Since August 2014, a monitoring survey at a frequency of 111 MHz has been conducted on the Large Phased Array (LPA) radio tele-scope of the P.N. Lebedev Physical Institute (LPI). We report the discovery of a bright pulse having a dispersion measure (DM) equal to134.4 +/- 2pccm(-3), a peak flux density (S-p) equal to 20 +/- 4 Jy, and a half-width (W-e) equal to 211 +/- 6 ms. The excessive DM of the pulse, after taking into account the Milky Way contribution, is 114 pc cm(-3 )that indicates its extragalactic origin. Such value of DM corresponds to the luminosity distance 713 Mpc. The above parameters make the pulse to be a reliable candidate to the fast radio burst (FRB) event, and then it is the second FRB detected at such a large lambda similar to 2.7 m wavelength and the first one among non-repeating FRBs. The normalised luminosity L-nu of the event, which we have designated as FRB 20190203, estimated under assumption that the whole excessive DM is determined by the intergalactic environment towards the host galaxy, is equal to similar or equal to 10(34)erg s(-1)Hz(-1). In addition to the study of radio data we analysed data from the quasi-simultaneous observations of the sky in the high energy (>= 80 keV) band by the omnidirectional detector SPI/ACS aboard the INTEGRAL orbital observatory (in order to look for a possible gamma-ray counterpart of FRB 20190203). We did not detect any transient events exceeding the background at a statistically significant level. In the INTEGRAL archive, the FRB 20190203 localisation region has been observed many times with a total exposure of similar to 73.2 days. We have analysed the data but were unable to find any reliable short gamma-ray bursts from the FRB 20190203 position. Finally, we note that the observed properties of FRB 20190203 can be reproduced well in the framework of a maser synchrotron model operating in the far reverse shock (at a distance of similar to 10(15)cm) of a magnetar. However, triggering the burst requires a high conversion efficiency (at the level of 1%) of the shock wave energy into the radio emission.

ABSTRACT Studies of the pulsar B0823+26 have been carried out using the Large Phased Array (LPA) radio telescope. At a time span of 5.5 yr, the amplitudes of the main pulse (MP), postcursor (PC), and interpulse (IP) were evaluated in daily sessions lasting 3.7 min. It is shown that the ratio of the average amplitudes of MP in the bright (B) and quiet (Q) modes is 60. For B-mode, the average ratio of MP amplitudes to IP amplitudes is 65, and the ratio of MP amplitudes to PC amplitudes is 28. The number of sessions with a nulling is 4 per cent of the total number of sessions. Structure function (SF) and correlation function analysis of MP, IP, and PC amplitude variations of over a long-time interval allowed us to detect typical time scales 37 ± 5 d and one year. The analysis of time variations shows that the time scale of 37 d is well explained by refraction on inhomogeneities of interstellar plasma, which is distributed mostly quasi-uniformly in the line of sight. This scintillation makes the main contribution to the observed variability. Analysis of the structure function showed that there may be a few days variability. This time scale does not have an unambiguous interpretation but is apparently associated with the refraction of radio waves on the interstellar medium. One-year variability time scale has not been previously detected. We associate its appearance with the presence of a scattering layer on a closely located screen at a distance of about 50–100 pc from the Earth.

We report the discovery of a bright pulse having a dispersion measure (DM) equal to 134.4 ±2 pc cm^-3, a peak flux density (S_p) equal to 20 ±4 Jy and a half-width (W_e) equal to 211 ±6 ms. The excessive DM of the pulse, after taking into account the Milky Way contribution, is 114 pc cm^-3 that indicates its extragalactic origin. Such value of DM corresponds to the luminosity distance 713 Mpc. The above parameters make the pulse to be a reliable candidate to the fast radio burst (FRB) event, and then it is the second FRB detected at such a large λ∼2.7 m wavelength and the first one among non-repeating FRBs. The normalized luminosity L_νof the event, which we have designated as FRB 20190203, estimated under assumption that the whole excessive DM is determined by the intergalactic environment toward the host galaxy, is equal to ≃10^34 erg s^-1 Hz-1. In addition to the study of radio data we analyzed data from the quasi-simultaneous observations of the sky in the high energy (≥80 keV) band by the omnidirectional detector SPI/ACS aboard the INTEGRAL orbital observatory (in order to look for a possible gamma-ray counterpart of FRB 20190203). We did not detect any transient events exceeding the background at a statistically significant level. In the INTEGRAL archive, the FRB 20190203 localization region has been observed many times with a total exposure of ∼73.2 days. We have analyzed the data but were unable to find any reliable short gamma-ray bursts from the FRB 20190203 position. Finally we note that the observed properties of FRB 20190203 can be reproduced well in the framework of a maser synchrotron model operating in the far reverse shock (at a distance of ∼10^15 cm) of a magnetar. However, triggering the burst requires a high conversion efficiency (at the level of 1

