This paper considers latest highlights in simultaneous and follow-up optical observations of high energy astrophysical phenomena by MASTER Global Robotic Net. Such extreme Universe sources includes gamma-ray bursts, gravitational wave events, detected by LIGO/Virgo, fast radio bursts, high energy neutrino sources and others. Some of the neutrinos detected by ground-based facilities owe their births to supermassive black holes – blazars, which are in a special anxious state with high statistical reliability. We discovered the effect of a rapid decrease in the brightness of the blazar PKS 0735+17 at the time of the multiple detection of the high-energy neutrino event IceCube-211208A. This decrease in brightness within several hours was detected with a high confidence (SNR 10) in comparison with a multi-day brightening state of the blazar, which was accompanied not only by a maximum increase in the average brightness, but also by an increase in the amplitude of its brightness fluctuations. Additionally, we analyzed all cases of successful observation of blazars around neutrino events and obtained statistically reliable indications of the relationship between neutrino events and optical activity of blazars in the doubled error box at the 4.2 σ level.
The paper presents an augmented reality display based on the free-space combiner, consisting of two holographic mirrors: flat and spherical. A feature of such a system is a high-reflection coefficient of mirrors up to 90% for one wavelength and a high transmittance to the lumen up to 67% throughout the rest of the visible spectrum, unlike similar solutions implementing principles of polarization or dichroic beam splitting. The recording scheme and calculation of a separate flat holographic mirror and spherical holographic mirror are described. The proposed augmented reality display can provide multifocality, i.e., reproduction of virtual images at several distances, which demonstrates a certain perspective of this implementation in terms of compensation for the vergence accommodation conflict.
We present the algorithm of exoplanets transit search in MASTER global robotic telescope network database, that has been created with the involvement and use of artificial intelligence methods. MASTER’s 2003–2023 years archive images are stored at data storage and analysis center in Lomonosov supercomputer. For exoplanets transit search we used the images of SWIFT gamma-ray bursts alerts (GRB), received by MASTER telescopes during several hours at target nights. The algorithm includes cross-correlation of GRB error-boxes coordinates and TESS exoplanetary transits candidates inside 4 square degrees of each field. Our analyses is based on wide-field images obtained on MASTER-Amur, -Tunka, -Kislovodsk, -Tavrida, MASTER-IAC, MASTER-OAGH, MASTER-OAFA and MASTER-SAAO robotic telescopes. We used data storage and analysis center in Lomonosov supercomputer with MASTER images archive, calculated light curves for target stars and approximate them to find eclipse by exoplanets. The centralized storage of this data allows us to simplify and significantly speed up access to the huge archive of images formed during the entire operation of the robotic network for automatic processing and facilitate the manual search for the necessary information by the researcher. From this storage we compared the program with unique long homogeneous series of Swift GRBs alert and inspection observations, which we analyzed. The main result is reduction of unique light curves of exoplanetary transits of TIC 127115861.01 TESS candidate, obtained by MASTER long before the TESS space observatory.
The paper presents the method for detecting exoplanets in the image archive obtained by telescopes of the MASTER Global Network since 2002. The unique archive represents homogeneous photometric data obtained over 20 years for the northern (MASTER-Amur, MASTER-Tunka, MASTER-Kislovodsk, M-ASTER-Tavrida, MASTER-IAC, MASTER-OAGH) and 11 years for the southern sky (MASTER-OAFA, MASTER-SAAO). Algorithm of gamma-ray burst error box observation on the MASTER wide-field telescopes make it possible to detect transit phenomena and find exoplanets in archival data. The article presents the results of a photometric analysis of the TESS exoplanet candidate TOI–3570.01.
Optically Variable Devices (OVDs) are widely used as security features in anti-counterfeiting efforts. OVDs enable the display of color dynamic effects that are easily interpreted by the user. However, obtaining these elements over large areas poses certain challenges in terms of efficiency. The paper presents a modified approach for manufacturing plasmonic type OVDs through dot-matrix technology, which is a standard origination step of security holograms. By adjusting the spatial filters in the optical scheme, it is possible to double the resolution of the recorded quasi-sinusoidal diffraction gratings. The experiments confirm the creation of diffraction gratings with frequencies from 1600 to 3500 lines per mm, which facilitates the production of plasmonic zero-order spectral filters. The paper shows how the transmission characteristics of the studied elements are affected by the geometric parameters of the diffraction grating, silver layer thickness, angle of incidence, and polarization of light. The results have shown that using the proposed method it is possible to obtain 1D or 2D structural color OVD-image on a large area - several square centimeters and more. High speed recording of such elements is provided: the exposure time was from 120 to 400 ms depending on the grating resolution for a 0.05 mm2 frame, the total printing time for the size of the 25×25 mm2 OVD was about 2.5 hours for a 1D element, and less than 3.5 hours for a 2D element. Thus, the proposed method and the OVD elements produced by it can be useful to designers of optical security elements as a simpler and faster alternative to electron-beam lithographic technologies.
