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We present the spectral and timing study of V404 Cygni from all its available Chandra observations and which recently come up in public domain of Chandra data archive. The data reduction and analysis were done using CIAO 4.14 and HEASOFT 6.30.1. The spectral analysis was done using spectral fitting package XSPEC version 12.12.1, available in the Heasoft package. The spectra of the source is fitted in the energy range 0.3 -8.0 keV using two empirical spectral models - the absorbed power law and an absorbed disk-blackbody. The X-ray binary source V404 Cygni is found to be in the quiescent state having the X-ray luminosity in the range with few times 1032 erg s−1. The source is found to be in the hard state and is well explained by power-law model with a powerlaw photon index Γ ∼ 2 with nH in the range ∼ (0.7 -1.2) × 1022 cm−2. From timing analysis, Src-1 (V404 Cygni), in all the time bins- 0.5, 1 and 2 ks, the probability for the count rate to be constant is 0.17 ×10−33 in all the observations in the year 2021 and 2023 (ObsID 23421, ObsID 23422, ObsID 23423 & ObsID 28927). However, in the year 2017 observation it is found to be less variable. This clearly shows the presence of short-term variability in kilo-seconds time-scales with the currently available Chandra data. So, it is indicative that the binary source V404 Cygni is more likely to be variable source both in long-term (years) as well as short-term (kiloseconds) scales.

This report presents a comprehensive analysis of the spectral and temporal characteristics of a highly significant Ultraluminous X-ray Source (ULX) designated as CXOUJ122956.7+075728 (ULX-1) situated in the elliptical galaxy NGC 4472 within the Virgo cluster. ULX-1 exhibits a soft spectral state, featuring a cool accretion disk component with kTin ∼ 0.15 keV, accompanied by a power-law tail displaying a steep power-law photon index, Γ ∼ 2.8. The spectral findings strongly support an estimated black hole mass of approximately 3.30 × 103 M⊙ under an isotropic emission model, and around 1.47 × 103 M⊙ in an extreme beaming scenario. Temporally, ULX-1 displays significant variability on time scales of 0.5, 1, and 2 ks, suggesting the possibility of instabilities within the accretion disk contributing to this behavior. However, despite this temporal variability, the power spectra analysis of this soft ULX reveals no signatures of pulsations, distinguishing it from certain pulsating ULXs (PULXs) typically associated with neutron stars. This absence of pulsations in ULX-1 further underscores its unique spectral and temporal characteristics within the broader context of ULX phenomena.

The present work aims to study the previously unstudied Ultraluminous X-ray sources (ULXs) in the galaxy NGC 3585 at its various epochs of Chandra observation. We report here the detection of two new ULXs viz. CXOUJ111306.0-264825 (X-1) and CXOUJ111325.3-264732 (X-2) with their bolometric luminosity > 1039erg s−1 in its various Chandra observations. X-1 was found to be a spectrally hard ULX in both the epochs where it was detected. However in the ULX, X-2, a slight hardening of the spectra was observed within a period of 17 years. Assuming isotropic emission and explained by disk blackbody model, the spectrally softer epoch of X-2 with an inner disk temperature, kTin ∼ 0.79 keV and bolometric luminosity ∼ 2.51 × 1039erg s−1 implies for X-2 to be powered by a compact object, necessarily a black hole of mass, MBH ∼ 44.85+82.11−25.92M⊙ accreting at ∼ 0.42 times the Eddington limit. The Lightcurve of X-1 and X-2 binned at 500s, 1ks, 2ks and 4ks has shown no signature of short-term variability in both the ULXs in kilo-seconds time scales. Overall, both the detected ULXs seem to be almost static sources both in long-term (years) as well as short-term (kilo-seconds) time scales with the presently available Chandra Observations.

The formation of continental crust in the Mongolia-Transbaikalia region is researched to identify the mechanisms of interactions between the crust and the mantle in the development of the Neoarchean, Proterozoic and Paleozoic magmatic and sedimentary complexes in the study area. Using the results of his own studies conducted for many years and other published data on this vast region of Central Asia, the author have analysed compositions, ages and conditions for the formation of Karelian, Baikalian, Caledonian and Hercynian structure-formational complexes in a variety of geodynamic settings. Based on the geostructural, petrological, geochemical, geochronological and Sm-Nd isotope data, he determines the crustal and mantle sources of magmatism, conducts the identification and mapping of isotopic provinces, and reveals the role of island-arc oceanic, accretion-collision and intraplate magmatism in the formation of continental crust. Considering the formation of the bulk continental crust, three main stages are distinguished: (1) Neoarchean and Paleoproterozoic (Karelian) (almost 30% of the crust volume), (2) Meso-Neoproterozoic (Baikalian) (50%), and (3) Paleozoic (Caledonian and Hercynian) (over 20%). This sequence of the evolution stages shows the predominance of the ancient crustal material in igneous rocks sources at the early stage. During the subsequent stages, tectonic structures created earlier were repeatedly reworked, and mixed crustal-mantle and juvenile sources were widely involved in the formation of the bulk continental crust in the study area.

