based on the use of digital tracking drives and the means of commercial automatization to ensure the real-time processes of control and data acquisition. With changing to DCN, computer diagnostics of the majority of units of the telescope has been implemented, the reliability of its operation in the whole has been increased, its performance characteristics have been improved. The created original software permits flexible change and reconstruction of the telescope units and involve new service functions.
For the solar spectral-polarization complex of high resolution of RATAN-600 input feeds of circular polarization allowing measurement of extreme polarization degrees in a range of 6-18 GHz have been created. Data acquisition system for registering 64 channels with a speed of 1 millisecond per channel and software for reduction of multiwave observations allowing comparison with the data of the main ground-based and space solar observatories have been developed. Complete automation of the complex performance in the mode of adaptive selection of amplification, control of the current parameters, channel smoothing of a spectrum to an accuracy of 0.5% etc. have been implemented.
The first Russians Internet opened visual monitoring system is developed and put into operation for the SAO RAS 6 m telescope. That makes it possible for the operators and observers to inspect remotely the state and performance of the basic telescope systems, pointing control and weather conditions.
2004
Creation of a unique set of the spectral and polarization complex of high resolution in the range of 6-18 GHz, consisting of 64 channels with a 1% analysis stripe was concluded. Based on the combination of key parameters — the frequency overlap and resolution, sensitivity and accuracy of polarization measurements, such a complex is the first instrument of its kind in the practice of solar astronomy.
A new cryogenic radiometer with the sensitivity close to the limit on the surface of the Earth was developed, manufactured and implemented for normal observations at the RATAN-600. The radiometer operates at the dedicated frequency for the radio astronomy, 4.8 GHz (6.25 cm), uses both modes of circular polarization with a separate amplifier channel for each mode, and implements an additional gain in sensitivity owing to the absence of losses due to the splitting of circular modes in the aperture of the RATAN-600.
2003
As a result of development of image slicers, polarization analyzers and reduction technique, the limiting magnitude of spectral observations at BTA with high spectral resolution (up to R = 80000) has been increased by 3 times, the limiting magnitude of spectropolarimetric observations increased from 3 to 8 times (in the red and UV ranges, respectively).
A wide-angle system (18×20 degrees) of high time resolution (up to 0.13 s) for real time detection of variable astronomical objects — optical transients of gamma-bursts, flare stars and novae, supernovae at early stages of their birth, and also near-earths moving bodies of natural and artificial origin — is created.
In co-operation with Kosmoten and SRI RAS.
2002
A quartz echelle spectrograph with a large diameter of the collimated beam (NES) equipped with a CCD (2048×2048 elements) was designed, manufactured and put into operation in the Nasmyth focus of the 6-m telescope. The spectrograph provides the spectral resolution of up to R = 82000 in the wavelength range of 320-1000 nm. The information content of observations with high spectral resolution at the telescope is increased tenfold.
In collaboration with the University of Uppsala (Sweden).
A new-generation CCD system with the cryostat matrix detector sized 2048×2048 elements was designed and put into operation at the 6-m telescope. Digital video signal filtering and correction of the light transmission characteristics were implemented for the first time. This provides the limiting sensitivity and photometric stability for the astronomical practice. The readout noise is reduced by 30-40% compared with the traditional methods of data reduction (with the EEV CCD42-40 - 1.7 electrons). The residual nonlinearity does not exceed 0.03%, and relative photometric instability does not exceed 0.06% over 24 hours. Production of such systems with the CCD42-40 for the 6-m telescope is tailored.
In collaboration with the Institute of Applied Physics of the RAS.
We have developed and tested the model of a new-generation three-element broadband radiometric matrix system at the RATAN-600 extremely short wavelength of 1 cm, allowing a large replication to over 100 elements. The sensitivity of 6 mK reached without cooling is close to the sensitivity of the cryogenic radiometers of the RATAN-600 in the given range.