We present the results of photometric and spectroscopic monitoring campaigns of the changing look AGN NGC~2617 carried out from 2016 until 2022 and covering the wavelength range from the X-ray to the near-IR. The facilities included the telescopes of the SAI MSU, MASTER Global Robotic Net, the 2.3-m WIRO telescope, Swift, and others. We found significant variability at all wavelengths and, specifically, in the intensities and profiles of the broad Balmer lines. We measured time delays of ~ 6 days (~ 8 days) in the responses of the H-beta (H-alpha) line to continuum variations. We found the X-ray variations to correlate well with the UV and optical (with a small time delay of a few days for longer wavelengths). The K-band lagged the B band by 14 +- 4 days during the last 3 seasons, which is significantly shorter than the delays reported previously by the 2016 and 2017--2019 campaigns. Near-IR variability arises from two different emission regions: the outer part of the accretion disc and a more distant dust component. The HK-band variability is governed primarily by dust. The Balmer decrement of the broad-line components is inversely correlated with the UV flux. The change of the object's type, from Sy1 to Sy1.8, was recorded over a period of ~ 8 years. We interpret these changes as a combination of two factors: changes in the accretion rate and dust recovery along the line of sight.
Anisotropic magnetoelectric (ME) effects are investigated in a planar multiferroic heterostructure consisting of a piezoelectric lead zirconate-titanate substrate and a grating of ferromagnetic Ni-strips electrodeposited on its surface. The heterostructure is placed in a tangential dc magnetic field H and excited by an alternating magnetic field h at the frequency of bending acoustic resonance. It is shown that the magnitudes of both the linear and nonlinear ME effects depend on the orientation of the h and H fields with respect to the axis of Ni-strips and the distance between the strips. Strong anisotropy of ME effects arises due to demagnetization in a single Ni-strip and dipole-dipole interaction between the adjacent strips. The calculation technique is proposed that qualitatively well describes the anisotropy of linear and nonlinear ME effects in the heterostructure. The anisotropic ME effect can be used to create magnetic field sensors sensitive to the field orientation.
We report on the earliest detection of the optical transient MASTER OT J123248.62-012924.5 coincident within the error box with the optical and X-ray transient AT2021lfa/ZTF21aayokph. In our images the brightness of the object rises monotonically with $$7\sigma$$ confidence. We interpret this transient as a gamma-ray burst (GRB) characterized by smooth optical self-similar (SOSS) emission, while the nondetection of gamma-ray emission at space observatories is interpreted in terms of the hypothesis of a ‘‘failed’’ GRB. Thus, this is the first detection of a nonmonotonic orphan burst.
In this research, studies were conducted on the possibility of providing thermal compensation of the information display device circuit based on a holographic waveguide when the wavelength of the radiation source ch as a result of changes in ambient temperature. A variant of implementing the waveguide structure in terms of the geometry of the diffraction gratings arrangement is proposed, its main parameters (grating period, thickness, refractive index) and the dependencies between them affecting the quality of the reproduced image are determined.