At the LPA LPI radio telescope, a search was conducted for pulse signals in a specific area with declinations +52°δ+55°. The processing involved ten months of observations recorded in six frequency channels, each with a channel width of 415 kHz and a total bandwidth of 2.5 MHz. The analysis of the data revealed 22 000 events, exhibiting a pronounced dispersion delay of signals over the frequency channels, which are indicative of pulsar pulses. These pulses were found to belong to four known pulsars and two new rotating radio transients (RRAT). Additional pulse search was carried out in 32-channel data with a channel width of 78 kHz. This led to the discovery of 8 pulses for the transient J0249+52 and 7 pulses for the transient J0744+55. No periodic emission of transients was detected. The analysis of the observations indicates a high probability that the identified RRATs are pulsars with nullings, where the fraction of nullings is greater than 99.9%.

A search for pulse signals was carried out in a new sky area included in the monitoring program for the search for pulsars and transients. Processing of several months data recorded in six frequency channels with a total bandwidth of 2.5 MHz showed that, on average, 4 pulses per hour are observed in each of the 24 connected stationary beams. Of these pulses, 18.3% are similar to those of pulsars. They are visible in one or two neighboring beams and have a pronounced dispersion shift, that is, they are recorded first at a high and then at a low frequency, which indicates the possible passage of the signal through the interstellar medium. Almost 68% of such detected pulses belong to six known pulsars with dispersion measures from 9 to 141 pc/cm(3), and almost all of the remaining pulses are either noise of an unknown nature or artifacts of the proposed pulse separation technique. An additional study of the selected array of 3650 obvious pulsar pulses revealed 13 pulses belonging to four rotating radio transients (RRATs). Their dispersion measures are in the range of 17-51 pc/cm(3). A search for regular (periodic) RRAT emission was carried out using power spectra summed over 121 days. Periodic radiation was not detected, but for two RRATs, upper estimates of the periods were obtained from measurements of the time intervals between pulses. The upper estimates of the integrated flux density of the detected RRATs are in the range 2-4 mJy at the frequency 111 MHz.

We present our observations of electromagnetic transients associated with GW170817/GRB 170817A using optical telescopes of Chilescope observatory and Big Scanning Antenna (BSA) of Pushchino Radio Astronomy Observatory at 110 MHz. The Chilescope observatory detected an optical transient of ∼19 m on the third day in the outskirts of the galaxy NGC 4993; we continued observations following its rapid decrease. We put an upper limit of 1.5 × 10 4 Jy on any radio source with a duration of 10–60 s, which may be associated with GW170817/GRB 170817A. The prompt gamma-ray emission consists of two distinctive components—a hard short pulse delayed by ∼2 s with respect to the LIGO signal and softer thermal pulse with T ∼ 10 keV lasting for another ∼2 s. The appearance of a thermal component at the end of the burst is unusual for short GRBs. Both the hard and the soft components do not satisfy the Amati relation, making GRB 170817A distinctively different from other short GRBs. Based on gamma-ray and optical observations, we develop a model for the prompt high-energy emission associated with GRB 170817A. The merger of two neutron stars creates an accretion torus of ∼10 −2 M ⊙ , which supplies the black hole with magnetic flux and confines the Blandford–Znajek-powered jet. We associate the hard prompt spike with the quasispherical breakout of the jet from the disk wind. As the jet plows through the wind with subrelativistic velocity, it creates a radiation-dominated shock that heats the wind material to tens of kiloelectron volts, producing the soft thermal component.

In the process of astronomical observations vast amounts of data are collected. BSA (Big Scanning Antenna) LPI used in the study of impulse phenomena, daily logs 87.5 GB of data (32 TB per year). This data has important implications for both short-and long-term monitoring of various classes of radio sources (including radio transients of different nature), monitoring the Earth's ionosphere, the interplanetary and the interstellar plasma, the search and monitoring of different classes of radio sources. In the framework of the studies discovered 83096 individual pulse events (in the interval of the study highlighted July 2012 - October 2013), which may correspond to pulsars, twinkling springs, and a rapid radio transients. Detected impulse events are supposed to be used to filter subsequent observations. The study suggests approach, using the creation of the multilayered artificial neural network, which processes the input raw data and after processing, by the hidden layer, the output layer produces a class of impulsive phenomena.

