Ussuriysk Astrophysical Observatory
facilityUssuriysk, Russia
Research output, citation impact, and the most-cited recent papers from Ussuriysk Astrophysical Observatory (Russia). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Ussuriysk Astrophysical Observatory
We present optical and near-infrared (NIR) photometry for three gamma-ray burst supernovae (GRB-SNe): GRB 120729A, GRB 130215A/SN 2013ez, and GRB 130831A/SN 2013fu. For GRB 130215A/SN 2013ez, we also present optical spectroscopy at tt 0 = 16.1 d, which covers rest-frame 3000-6250 . Based on Fe 5169 and Si 6355, our spectrum indicates an unusually low expansion velocity of 4000-6350 km s -1 , the lowest ever measured for a GRB-SN. Additionally, we determined the brightness and shape of each accompanying SN relative to a template supernova (SN 1998bw), which were used to estimate the amount of nickel produced via nucleosynthesis during each explosion. We find that our derived nickel masses are typical of other GRB-SNe, and greater than those of SNe Ibc that are not associated with GRBs. For GRB 130831A/SN 2013fu, we used our well-sampled R-band light curve (LC) to estimate the amount of ejecta mass and the kinetic energy of the SN, finding that these too are similar to other GRB-SNe. For GRB 130215A, we took advantage of contemporaneous optical/NIR observations to construct an optical/NIR bolometric LC of the afterglow. We fit the bolometric LC with the millisecond magnetar model of Zhang & Mszros (2001, ApJ, 552, L35), which considers dipole radiation as a source of energy injection to the forward shock powering the optical/NIR afterglow. Using this model we derive an initial spin period of P = 12 ms and a magnetic field of B = 1.1 10 15 G, which are commensurate with those found for proposed magnetar central engines of other long-duration GRBs.
This work investigates the effect of transverse density structuring in coronal slab-like waveguides on the properties of fast waves. We generalized previous results obtained for the exponential and Epstein profiles to the case of an arbitrary transverse density distribution. The criteria are given to determine the possible (trapped or leaky) wave regime, depending on the type of density profile function. In particular, there are plasma slabs with transverse density structuring that support pure trapped fast waves for all wavelengths. Their phase speed is nearly equal to the external Alfvén speed for the typical parameters of coronal loops. Our findings are obtained on the basis of Kneser's oscillation theorem. To confirm the results, we analytically solved the wave equation evaluated at the cutoff point and the original wave equation for particular cases of transverse density distribution. We also used the WKB method and obtained approximate solutions of the wave equation at the cutoff point for an arbitrary transverse density profile. The analytic results were supplemented by numerical solutions of the obtained dispersion relations. The observed high-quality quasi-periodic pulsations of flaring loops are interpreted in terms of the trapped fundamental fast-sausage mode in a slab-like coronal waveguide.
Trends in adaptation to new habitats of orphaned bear cubs in the period of rearing and after release into the wild have been revealed. The pattern of their distribution in a biotope is contingent on its exploration in search for food, with the intensity and scale of this process increasing as the animals grow. The results indicate that the methods of rearing used in the Ussuri Nature Reserve are effective and promising.
Abstract We investigate the prompt emission and the afterglow properties of short-duration gamma-ray burst (sGRB) 130603B and another eight sGRB events during 2012–2015, observed by several multiwavelength facilities including the Gran Canarias Telescope 10.4 m telescope. Prompt emission high energy data of the events were obtained by INTEGRAL-SPI-ACS, Swift-BAT, and Fermi-GBM satellites. The prompt emission data by INTEGRAL in the energy range of 0.1–10 MeV for sGRB 130603B, sGRB 140606A, sGRB 140930B, sGRB 141212A, and sGRB 151228A do not show any signature of the extended emission or precursor activity and their spectral and temporal properties are similar to those seen in case of other short bursts. For sGRB 130603B, our new afterglow photometric data constrain the pre-jet-break temporal decay due to denser temporal coverage. For sGRB 130603B, the afterglow light curve, containing both our new and previously published photometric data is broadly consistent with the ISM afterglow model. Modeling of the host galaxies of sGRB 130603B and sGRB 141212A using the LePHARE software supports a scenario in which the environment of the burst is undergoing moderate star formation activity. From the inclusion of our late-time data for eight other sGRBs we are able to: place tight constraints on the non-detection of the afterglow, host galaxy, or any underlying ‘kilonova’ emission. Our late-time afterglow observations of the sGRB 170817A/GW170817 are also discussed and compared with the sub-set of sGRBs.