Subject of study. The capabilities of the technologies for marking products and security holograms based on the analysis of the spectral properties of molecular structures introduced to the holograms are considered in combination with the adoption of quantum dots and magnetic microparticles (MPs). The primary focus is on the issues of the analysis of the Raman spectra of molecules excited by plasmonic-resonant electromagnetic fields. Method. Modern technologies for hologram security are based on the use of various protective optical effects concealed from visual observation. These effects reveal themselves only under the relevant illumination of holograms when specialized optical equipment is employed. Unique methods for marking and identification of holograms using the magneto-optical, fluorescent, and spectral properties of the emission of MPs and molecular structures with sizes ranging from tens of nanometers to tens of micrometers, which are excited by localized electromagnetic fields, are considered. The plasmonic-resonant methods for the excitation of marking molecular labels introduced into the hologram structures are the most relevant, together with the arising spectra of surface-enhanced Raman scattering that are used for the identification and authenticity verification of the holograms. Main results. The use of plasmonic-resonant methods for concentrating electromagnetic fields for the excitation of marking molecular labels was demonstrated to be able to ensure the amplification of their Raman emission by several orders of magnitude, which results in the significant enhancement of recognizability and identification of security holograms. Practical significance. The technologies for hologram protection proposed in this work are based on the combination of different types of markings such as hidden holographic images, magneto-optical and fluorescent images of MPs, and Raman spectra of molecular structures that are enhanced by plasmonic-resonant methods. These technologies significantly increase the reliability, security, and authenticity of the marking and its identification. The results of this study will help in forming the basic technical requirements for design of portable devices for the identification of security hologram markings. (C) 2022 Optica Publishing Group
Considering the limited resources of fossil energy and the problems caused by the emission of greenhouse gases, it is necessary to pay more attention to renewable energies, because in this way, the goals of sustainable development can be achieved. The importance of renewable energies in sustainable development, reducing greenhouse gases and increasing energy security on the one hand, and the need for financial resources and large investments for renewable energy projects on the other hand, doubles the role and importance of financial development in the development of renewable energies. Considering the importance of this issue, the present study examines the impact of the development of modern facilities and renewable energy technology. In this study, dynamic interactions in the Sustainable-Energy-Energy Development Pattern of carbon dioxide are investigated using the Bayesian Vector Auto Regression (BVAR) method. One of the most important indicators for evaluating sustainable development is the modified pure arrangement (GS). For this purpose, this index was used as a sustainable development index. The results indicate that the effect of positive impulse on renewable and renewable energy consumption on sustainable development in Uganda is positive. In addition, the positive shock of renewable and renewable energy consumption increases the emissions of carbon dioxide pollutants to a different extent. In addition, the effect of the growth of sustainable development index on renewable energy consumption and renewal energy consumption is (CO2) negative. The research results show that based on the RMSE criterion, the former SSVS-Full function was used to investigate the impact of renewable energy consumption on sustainable development and the independent Normal-Wish art function was used. Therefore, in this research, the dynamic relationships between sustainable development, energy consumption (separately from renewable and non-renewable energy) and CO2 emissions are investigated.
In this paper, laser shock peening (LSP) treatment was performed on Zr35Ti30Cu10Ni5Be20 bulk metallic glass (BMG) and the effects of induced energy on the characteristics of glassy structure were evaluated. The high resolution atomic force microscopy (AFM) and nanoindentation tests were carried out to characterize the nanoscale heterogeneity and micromechanical properties in the depth of material. According to the results, the surface of material showed a high heterogeneous structure, which was the sign of structural rejuvenation. However, with the move into the depth of material, the nanoscale heterogeneity decreased and eventually a relaxed region with the minimum heterogeneity was found in the 1.5–2 mm depth of BMG sample. Passing the relaxed region, again the nanoscale heterogeneity similar to the as-cast sample was observed. The nanoindentation results also confirmed the AFM outcomes. It is suggested that the relaxed region at the neighbor of rejuvenated region is due to the satisfaction of elastic adaptability which is resulted by the nanoscale shear events and the induced stress.
— We present the results of early observations for 130 error-boxes of gamma-ray bursts performed with the Mobile Astronomical System of TElescope-Robots (MASTER) global network of robotic telescopes from Moscow State University in fully automatic mode (2011–2017). Among them, GRB 130907A, GRB 120811C, GRB 110801A, GRB 120404A, GRB 140129B, GRB140311B, and GRB 160227A are considered in details. Among these 130 gamma-ray bursts, in the first 60 s after the trigger with the Swift, Fermi, INTEGRAL, MAXI, Lomonosov, and Konus-Wind orbital observatories, the MASTER was pointed on 51 gamma-ray bursts, being the leader in terms of the first pointing. Full observation automation and MASTER own real-time image processing software allowed us to obtain unique data on early optical emission that accompanied 44 gamma-ray bursts (GRB 110801A, GRB120106A, GRB 120404A, GRB 120811C, GRB 120907A, GRB 121011A, GRB 130122A, GRB 130907A, GRB 131030A, GRB 131125A, GRB 140103A, GRB 140108A, GRB 140129B, GRB 140206A, GRB 140304A, GRB 140311B, GRB 140512A, GRB 140629A, GRB 140801A, GRB140907A, GRB 140930B, GRB141028A, GRB 141225A, GRB 150210A, GRB 150211A, GRB 150301B, GRB 150323C, GRB 150404A/Fermi trigger 449861706, GRB 150403A, GRB 150413A, GRB 150518A, GRB 150627A, GRB 151021A, GRB 151215A, GRB 160104A, GRB 160117B, GRB 160131A, GRB 160227A, GRB 160425A, GRB 160611A, GRB 160625B, GRB 160804A, GRB 160910A, GRB 161017A, GRB 161117A, GRB 161119A). We obtain light curves for 13 gamma-ray bursts among the above listed ones and compare the data in the optical (MASTER), X-ray (Swift-XRT), and hard X-ray (Swift-BAT) ranges.