Purpose: The goal of the work is to develop a workable technique for fast processing of large arrays of radio astronomy data to search for responses to extragalactic transient events, which a priori should have large dispersion (DM ~ 100÷2000 pc · cm-3). Records of 20-day continuous observations of the sky sphere circumpolar zone with an area of about 8 sq deg and separate files with repeating fast radio burst FRB 121102 were used as a test sample of the technique. Design/methodology/approach: The BSA (Big Scanning Antenna) LPI radio telescope has a multi-beam diagram and is capable of recording daily in the frequency range of 109–111.5 MHz in 96 beams in the declination range from – 8° to +42°. The number of frequency bands varies within 6 to 32 for the time constant varying within 0.1 to 0.0125 s, respectively. In the mode of recording 32 frequency bands with the time constant 0.0125 s, 3.4 GB of data are recorded every hour, 87 GB – daily, and 32 TB – per year. To end of August 2018, about 120 TB of data have been accumulated. Processing this amount of data for a number of scientific problems urgently requires the use of high-performance computing technologies. Findings: The paper proposes two ways to process data: using graphics processors (CPU+GPU, calculation in the C/C++ programming language using OpenCL) and using cluster computing (by using the message passing interface MPI on multiprocessor nodes). To refine the methodology, we use both the processing of pulsar data (using graphic accelerators allows us to increase the processing speed by 2–3 orders of magnitude) and search for responses to extragalactic transient events, which a priori should have large dispersion delays. Examples of such events include fast radio bursts (FRB), responses to gamma radio bursts (GRB) and, finally, possible responses to gravitational events recorded by the LIGO detectors. After processing the polar zone, 697 candidates for pulsed events with high dispersion measures were detected. About half of them is caused by man-made interference, the rest being caused both by the usual interplanetary scintillations of radio sources, and also by the possible soughtfor FRBs. It is still difficult to separate these two classes of events. Processing the data observed in the FRB 121102 zone also indicates the presence of event candidates. The results require more thorough analysis. Сonclusions: After finalizing the high-performance computing methodology, it will allow us to process data observed with the BSA LPI multipath diagram immediately after they are recorded.

We present the first VLBI observations of a Galactic water maser (in Cepheus. A) made with a very long baseline interferometric array involving the RadioAstron Earth-orbiting satellite station as one of its elements. We detected two distinct components at -16.9 and 0.6 km s(-1) with a fringe spacing of 66 mu as. In total power, the 0.6 km s(-1) component appears to be a single Gaussian component of strength 580 Jy and width of 0.7 km s(-1). Single-telescope monitoring showed that its lifetime was only eight. months. The absence of a Zeeman pattern implies the longitudinal magnetic field component is weaker than 120 mG. The space-Earth cross power spectrum shows two unresolved components smaller than 15 mu as, corresponding to a linear scale of 1.6 x 10(11) cm, about the diameter of the Sun, for a distance of 700 pc, separated by 0.54 km s(-1) in velocity and by 160 +/- 35 mu as in angle. This is the smallest angular structure ever observed in a Galactic maser. The brightness temperatures are greater than 2 x 10(14) K, and the line widths are 0.5 km s(-1). Most of the flux (about 87%) is contained in a halo of angular size of 400 +/- 150 mu as. This structure is associated with the compact HII region HW3diii. We have probably picked up the most prominent peaks in the angular size range of our interferometer. We discuss three dynamical models: (1) Keplerian motion around a central object, (2) two chance overlapping clouds, and (3) vortices caused by flow around an obstacle (i.e., von Karman vortex street) with a Strouhal number of about. 0.3.

A method for searching for new periodic radio sources is described. The method is based on the spectral analysis of data from daily monitoring of the sky on the Large Phased Antenna (LPA) of the Pushchino Radio Astronomy Observatory at 111 MHz in a 2.5-MHz band. The 96-beam directivity pattern of the LPA is used. The signal is received in six 0.42-MHz frequency channels with a sampling rate of 0.1 s. The duration of the processed survey is four months. The particulars of detecting periodic sources with the LPA are considered. In total, 16 such radio sources have been detected, for which equatorial and Galactic coordinates, periods, and dispersion measures are given.