Aims. The effect of the transition layer (shell) in nonuniform coronal loops with a continuous radial density profile on the properties of fast-sausage modes are studied analytically and numerically.
We monitor the inner coma of comet 41P/Tuttle-Giacobini-Kres\'{a}k searching for variations of its colour. Fast changes in colour of the comet 41P/Tuttle-Giacobini-Kres\'{a}k provide important clues for better understanding of the microphysical properties of its dust. Using the 61-cm and 70-cm telescopes we measured the apparent magnitude of the comet with the V and R Johnson-Cousins filters from January 29 until April 25 of 2017. The inner coma ({\sim} 2000 km) reveals fast and significant variations of colour. The most significant change was found between March 3 and 4 of 2017, when it changed from blue with a colour slope S {\approx}(-10.15 {\pm} 3.43){\%} per 0.1 {\mu}m to red with S {\approx} (16.48 {\pm} 4.27){\%} per 0.1 {\mu}m. This finding appears in good accordance with what was previously reported by Ivanova et al. (2017) for long-period comet C/2013 UQ4 (Catalina), suggesting that fast and significant variations of colour of dust could be a common feature of short- and long-period comets. We model observations of comet 41P/Tuttle-Giacobini-Kres\'{a}k using the agglomerated debris particles and conclude that its inner coma consists of a mixture of at least two types of particles made of Mg-rich silicates and organics or Mg-Fe silicates.
A noninvasive evaluation method of hypothalamo-pituitary-adrenals axis (HPA) activity in the Siberian tiger was verified. Comparison of the activity level of HPA in Siberian tigers in the wild and in captivity, and their alterations over the year was carried out. Significant seasonal deviations between activity levels of HPA in tigers in captivity were not found. In the wild, this level was significantly higher, reaching the maximum from November to January, which can be related with an unfavorable influence on tigers in low temperatures and deep snow cover.
<i>Context. <i/>We present observations of the GRB 080319B afterglow at optical, mm, and radio frequencies between a few hours and 67 days after the burst.<i>Aims. <i/>We attempt to understand the nature of this extraordinarily bright explosion based on the observed properties and its comparison with afterglow models.<i>Methods. <i/>Our observations and other published multiwavelength data were used to reconstruct the light curves and spectral energy distributions of the burst afterglow.<i>Results. <i/>Our results indicate that the observed features of the afterglow agrees equally well with the inter stellar matter and the stellar wind density profiles of the circumburst medium. In the case of both density profiles, the maximum synchrotron frequency is below optical value and the cooling break frequency is below X-rays, ~10<sup>4<sup/> s after the burst. The derived value of the Lorentz factor at the time of naked-eye brightness is also ~300 for a corresponding blast-wave size of ~10<sup>18<sup/> cm.<i>Conclusions. <i/>The numerical fit to the multiwavelength afterglow data constraints the values of physical parameters and the emission mechanism of the burst.
We investigate fast sausage waves in a monolithic coronal magnetic tube, modeled as a local density inhomogeneity with a continuous radial profile. This work is a natural extension of our previous results, obtained for a slab loop model for the case of cylindrical geometry. Using Kneser's oscillating theorem, we provided the criteria for the existence of trapped and leaky wave regimes as a function of the profile features. For a number of density profiles there are only trapped modes for the entire range of longitudinal wave numbers. The phase speed of these modes tends toward the external Alfvén speed in the long wavelength limit. The generalized results were supported by the analytic solution of the wave equation for the specific density profiles. The approximate Wentzel–Kramers–Brillouin solutions allowed us to obtain the desired dispersion relations and to study their properties as a function of the profile parameters. The multicomponent quasi-periodic pulsations in flaring loops, observed on 2001 May 2 and 2002 July 3, are interpreted in terms of the transversely fundamental trapped fast sausage mode with several longitudinal harmonics in a smooth coronal waveguide.