Seven gamma-ray bursts – GRB 130907A, GRB 140311B, GRB 140129B, GRB 160227A, GRB 120404A, GRB 110801A, and GRB 120811C were observed by the MSU MASTER (Mobile Astronomical System of TElescope Robots) Global Network. Full automation of the observations provided for obtaining unique data on the properties of early optical radiation accompanying gamma-ray bursts. The data are compared in the optical (MASTER), X-ray (SWIFT X-ray Telescope, XRT) and gamma (SWIFT Burst Alert Telescope, BAT) ranges. Based on the data obtained, two groups are identified, and their radiation mechanisms are revealed. The effect of gamma-ray bursts on the biosphere of the Earth is determined, and the estimates and the scale of such an effect are considered.
We investigate the long GRB140629A through multiwavelength observations, which cover optical, infrared and X-rays between 40s and 3yr after the burst, to derive the properties of the dominant jet and its host galaxy. Polarisation observations by the MASTER telescope indicate that this burst is weakly polarised. The optical spectrum contains absorption features, from which we confirm the redshift of the GRB as originating at z=2.276. We performed spectral fitting of the X-rays to optical afterglow data and find there is no strong spectral evolution. We determine the hydrogen column density to be 7.2x10^21cm^-2 along the line of sight. The afterglow in this burst can be explained by a blast wave jet with a long-lasting central engine expanding into a uniform medium in the slow cooling regime. At the end of energy injection, a normal decay phase is observed in both the optical and X-ray bands. An achromatic jet break is also found in the afterglow light curves 0.4d after trigger. We fit the multiwavelength data simultaneously with a model based on a numerical simulation and find that the observations can be explained by a narrow uniform jet in a dense environment with an opening angle of 6.7deg viewed 3.8deg off-axis, which released a total energy of 1.4x10^54erg. Using the redshift and opening angle, we find GRB 140629A follows both the Ghirlanda and Amati relations. From the peak time of the light curve, identified as the onset of the forward shock (181s after trigger), the initial Lorentz factor is constrained in the range 82-118. Fitting the host galaxy photometry, we find the host to be a low mass, star-forming galaxy with a star formation rate of logSFR=1.1^+0.9_-0.4Myr^-1. We obtain a value of the neutral hydrogen density by fitting the optical spectrum, logN(HI)=21.0+-0.3, classifying this host as a damped Lyman-alpha. High ionisation lines are also detected in the spectrum.
Magneto-optical devices are actively used to identify and verify magnetic images. We propose magneto-optical plasmonic nanostructures as sensitive material for detecting magnetic images and magnetic information. We show the increase in magneto-optical responce by utilizing plasmonic principals compared with structures of pure magneto-optical material.
The results of white-light photometry for a uniquely long series of data (13.5 hours of observations, 1124 measurements) for the Near-Earth Asteroid (NEA) 2015 TB145 are presented. These data were obtained with the MASTER-Amur and MASTER-Tavrida wide-field robotic telescopes of the Mobile Astronomical System of Telescope-Robots (MASTER) global network of Lomonosov Moscow State University, located in the Crimea and in Blagoveshchensk. The object moved by more than 120° during the observations. The asteroid passed the point of closest approach to the Earth, i.e., observations were carried during both the asteroid's approach and recession. Thus, due to the geometry of the passage, this series of observations contains information about the asteroid viewed at different angles, and is very suitable for precisely determining the shape of the object. Mathematical modeling of the light curve and astrometric positions (with the Asteroids3D code) was carried out, and the probable shape of the asteroid (conical) and the rotation period of 5.9 hours were obtained, as well as the orientation of the rotation axis in ecliptic coordinates: longitude λ = 53°, latitude β = −20°. The derived period coincides with twice the period of 2.9 hours obtained by other observers published earlier, within the uncertainties.