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Статистика обнаружений импульсных сигналов в площадке со склонениями от +42° до +52° на частоте 111 МГц
Астрономический журнал. 2022. Т. 99. № 4. С. 334–341.
A search for impulse signals was carried out in a new site included in the monitoring program for the search for pulsars and transients. Processing of several months of 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; 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/cm3, 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 explicit pulsar pulses revealed 13 pulses belonging to four rotating radio transients (RRAT). Their dispersion measures are in the range 17 – 51 pc/cm3. 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 of 2–4 mJy at a frequency of 111 MHz.
Aleksei Samarin, Nazarenko A., Nazarenko D. et al., Machine Learning and Knowledge Extraction 2026 Vol. 8 No. 10 Article 330
Automated microscopic image analysis is essential for quantitative microbiology, yet manual acquisition and generic recognition models struggle with morphological variability and scene artifacts. We address both ends of this pipeline. First, we present a low-cost, open-source acquisition system, based on an Arduino UNO R3 microcontroller and NEMA 17 stepper motors, that automates focusing, magnification, and ...
Added: October 14, 2026
Parkhomenko V., Kulikova S., Buzmakov A. V., Lobachevskii Journal of Mathematics 2026 Vol. 47 No. 6 P. 2979–2992
The stability of formal concepts and its generalization as robustness are considered in the paper. We use an approximation of stability in the form of Δ-measure for fast calculations. A computationally efficient method for calculating robustness based on subcontexts is presented. We also present a new method to analytically evaluate the number of preimages for ...
Added: October 14, 2026
Kuznetsov A. P., Sedova Y. V., Sataev I. R. et al., Mathematics and Computers in Simulation 2027 Vol. 2 P. 574–592
Universal bifurcation structures on the parameter plane of nonlinear systems, known as shrimps, are discussed. An overview of numerous examples from various fields of science is given. Shrimps are typical for both maps of different dimensions and flows. The varieties of shrimp are discussed and relevant examples are given. The similarity property on the parameter ...
Added: October 14, 2026
Dmitriev A., Kornilov V., Batienkov R., Lecture Notes in Civil Engineering 2026 Vol. 886 P. 249–255
Numerous studies have provided compelling evidence that the probability distribution of avalanche sizes follows a power law, and that 1/f noise is present in the stochastic dynamics of landslides. We present a theoretical explanation of these phenomena within the framework of self-organized criticality theory, proposing a discrete-time model in the form of a sandpile cellular ...
Added: October 13, 2026
Dmitriev A., Shulman I., Lebedev A., Studies in Computational Intelligence 2026 Vol. 1265 P. 266–273
A discrete-time model is presented for the self-organization of the X/Twitter social network to the edge of a phase transition, characterized by avalanche-like propagation of information in the network. The model is based on the analogy between the critical dynamics of the X social network and sandpile cellular automata with Manna rule on the Chung-Lu ...
Added: October 13, 2026
Arutyunov K., Kharitonov I. A., Petrosyants K. O., JETP Letters 2026 Vol. 124 No. 6 P. 1–16
Superconducting properties of metallic micro- and nanowires can be entirely different from those of bulk superconductors. Of particular interest is the nonequilibrium current-induced state of a quasi-one-dimensional superconducting channel. The most interesting phenomenon here is the stepped I–V characteristic, explained by a process known as phase slip center activation. If the origin of such step-like ...
Added: October 13, 2026
Makarov D. M., Kalikin N., Fashchevsky K. A. et al., Electrochimica Acta 2026 Vol. 579 Article 150159
Machine learning (ML) has become a powerful tool for accelerating the development of carbon-based supercapacitors;
however, most published models assume that a single predictive framework can describe both conventional
porous carbons and hybrid carbon electrodes. Here, we test this assumption using a comprehensive
benchmark dataset and an extended literature-curated dataset enriched with synthesis- and electrolyte-related
descriptors. Three ML algorithms ...