The propagation of kink waves in the thin gravity stratified flux tubes with a generalized magnetic field distribution model is considered in cylindrical geometry. The new kink wave equations for both wave variables are obtained. It is shown that the inclusion of the radial component of an unperturbed tube magnetic field sufficiently transforms the conditions for the propagation of transverse waves. It is demonstrated that, for the models of isothermal and polytropic atmosphere in the tube and its environment, the propagation of kink waves along thin magnetic flux tubes is cutoff-free.
Based on multiyear observations in Tomsk (since 1995, in the wavelength range 0.37–4 μm) and other regions of the Asian part of Russia (2003–2008), we determined the specific features of the annual behavior of the characteristics of the spectral aerosol optical depth (AOD) of the atmosphere. It is shown that AOD peaks are observed in April (0.19 in the region of 0.5 μm) and July, a local minimum in June (less than 0.16), and minimum values in the fall (0.12). The seasonal variations of the Angström selectivity exponent are characterized by elevated values in the warm period (maximum in July) and low values in winter. The closeness of the seasonal variations of aerosol turbidity in three Siberian regions is noted, and the Siberia mean annual behavior of atmospheric AOD characteristics is suggested. The average values of the aerosol optical and microphysical characteristics of the atmospheric depth for characteristic periods of intraannual AOD variations are presented.
The possibility of application of satellite collars to the study of home range and activity of Amur tigers has been analyzed. The possibility of obtaining information about the size and structure of a home range, discerning the home range core areas, seasonal changes in the use of space by tigers, and collecting detailed data on animals’ activity and characteristics of the use of different elements of landscape and terrain has been demonstrated. In contrast to VHF transmitters, satellite collars allow tigers to be tracked even in the cases of very long travels.
Data on the distribution of Callipogon relictus Semenov, 1899 over the Russian Far East were generalized. The distribution map for C. relictus is based upon long-term observations and collection materials by the leading institutions. The chronology was studied within the Russian geographic range of the species.
Zonstein, Sergei, Marusik, Yuri, Omelko, Mikhail (2015): A survey of spider taxa new to Israel (Arachnida: Araneae). Zoology in the Middle East 61 (4): 372-385, DOI: 10.1080/09397140.2015.1095525
Context. The near-Earth asteroid (3200) Phaethon occasionally reveals a comet-like activity. It is a parent body to the Geminid meteor shower and considered as a target for the space mission called Demonstration and Experiment of Space Technology for Interplanetary Voyage Phaethon Flyby Dust Science, DESTINY + . Aims. We aim to characterize Phaethon through measurements of the degree of linear polarization P measured on Phaethon at large phase angles on its closest approach to Earth on December 17, 2017. These observations allow a more accurate estimation of the maximum value of the degree of linear polarization P max of Phaethon, and therefore, of studying the Umov effect. Methods. We performed polarimetric measurements of Phaethon at large phase angles α and thus constrained its P max . We also estimated the geometric albedo a based on the data available in the literature. The obtained P max and A were analysed with the Umov effect previously derived for the Moon that establishes an inverse linear correlation between log( P max ) and log( A ) in the lunar regolith. Results. Our polarimetric observations of Phaethon in the visible reveal the degree of linear polarization P ≈ (17.23 ± 2.00)% at α ≈ 57.9° and P ≈ (31.86 ± 2.00)% at α ≈ 73.2°, which demonstrates no significant wavelength dependence within the error bars of our measurements (± 2%). These data, when combined with what has previously been reported in the literature, suggests at least three types of polarimetric response on Phaethon. For two of them, we infer the maximum linear polarization to be P max ≈ 57.9%, occurring at α max = 131° and P max ≈ 44.5% occurring at α max = 127°. We estimate the geometric albedo (adjusted to α = 3°) to be A R = 0.075 ± 0.007 in the R filter, which appears to be consistent with dark F-type asteroids, as which Phaethon was first classified. We examine the Umov diagrams previously inferred for lunar regolith and find that they are hardly applicable to Phaethon and therefore not to other asteroids either.