Research subject. This article is devoted to the formation features of the Ural-Timan-Paleo-Asian segment of Eurasia. Materials and methods. The research was based on the authors’ data and those obtained following a review of available publications on the geology of segmentation. The Timan region was investigated using the geological information obtained by V.G. Olovyanishnikov.Results. A geodynamic map of the Ural-Timan-Paleo-Asian segment with a scale of 1 : 2 500 000 was compiled, which allowed further research into the structure and formation of the north-western part of the Eurasian area. This part was found to be mostly composed of geodynamic associations of orogens, orogenic systems and orogenic belts of the Upper Proterozoic (Riphean) and Paleozoic time intervals, as well as by elements of the Mesozoic-Cenozoic neoplate. These processes were supplemented by the formation of tectonic systems of superimposed depressions and protoplate protrusions. The formation of orogens, orogenic systems and orogenic belts is associated with the development and subsequent transformation of paleooceanic basins under the conditions of accretion and collision. The terranes of the ancient continental crust also participated in the formation of the segment’s geodynamic elements, for which a typification scheme was proposed. The articles present new data on the formation conditions of the segment’s orogenic elements and the relationship of the orogeny with global reconstructions, including the problem of closing the surrounding oceanic space.

The Main Uralian fault (MUF) zone is a suture at the junction of the Urals and the East European platform (EEP). Its complex tectonic melange is still poorly studied. We obtained new data on compositions and ages of the Krutorechensky granites (KG) composing an intensely tectonized and boudinaged elongated body discovered in meta‐ terrigenous and meta‐volcanogenic rocks in the western part of the MUF zone. In chemical composition, these gra‐ nites are similar to the Vendian‐Cambrian collisional granitoids of the Isherim and Lyapin blocks. The LA‐ICP‐MS method was used to determine U‐Pb zircon ages for the KG samples. The zircons contain ancient xenogenic cores (1221–1034 Ma) and young rims (400±6 Ma). The Middle Riphean ages of zircons from the protolith suggest that the KG block (belonging to the Prisalatim zone and located west of the MUF zone) is a fragment of the EEP, because the complexes of the Ordovician‐Devonian Tagil paleo‐island arc (located further eastward) are mostly dated to the Ven‐ dian. The KG crystallization age (537±2 Ma) is practically the first (Vendian) early Cambrian dating for the granites sampled in the MUF zone. Considering this age and the petrogeochemical features, there are grounds to suggest that the Krutorechensky granites originated due to tectonic‐magmatic events (with possible pluming) that took place at the final stage of the Timan collision, similar to granites of the western slope of the Northern Urals (Moiva, Posmak and Velsov massifs). Subsequently, these granites were involved in the Paleozoic accretion‐collision processes that created the modern MUF zone (i.e. tectonic melange). Our study results are important for clarifying the structure of the Urals‐EEP junction zone and useful for geological mapping and metallogenic assessment of the region.