Added: October 13, 2026
Gusein-Zade S., Campillo A., Delgado F., Mathematische Zeitschrift 2026 Vol. 314 No. 1 P. 1–22
For a subfield $\K$ of the field $\C$ of complex numbers, we consider curve and divisorial valuations on the algebra $\K[[x,y]]$ of formal power series in two variables with the coefficients in $\K$. We compute the semigroup Poincar\'e series and the classical Poincar\'e series of a (discrete, rank one) valuation on it. ...
Added: October 13, 2026
Махлуф М., Ozhegov R., Elezov M. et al., Фотоника 2026 Vol. 20 No. 6 P. 414–423
This paper compares the ranging precision of direct time-of-flight (dToF) and non-line-of-sight (NLOS) LiDAR architectures, both using a superconducting nanowire single-photon detector (SNSPD). Both systems operate at 1550 nm with a 50 ps pulsed laser and time-correlated single-photon counting (TCSPC). The dToF configuration achieved approximately 100 µm precision at 10 m, while the NLOS configuration achieved 500 µm precision for ...
Added: October 12, 2026
V. E. Shaposhnikov, Simonova T. V., Geomagnetism and Aeronomy 2024 Vol. 64 No. 7 P. 1044–1048
The electron cyclotron waves instability near the frequencies of electron cyclotron harmonics in an
electron–positron plasma is studied under conditions typical for the radio emission source with a quasi-harmonic
structure of the pulsar in the Crab Nebula. The increment of instability of longitudinal cyclotron waves
is calculated for an electron–positron plasma with a small admixture of energetic electrons ...
Added: March 11, 2025
Samodurov V., Тюльбашев С. А., Торопов М. О. et al., Астрономический журнал 2023 Т. 100 № 6 С. 517–523
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 ...
Added: November 13, 2023
Biryukov A., Beskin G., Monthly Notices of the Royal Astronomical Society 2023 Vol. 522 No. 4 P. 6258–6263
Numerical simulations predict that the spin-down rate of a single rotation-powered neutron star depends on the angle α between its spin and magnetic axes as $P\dot{P} \propto \mu ^2 (k_0 + k_1\sin ^2\alpha)$, where P is the star spin period, μ is its magnetic moment, while k0 ~ k1 ~ 1. Here, we describe a simple observational ...
Added: June 8, 2023
Novoselov E. M., Beskin V. S., Galishnikova A. K. et al., Monthly Notices of the Royal Astronomical Society 2020 Vol. 494 No. 3 P. 3899–3911
At present, there is no direct information about evolution of inclination angle χ between magnetic and rotational axes in radio pulsars. As to theoretical models of pulsar evolution, they predict both the alignment, I.e. evolution of inclination angle χ to 0°, and its counter-alignment, I.e. evolution to 90°. In this paper, we demonstrate that the ...
Added: October 31, 2022
Khokhryakova A. D., Biryukov A., Popov S. B., Astronomy Reports 2021 Vol. 65 No. 7 P. 615–630
A four-year sky survey with the use of the eROSITA telescope on board the Spektr-RG observatory with focusing optics will provide the best coverage in the soft (0.5-2 keV) and standard (2-10 keV) X-ray ranges, both in terms of sensitivity and angular resolution. We have investigated the possibility of detecting various types of single neutron ...
Added: October 31, 2022
Igoshev A., Popov S., Astronomische Nachrichten 2021 Vol. 342 No. 1-2 P. 216–221
The role of magnetic field decay in normal radio pulsars is still debated. In this paper, we present results which demonstrate that an episode of magnetic field decay in hot young neutron stars can explain anomalous values of braking indices recently measured for more than a dozen of sources. It is enough to have few ...
Added: March 24, 2021
Даниленко А. А., Карпова А. В., Ofengeim D. et al., Monthly Notices of the Royal Astronomical Society 2020 Vol. 493 No. 2 P. 1874–1887
We report results of XMM-Newton observations of a γ-ray pulsar J0633+0632 and its wind nebula. We reveal, for the first time, pulsations of the pulsar X-ray emission with a single sinusoidal pulse profile and a pulsed fraction of 23 ± 6 per cent in the 0.3-2 keV band. We confirm previous Chandra findings that the ...