Low-temperature plasma ejected in solar eruptions can screen active regions as well as quiet solar areas. Absorption phenomena can be observed in microwaves as “negative bursts” and in various spectral domains. We analyze two very different recent events with such phenomena, and present an updated systematic view of solar events associated with negative bursts. Related filament eruptions can be normal, without essential changes of shape and magnetic configuration, and “anomalous.” The latter are characterized by disintegration of an eruptive filament and dispersal of its remnants as a cloud over a large part of the solar disk. Such phenomena can be observed as giant depressions in the He II 304 Å line. One of possible scenarios for an anomalous eruption is proposed in terms of reconnection of the filament's internal magnetic fields with an external large-scale coronal surrounding.
We investigated relations among solar activity, climate and cosmogenic radiocarbon in a time series of various astrophysical, geophysical, archaeological and historical data. We studied records of tree-ring thickness, aurora borealis , the catalog of visible sunspots, sedimentary deposits from lakes and oceans, global glacial advance and retreat chronology, polar ice cores and human migrations. In these data, we searched for evidence of medium- and long-term solar cycles. Application of different spectral techniques to the atmospheric 14 C concentration time series indicates the existence of spectral lines at a few dominant periodicities ranging from 11 yr to ca. 2 ka. Different laboratories have confirmed the presence of the ca. 210-and 2000-yr spectral features in long 14 C series in tree rings. The ca. 210-yr 14 C cycle is probably caused by heliomagnetic modulation of the cosmic-ray flux. The extrema of both the ca. 210-yr 14 C period and solar activity correlate with the cold and warm epochs of global climate, at least for the past millennium, and this correlation has the correct sign. The periods of low solar activity are well correlated with the Little Ice Ages. The cause of the ca. 2 ka 14 C period is, as yet, uncertain, but evidence from the analyses of various natural records shows that it could have a solar origin. In this study, we obtained powerful manifestations of solar activity and climate warming epochs at ca. 1500, 3800, 6100, 8200, 10,500 and 12,600 bp. A similar feature occurs in epochs of minimum amplitude in the 14 C content in tree rings. Thus, solar activity may affect both the 14 C content in the Earth's atmosphere and climate.
Data of multiyear sun photometer measurements in the Asian part of Russia are used to analyze the issues regarding the modeling of annual and spectral behaviors of the atmospheric aerosol optical depth (AOD) based on separation of the contributions of fine and coarse aerosols. The specific features of the spatial distribution and seasonal variations in AOD characteristics in different regions are discussed; and a three-parameter model of annual behavior of spectral AOD in the range 0.34–4 μm for Western Siberia (Tomsk) is suggested.
The developmental biology of the relict longhorn beetle Callipogon relictus Semenov, 1899 was studied from egg to adult in the laboratory for the first time. The molting dynamics and morphometric characteristics of all the larval instars were determined. The location of larvae within the tree trunk was investigated by nondestructive modern methods. The reproductive behavior and the process of oviposition are described. Individual development of the species under laboratory conditions, at constant temperature and humidity, took 44 months, suggesting that in the nature it extends over at least four years.
We present an approach to extracting the regular component of diurnal behavior of the aerosol optical depth and columnar water vapor of the atmosphere. The daily average dynamics of these characteristics in Tomsk is compared with that in the suburban background region, as well as in a few other regions: Tomsk, Yekaterinburg, Irkutsk, Yakutsk, and Ussuriisk. We identified common features in the dynamics for the regions of Tomsk, Yekaterinburg, and Irkutsk. Some specific features, caused by the effect of local factors, are revealed for Yakutsk and Ussuriisk. We present parameters of approximation of the daily average behavior of the atmospheric AOD for Yekaterinburg, Tomsk, and Irkutsk.