Our study was focused on the active tectonics of the southern slope of the Greater Caucasus within Azerbaijan. The study area is the zone of under-thrusting (pseudosubduction) interaction between Southern and Northern Caucasus continental microplates, which caused the tectonic stratification of the Alpine formations into various allochthonous and parauthochthonous thrust slices of southern vergency between the Middle Bajocian and Quaternary periods. These slices are grouped into the nappe complexes that form the modern structure of the trough in the study area. The large linearly stretched tectonic units (megazones) correspond to the axis of the Alpine marginal sea basin, the consolidated crust of which is subjected to destruction and thinning. The trough’s Alpine cover was compressed in the underthrust zone and pushed southwards. As a result, an accretionary prism formed allochthonously overlapping the northern side of the Southern Caucasus microplate by the system of gently dipping overthrusts. During the continental stage of Alpine tectogenesis (starting from the end of Miocene), intensive lateral compression process was caused by intrusion of the frontal wedge of the Arabian indenter into the buffer structures of the southern frame of Eurasia. This is evidenced by the GPS monitoring data on modern geodynamic activity, which demonstrates the Southern Caucasus block’s intensive (up to 29 mm/year) intrusion in the northern rhumbs as compared to the relative stability of the Northern Caucasus microplate (0–6 mm/year). This, in turn, is a reflection of the ongoing pseudosubduction regime (continental subduction or S-subduction) at the band of collision junction of these microplates. It is suggested that this process caused historically observed seismic activity in the study area, wherein the earthquakes occurred mainly in the southern slope’s accretionary prism area and the adjacent strip of the Southern Caucasus microplate. In this article, we analyze and correlate the whole range of seismic events that occurred in the study area until 2017 and the focal mechanisms of the recently recorded earthquakes (2012–2016). It is established that earthquake foci are confined either to the intersection nodes of variously trending ruptures with the faults of different directions or to the planes of deep tectonic ruptures and lateral displacements along the unstable contacts between the material complexes with different competence. The focal mechanisms of seismic events reveal various, mostly near-vertical, planes of normal and strike-slip faults. However, the earthquake foci are generally confined to the intersection nodes between the Caucasus and anti-Caucasus-striking rupture dislocations. The results of our studies are interesting in terms of their real-time application for drawing a regional summary of causes for both geodynamic and seismic activity of the Greater Caucasus system and the adjacent areas of Alpine-Himalayan fold belt.

General positions on plate-tectonic metallogeny are presented and the grounds for singling out the metallogenic factors of orogenic systems are given. Mobilistic paradigma corresponds to the genotype of orogens and belts which being formed at the expense of oceanic basin transformations. Their alternative character for the factors of fixistic constructions is stressed. The conclusion is made that as a theoretical basis for the analysis of orogen system metallogeny - that is the metallogeny of considering in the paper segment - are the metallogenic factors connected with processes of movement and dislocation of lithospheric plates, geodynamical regimes of riftogenic extension and spreading of plates, geodynamical environments of subduction, accretion and collision. A decisive role of the factor of movement and dislocation of lithospheric plates makes it possible to introduce for this type of metallogeny the denomination of plate-tectonic metallogeny . A comparative analysis of metallogeny of modern oceanic basins and of epioceanic orogens showed that metallogenetic factors of geodynamical environments characterize their ore specialization, while the accretions and collisions define the location of ore concentrations, determining, in the long run, combination in orogenic systems of pre-accretion, accretion and post-accretion metallogenic elements. On the given basis taking into account regional particularities the metallogeny analysis of Ural-Timan-Paleoasian segment of Eurasia has been made. Diagrams of metallogeny and the segment metallogenic zoning were suggested.

The South-Ural accretion-collision fold belt began to form at the final stage of the island-arc development of the Urals. This process correlates in time with the Famennian and Early Tournasian. During the Carboniferous, the subsequent inversion from the island-arc tectono-geodynamic regime to the accretion-collision and transformed shear-riftogenous ones resulted in a considerable increase in diversified magmatic products. We can observe an intricate spatial and temporal combination of magmatic complexes differing in primary sources and genesis of mantle, mantle-crust and essentially crust anatectic magmatic complexes. The existence of the intraplate-type mantle series is associated with the destruction of the subducting oceanic plate and the rise of hot astenospheric diaper plumes up to the basement of the newly-formed lithosphere. The intrusive gabbro-granite magmatism of that time corresponds to the highest chlorine content and the formation of large-scale magnetite skarn mineralization. Along with the intraplate-type magmatic associations and rock series with intermediate features, this geodynamic setting is also characterized by a considerable amount of mantle-crust granitoids of the gabbro-tonalite-granodiorite-granite (GTGG) type formed with multiple manifestations of supra-subduction and crust (lowermost) anatectic processes. For these stages in the formation of the Hercynian South-Ural orogen, we have established a number of tectono-magmatic stages characterizing the magmatism of such tectonic events that accompanied the attachment of the Magnitogorsk Palaeo Arc and the eastward heterogeneous accretion assemblage to the margin of the East European Plate. Another goal of this paper is to typify the Permian granitoid magmatism, where mantle-crust gabbro-montzodiorite-granite latitic (282-274 Ma) and crust-palingenous granitic (290-276 Ma) and leucogranites (275-260 Ma) series were synchronously formed.