New electrodynamic calculations of the RATAN-600 power beam pattern, including the diffraction effects and the account of the finite size width of the primary mirror aperture are in good agreement with the experimental measurements over a wide wavelength range and a large solid angle, conducted in 2002. These measurements and the power beam pattern calculation programs increase the accuracy of measurements of the flux densities and radio brightness distributions of extended cosmic sources, and are used in the data processing and modeling of the recent and future radio surveys featuring the radio source counts, and in the studies of the anisotropy of the cosmic microwave background.
Creation of a basic high speed Ethernet information computer network of the SAO RAS has been accomplished. It now provides access to the BTA and RATAN-600 telescopes at 155 Mbit/s based on the 27 km-long fiber optic link. The outgoing Internet speed reached is 2 Mbit/s.
2001
A new-generation SCORPIO spectrograph was created for the primary focus of the BTA. It allows observations of extended and starlike objects in different modes: CCD photometry, panoramic spectroscopy with the Fabry-Perot interferometer, spectroscopy and spectropolarimetry with a “long-slit”, slit-free spectroscopy, multi-object spectroscopy. In the spectral observations mode the instrument is 5-6 times superior in the efficiency to the existing spectrographs of this class at the BTA and is comparable to the best world analogues.
The reconstruction of the azimuth axis drive of the BTA is completed. Digital servo drives that were installed have improved the reliability of the complex, extended the range severalfold, and reduced the telescope's speed control step. The implementation of such drives provides a basis for the distributed control system of the BTA complex.
A new system of automated control of the RATAN-600 flat reflector was put into operation. It allows to increase the productivity of its use by an order of magnitude and develop new observational modes. The mode of multi-azimuth observations using an automated flat reflector, the South sector and a high-precision digital drive of the receiving cabin irradiator 3 was implemented.
The work on improving the accuracy of the reflecting surface of the RATAN-600 antenna was completed. As a result, the standard error of individual reflecting elements was improved to about 0.2 mm.
A software and hardware set for the BTA control system was implemented. It allows for the network monitoring of the telescope in different modes, including the display of video from the guide and service camcorders of the BTA. Three types of interface were carried into effect: the user, operator and Web-interfaces.
A digital archive was compiled, covering the observations at the RATAN-600 in the continuum for over 23 years of operation.
1999
A new fiber multiobject spectrograph of the prime focus of the BTA was manufactured, designed for the spectroscopy of low and moderate spectral resolution of up to 70 objects at once, visible in the telescope's field of view sized 12'. A metalized mask was inserted in the focal plane of the telescope, where with the aid of magnets the quartz fibers were fixed, transmitting the light in the focal plane of the collimator in the shape of a long slit. The new spectrograph brought an opportunity to explore the objects with absolute magnitudes m = 22-23 in the R-band. In 1999 the spectrograph was used for the BTA observations within two programs.
After many years of work, the multi-frequency (matrix) radiometer with the fluctuation sensitivity above 10 mK/s at all operating channels was completed and turned into operation at the RATAN-600 radio telescope.
We have extended (20-fold in the analysis strip) the capabilities of extragalactic research at the RATAN-600 in the 21 cm line with the introduction of a 50 MHz spectrum analyzer operating on the principles of acousto-optics.
1998
Creation of the world's largest database of radio astronomical catalogs, designated CATS was completed, which is now free and available online at the web server cats.sao.ru. It includes the data of X-ray, optical, infrared and radio wavelength ranges on 4.5 million space objects from 300 catalogs (the radio astronomical catalogs were presented in full for the first time).
1997
The parameters of the unique solar complex at the RATAN-600 were enhanced. Determined by the unit's instrumental errors, the maximum accuracy of polarization measurements was reached on the panoramic spectrum analyzer PAS of the RATAN-600: 0.02-0.03% in the measurements over the entire solar disk, and 0.2-0.3% in the measurements of point sources. Automation of the complete cycle of solar observations with the RATAN-600 was finalized, with the daily multi-wavelength observational data outputs to the Internet via the SAO servers and SOHO satellite.