Added: November 11, 2020
Igoshev A., Popov S., Monthly Notices of the Royal Astronomical Society 2020 Vol. 499 No. 2 P. 2826–2835
Recently, Parthsarathy et al. analysed long-term timing observations of 85 young radio pulsars. They found that 15 objects have absolute values of braking indices ranging ∼10–3000, far from the classical value n = 3. They also noted a mild correlation between measured value of n and characteristic age of a radio pulsar. In this article, we systematically ...
Added: October 23, 2020
Zheleznyakov V. V., V. E. Shaposhnikov, Monthly Notices of the Royal Astronomical Society 2020 Vol. 495 No. 4 P. 3715–3721
We study the origin of quasi-harmonic emission bands with fine structure observed in the
dynamic radiation spectra of high-frequency interpulses. The possible explanation of observed
structure is based on the effect of double plasma resonance (DPR) at electron cyclotron
harmonics realized in the magnetosphere of pulsar in a local radio emission source filled
with non-relativistic plasma. The model of ...
Added: September 10, 2020
Bespalov P. A., Olga N. Savina, Monthly Notices of the Royal Astronomical Society 2020 Vol. 498 P. 2864–2870
A model for the source of microwave main giant pulses (GPs) from the Crab pulsar is proposed and partly investigated. Pulse excitation takes place in a relativistic pair plasma with a strong magnetic field through the beam pulse amplifier (BPA) mechanism, in which short noise pulses of a certain type are amplified by energetic electrons ...
Added: August 18, 2020
Lutovinov A., Monthly Notices of the Royal Astronomical Society: Letters 2018 Vol. 479 No. 1 P. L134–L138
We report on the monitoring of the final stage of the outburst from the first Galactic ultraluminous X-ray pulsar Swift J0243.6+6124, which reached ˜40 Eddington luminosities. The main aim of the monitoring program with the Swift/XRT telescope was to measure the magnetic field of the neutron star using the luminosity of transition to the `propeller' ...
Added: November 1, 2018
Wijnands R., Tsygankov S., Degenaar N. et al., Monthly Notices of the Royal Astronomical Society 2017 Vol. 470 No. 1 P. 126–141
Observations of accreting neutron stars (NSs) with strong magnetic fields can be used not only for studying the accretion flow interaction with the NS magnetospheres, but also for understanding the physical processes inside NSs and for estimating their fundamental parameters. Of particular interest are (I) the interaction of a rotating NS (magnetosphere) with the infalling ...
Added: January 16, 2018
Lutovinov A., Monthly Notices of the Royal Astronomical Society 2016 Vol. 457 No. 1 P. 258–266
We report the results of a spectral and timing analysis of the poorly studied transient X-ray pulsar 2S 1553-542 using data collected with the NuSTAR and Chandra observatories and the Fermi/GBM instrument during an outburst in 2015. The properties of the source at high energies (>30 keV) are studied for the first time and the ...
Added: January 16, 2018
Samodurov V., Pozanenko A. S., Rodin A. E. et al., , in: Data Analytics and Management in Data Intensive Domains. XVIII International Conference, DAMDID/RCDL 2016, Ershovo, Moscow, Russia, October 11 -14, 2016, Revised Selected Papers.: Cham: Springer, 2017. P. 130–141.
One of the most sensitive radio telescopes at the frequency of 110 MHz is a Big Scanning Antenna (BSA) in Pushchino Radio Astronomy Observatory of Lebedev Physical Institute (PRAO LPI, Moscow region, Russia). Since 2012 in the BSA the continuous survey observation was started in multibeam mode in the frequency band of 109–112 MHz. Now ...
Added: May 21, 2017
Родин А. Е., Орешко В. В., Samodurov V., Астрономический журнал 2017 Т. 94 № 1 С. 35–43
Описан метод поиска новых периодических источников радиоизлучения, основанный на спектральном анализе, по данным ежедневного мониторинга неба на Большой синфазной антенне (БСА) Пущинской радиоастрономической обсерватории АКЦ ФИАН на частоте 111 МГц. Обсуждаются особенности обнаружения таких источников на БСА. Приводится список обнаруженных периодических источников (всего 16 пульсароподобных источников), их координаты, период и мера дисперсии. ...
Added: March 13, 2017