There are complex of data about composition, age, isotopic parameters for granites from the Ufaley block, which is situated in the accretion zone on the boundary between the Urals and the East European platform. Granitoides mark the main stage of the geological structure evolution: from the intraplate rifting (episodes 1100-880, 570-533, 476-457 Ma) with full and partial rupture of the crust to the beginninf of orogenes (about 317 Ma) and collision (260-250 Ma). On the base of isotopic data we show that there is the substantial evolution of the source in time reflecting the increasing of part of sialic component in the source for granite formation. Maximal quantity of the granite impulses was fixed within the Ufaley block and it’s neighboring marginal structure - Bashkirian anticlinorium. This fact notes to involvement here the margin of East European platform to all episodes of tectonic-magmatic activity from the Riphean rifting to Paleozoic orogenesis which was maximal during the formation the own Uralian collision orogen.

There are complex of data about composition, age, isotopic parameters for granites from the Ufaley block, which is situated in the accretion zone on the boundary between the Urals and the East European platform. Granitoides mark the main stage of the geological structure evolution: from the intraplate rifting (episodes 1100-880, 570-533, 476-457 Ma) with full and partial rupture of the crust to the beginninf of orogenes (about 317 Ma) and collision (260-250 Ma). On the base of isotopic data we show that there is the substantial evolution of the source in time reflecting the increasing of part of sialic component in the source for granite formation. Maximal quantity of the granite impulses was fixed within the Ufaley block and it’s neighboring marginal structure - Bashkirian anticlinorium. This fact notes to involvement here the margin of East European platform to all episodes of tectonic-magmatic activity from the Riphean rifting to Paleozoic orogenesis which was maximal during the formation the own Uralian collision orogen.

The South-Ural accretion-collision fold belt began to form at the final stage of the island-arc development of the Urals. This process correlates in time with the Famennian and Early Tournasian. During the Carboniferous, the subsequent inversion from the island-arc tectono-geodynamic regime to the accretion-collision and transformed shear-riftogenous ones resulted in a considerable increase in diversified magmatic products. We can observe an intricate spatial and temporal combination of magmatic complexes differing in primary sources and genesis of mantle, mantle-crust and essentially crust anatectic magmatic complexes. The existence of the intraplate-type mantle series is associated with the destruction of the subducting oceanic plate and the rise of hot astenospheric diaper plumes up to the basement of the newly-formed lithosphere. The intrusive gabbro-granite magmatism of that time corresponds to the highest chlorine content and the formation of large-scale magnetite skarn mineralization. Along with the intraplate-type magmatic associations and rock series with intermediate features, this geodynamic setting is also characterized by a considerable amount of mantle-crust granitoids of the gabbro-tonalite-granodiorite-granite (GTGG) type formed with multiple manifestations of supra-subduction and crust (lowermost) anatectic processes. For these stages in the formation of the Hercynian South-Ural orogen, we have established a number of tectono-magmatic stages characterizing the magmatism of such tectonic events that accompanied the attachment of the Magnitogorsk Palaeo Arc and the eastward heterogeneous accretion assemblage to the margin of the East European Plate. Another goal of this paper is to typify the Permian granitoid magmatism, where mantle-crust gabbro-montzodiorite-granite latitic (282-274 Ma) and crust-palingenous granitic (290-276 Ma) and leucogranites (275-260 Ma) series were synchronously formed.

Methodology of geological zoning of orogenic belts, adequate to mobilistic paradigma, should be in a natural way correspond to geodynamics conception, taking into consideration the positions of lithospheric plate tectonics. For this purpose the methodology of tectonic-geodynamical zoning is being suggested. The base of such zoning is the distinguishing of zones with associations of one-type geodynamical regimes and environments and their structural combinations during the formation on the crust of oceanic type and localization in interplate position or on the boundaries of tectonic plates as a result of horizontal dislocations with the accretion and collision process manifestation. In its turn at the continental type crust in stable regimes folded systems have been formed. On this basis the particularities of tectonic-geodynamic zoning of the Ural-Timan-Paleoasian segment of Eurasia have been considered, general scheme of its zoning has been given as an example of the suggested methodology usage. A segment can be considered as a genotype of orogenic belts, being formed at the expense of the plate-tectonic accretion of oceanic basin on the craton periphery.