A coude-echelle spectrometer of high and very high resolution was designed and manufactured for the 2-meter telescope (Terskol peak) with the simultaneous spectrum registration in a wide wavelength range (3500-10000 A) by the CCD system. The spectrometer has three Schmidt cameras that enable spectral observations with the resolution of R = 45000, 90000, 180000. For a 10m star during the 1 hour exposure time, the S/N ratio equal to 100 is reached at R = 45000. By its main characteristics the instrument is comparable to the best world systems of the class, which allows solving a large variety of astronomical tasks in the spectroscopy at the contemporary level, requiring a high spectral resolution.
1996
The highly effective method controlling a wide class of radio interferences in the most sophisticated UHF band was put into practice of observations.
1995
A new-generation automated control system of the antenna in two sectors of the RATAN-600 circular reflector was put into regular operation. The reliability and dynamics of the system were increased by 10 times, while the accuracy and repeatability doubled. This allows measuring the flux densities of radio sources in the shortwave range with an accuracy of about 1%. In 1995, 8000 observations were made at the level of system failures of less than 0.2%.
Alignment and stabilization of the surface (225 elements) of the RATAN-600 northern sector were performed, resulting in the RMS surface accuracy increase from 1.0-1.3 mm to 0.18 mm. This has augmented the effective area of the northern sector by 70% at the wavelength of 1.38 cm. The achieved parameters improve the efficiency of the observing time usage at RATAN-600 in the shortwave range by several times.
1994
World-class sensitivity was reached at the RATAN-600 radio telescope in three centimeter wavelengths (2.7, 3.9, and 7.6 cm): 3.2, 3.4 and 2.5 mK/s, respectively through the introduction of cryogenic low-noise amplifiers based on the high electron mobility transistors (HEMT) in the radio astronomy observations.
A new-generation 2D-spectrograph featuring a CCD, mounted inside the high-aperture Schmidt camera was developed and put into service at the BTA telescope. In the visible spectral range (3000-10000 A) the quantum efficiency of 6-8% was reached, which corresponds to the world standards for the instruments of this type.
The prototype of the fluctuation damping circuit, which reduces the vibrations of the telescope in terms of the decay time by 5-6 times was developed and mounted at the BTA. The ability to create high-precision control systems for the BTA and other alt-azimuth systems with an order of magnitude higher precision characteristics under the wind loads on the telescope was experimentally demonstrated.
1993
We have mastered the technique of generating the secondary standards for the astrometric reference of images obtained using the CCDs at the BTA with the accuracy to one second of arc, based on the on prints from the Palomar maps using the Guide Star Catalog and a digitizer.
For the first time a device for quasi-simultaneous measurements of linear polarization of stars was developed, which allows to make up to 40% more efficient the use of the telescope time and significantly increase its accuracy. The device is protected by a patent.
Fast systems of high spectral resolution were developed and put into operation at the 6-m BTA and 1-m Zeiss telescopes, consisting of the echelle spectrometers, solid-body light detectors (CCDs), data acquisition and data processing systems. Judging on the basic photometric and positional features, the CEGS coude-echelle spectrometer is on par with the UCLES of the Anglo-Australian 3.9-m telescope and the Hamilton Echelle Lick (3-m telescope, U.S.), being second only in the CCD size. The echelle spectrometer, operating in the red band (“Lynx”) is not inferior to the CASPEC echelle spectrometer of the 3.6-m telescope of the European Southern Observatory based on its main characteristics.
The work on “cooling” the RATAN-600 has been accomplished. The flaps that reduce the contribution of the Earth below the temperature of the sky were installed. At the same time, the range was expanded up to 1.3 meters and the effective area at the decimeter waves was increased.
For the first time in radio astronomy observations in Russia a new type of amplifier (based on the HEMT transistor type) as part of the cryogenic radiometer at the 2.7 cm wavelength with a record sensitivity in this range of about 3 mK/s was introduced.
Archive