УДК 004.048; 524.6 Предмет і мета роботи:  У процесі астрономічних спостережень накопичуються величезні обсяги даних. ВСА ФІАН (Велика скануюча антена Фізичного інституту Російської академії наук), яка використовується у дослідженні імпульсних явищ, щодня реєструє 87.5 Гб даних (32 Тб щороку). Метою роботи є розробка веб-сервісу для допомоги експертам у класифікації нових астрономічних спостережень. Студія машинного навчання Azure Machine Learning Studio, що підтримує алгоритм глибокої нейронної мережі, використовується як інструмент для розробки веб-сервісу. Методи і методологія: Експертами класифіковано 83096 індивідуальних спостережень (на відрізку дослідження липень 2012 – жовтень 2013). Понад 89 % вибірки відповідають пульсарам, мерехтливим джерелам і швидким радіотранзієнтам, а решта класів спостережень відносяться до апаратурних збоїв, перешкод, прольоту супутника Землі, літака. Всього виділено 15 класів спостережень. Результати:  Наявність подібної вибірки, поділеної на класи, дозволяє скористатися алгоритмами машинного навчання, за допомогою яких уможливиться розробка автоматизованого сервісу для короткострокового довгострокового моніторингу різних класів радіоджерел (у тому числі радіотранзієнтів різної природи), моніторингу іоносфери Землі, міжпланетної та міжзоряної плазми, пошуку й моніторингу різних класів радіоджерел. Моніторингом у даному разі розуміємо автоматичну фільтрацію і розпізнавання раніше некласифікованих імпульсних явищ. Наразі для автоматичної фільтрації використовуються методи статистичного аналізу. В роботі розглядається альтернативний метод з використанням алгоритму машинного навчання – нейронної мережі, яка обробляє подані на вхід первинні дані і, після обробки прихованим шаром, за допомогою вихідного шару визначає клас імпульсного явища. Висновок:  Створення моделі нейронної мережі, що навчена на вибірці та виконує класифікацію раніше некласифікованих імпульсних явищ, виконується за допомогою хмарного сервісу Microsoft Azure Machine Learning Studio. Веб-сервіс, створений на основі моделі, дозволяє класифікувати як поодинокі імпульсні явища в режимі реального часу (запит-відповідь), так і вибірку даних за певний період (пакетна обробка). Ключові слова: великі дані, глибокі нейронні мережі, класифікація імпульсних явищ Стаття надійшла до редакції 20.10.2017 Radio phys. radio astron. 2017, 22(4): 270-275 СПИСОК ЛІТЕРАТУРИ 1. Samodurov V. A., Dumsky D. V., Isaev E. A., Rodin A. E., Kazancev A. N., Fedorova V. A., and Belyatskij Yu. A. The daily 110 MHz radio wave sky survey: statistical analysis of impulse phenomena from observation in 2012-2013 // Odessa Astronomical Publications. – 2016. – Vol. 29. – P. 167–170. DOI: 10.18524/1810-4215.2016.29.85206 2. Taylor G. B., Ellingson S. W., Kassim N. E., Craig J., Dowell J., Wolfe C. N., Hartman J., Bernardi G., Clarke T., Cohen A., Dalal N. P., Erickson W.C., Hicks B., Greenhill L. J., Jacoby1 B., Lane W., Lazio J., Mitchell D., Navarro R., Ord S. M., Pihlstrom Y., Polisensky E., Ray P. S., Rickard L. J., Schinzel F. K., Schmitt1 H., Sigman E., Soriano M., Stewart K. P., Stovall K., Tremblay S., Wang D., Weiler K. W., White S., and Wood D. L. First Light for the First Station of the Long Wavelength Array // J. Astron. Instrum. – 2012. – Vol. 1, No. 1. – id. 1250004. DOI: 10.1142/S2251171712500043 3. Roman V. Ş. and Buiu C. Automatic Analysis of Radio Meteor Events Using Neural Networks // Earth Moon Planets. – 2015. – Vol. 116, Is. 2. – P. 101–113. DOI: 10.1007/s11038-015-9473-y

The Pushchino Observatory of ASC LPI have been developing in some last years database of some astronomical catalogs (Radio Astronomy Data Center - RADC, look on http://astro.prao.ru/db/ and http://observations.prao.ru/). In the database have the most commonly used by radio astronomers data: survey catalogs of radio sources at different radio frequencies (as well as in other spectral bands), catalogs of the major sky objects studied in astronomy etc.

Further analysis of data previously obtained during the monitoring observations of 49 as-trophysical water (22 GHz) masers shows that in some cases the intensity of an individual component of the maser spectrum changes periodically, on time-scales of tens of minutes. It is argued that this variation cannot be the effect of instrumental errors, weather conditions or interstellar medium instabilities, because only a single feature of the maser spectrum fluctuates but not the whole spectrum. The suggested interpretation of this effect is based on the opticmetrical parametric resonance produced by gravitational radiation emitted by short-period binary stars, with the examples of such binaries sufficing the conditions given.