The article presents results of specialized processing of the deep seismic profile along a part of Reference Profile 3-DV which crosses the Aldan-Stanovoi shield in the meridian direction and goes across its buried northern slope. The study is aimed at determining frequency-energy characteristics of the seismic wave field which are related to physical conditions of geological features of the crust. Based on analysis and interpretation of the dynamic profiles, it is possible to reveal and contour the Archean cores of consolidation of the Aldan shield and its buried continuation that is covered by sediments of the Middle Lena monocline and to input new facts in the proposed geodynamic model showing formation of the crust in the south-eastern segment of the North Asian craton.

The terrain analysis concept envisages primarily a possibility of approximation of fragments / terrains of various geodynamic settings which belong to different plates. The terrain analysis can supplement the theory of plate tectonics in solving problems of geodynamics and tectonics of regions of the crust with complex structures. The Central Asian belt is among such complicated regions. Terrain structures occurred as a result of combined movements in the system of 'frontal' and/or oblique subduction – collision. In studies of geological objects, it is required first of all to prove their (vertical and horizontal) autochthony in relations to each other and then proceed to paleogeodynamic, paleotectonic and paleogeographic reconstructions. Obviously, such a complex approach needs data to be obtained by a variety of research methods, including those applied to study geologic structures, stratigraphy, paleontology, paleogeography, lithothlogy, geochemistry, geochronology, paleomagnetism etc. Only by correlating such data collected from inter-disciplinary studies of the regions, it is possible to establish reliable characteristics of the geological settings and avoid mistakes and misinterpretations that may be associated with the 'stratigraphic' approach to solutions of both regional and global problems of geodynamics and tectonics of folded areas. The terrain analysis of the Central Asian folded belt suggests that its tectonic structure combines marginal continental rock complexes that were formed by the evolution of two major oceanic plates. One of them is the plate of the Paleo-Asian Ocean. As the analogue of the current Indo-Atlantic segment of Earth, it is characterised by the presence of continental blocks in the composition of the oceanic crust and the formation of oceanic basins resulting from the breakup of Rodinia and Gondvana. In the course of its evolution, super-continents disintegrated, and the blocks were reunited into the Kazakhstan-Baikal continent. The base of the Kazakhstan-Baikal continent was formed in the Vend-Cambrian due to subduction of the oceanic crust of the Paleo-Asian Ocean, including the Precambrian microcontinents and terrains of the Gondvana group, underneath the south-eastern margin of the Siberian continent (in the current coordinates). Due to subduction followed by collision of the microcontinents with the Kazakhstan-Tuva-Mongolia island arc, the crust had consolidated, and a complex continent was formed. Another major plate is the plate of the Paleo-Pacific Ocean. It is characterized by the long-term tectono-magmatic evolution without any involvement of the continental crust and by complex processes of the formation of the continental margins. Its evolution resulted in the formation of the Vend-Paleozoic continental margin complexes of the western segment of the Siberian continent which comprise the Vend-Cambrian Kuznetsk-Altai island arc and a complex of rocks of the Ordovic-Early Devonian passive margin and the Devon-Early Carbonic active margin. In the accretional wedges of the Kuznetsk-Altai island arc, abundant are only fragments of the Vend-Early Cambrian oceanic crust including ophiolites and paleo-oceanic uplifts. The contemporary analogue of the Central Asian folded belt is the south-eastern margin of Asia, represented by the junction area of the Indo-Australian and Pacific plates.

Methodology of geological zoning of orogenic belts, adequate to mobilistic paradigma, should be in a natural way correspond to geodynamics conception, taking into consideration the positions of lithospheric plate tectonics. For this purpose the methodology of tectonic-geodynamical zoning is being suggested. The base of such zoning is the distinguishing of zones with associations of one-type geodynamical regimes and environments and their structural combinations during the formation on the crust of oceanic type and localization in interplate position or on the boundaries of tectonic plates as a result of horizontal dislocations with the accretion and collision process manifestation. In its turn at the continental type crust in stable regimes folded systems have been formed. On this basis the particularities of tectonic-geodynamic zoning of the Ural-Timan-Paleoasian segment of Eurasia have been considered, general scheme of its zoning has been given as an example of the suggested methodology usage. A segment can be considered as a genotype of orogenic belts, being formed at the expense of the plate-tectonic accretion of oceanic basin on the craton periphery.

The stationary accretion of dark energy onto black holes is studied. General expressions are derived for the accretion rate of an ideal fluid with an arbitrary equation of state and for scalar fields. The black hole mass was found to decrease for the accretion of phantom energy with p + ρ < 0. We also study the back reaction of accreting matter onto the metrics of a black hole in a perturbative way. The general expressions for corrections to the metric coefficients are found.