362 research outputs found

    The Spectral Type of the Ionizing Stars and the Infrared Fluxes of HII Regions

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    The 20 cm radio continuum fluxes of 91 HII regions in a previously compiled catalog have been determined. The spectral types of the ionizing stars in 42 regions with known distances are estimated. These spectral types range from B0.5 to O7, corresponding to effective temperatures of 29 000-37 000 K. The dependences of the infrared (IR) fluxes at 8, 24, and 160 ΞΌ\mum on the 20 cm flux are considered. The IR fluxes are used as a diagnostic of heating of the matter, and the radio fluxes as measurements of the number of ionizing photons. It is established that the IR fluxes grow approximately linearly with the radio flux. This growth of the IR fluxes probably indicates a growth of the mass of heated material in the envelope surrounding the HII region with increasing effective temperature of the star.Comment: 16, pages, 10 figures, published in Astronomy Report

    Gas kinematics in massive star-forming regions from the Perseus spiral arm

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    We present results of a survey of 14 star-forming regions from the Perseus spiral arm in CS(2-1) and 13CO(1-0) lines with the Onsala Space Observatory 20 m telescope. Maps of 10 sources in both lines were obtained. For the remaining sources a map in just one line or a single-point spectrum were obtained. On the basis of newly obtained and published observational data we consider the relation between velocities of the "quasi-thermal" CS(2-1) line and 6.7 GHz methanol maser line in 24 high-mass star-forming regions in the Perseus arm. We show that, surprisingly, velocity ranges of 6.7 GHz methanol maser emission are predominantly red-shifted with respect to corresponding CS(2-1) line velocity ranges in the Perseus arm. We suggest that the predominance of the "red-shifted masers" in the Perseus arm could be related to the alignment of gas flows caused by the large-scale motions in the Galaxy. Large-scale galactic shock related to the spiral structure is supposed to affect the local kinematics of the star-forming regions. Part of the Perseus arm, between galactic longitudes from 85deg to 124deg, does not contain blue-shifted masers at all. Radial velocities of the sources are the greatest in this particular part of the arm, so the velocity difference is clearly pronounced. 13CO(1-0) and CS(2-1) velocity maps of G183.35-0.58 show gas velocity difference between the center and the periphery of the molecular clump up to 1.2 km/s. Similar situation is likely to occur in G85.40-0.00. This can correspond to the case when the large-scale shock wave entrains the outer parts of a molecular clump in motion while the dense central clump is less affected by the shock.Comment: accepted by Astronomy Report

    Molecular Emission in Dense Massive Clumps from the Star-Forming Regions S231-S235

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    The article deals with observations of star-forming regions S231-S235 in 'quasi-thermal' lines of ammonia (NH3_3), cyanoacetylene (HC3_3N) and maser lines of methanol (CH3_3OH) and water vapor (H2_2O). S231-S235 regions is situated in the giant molecular cloud G174+2.5. We selected all massive molecular clumps in G174+2.5 using archive CO data. For the each clump we determined mass, size and CO column density. After that we performed observations of these clumps. We report about first detections of NH3_3 and HC3_3N lines toward the molecular clumps WB89 673 and WB89 668. This means that high-density gas is present there. Physical parameters of molecular gas in the clumps were estimated using the data on ammonia emission. We found that the gas temperature and the hydrogen number density are in the ranges 16-30 K and 2.8-7.2Γ—103\times10^3 cmβˆ’3^{-3}, respectively. The shock-tracing line of CH3_3OH molecule at 36.2 GHz is newly detected toward WB89 673.Comment: 16 pages, 4 figure

    Molecular gas in high-mass filament WB673

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    We studied the distribution of dense gas in a filamentary molecular cloud containing several dense clumps. The center of the filament is given by the dense clump WB673. The clumps are high-mass and intermediate-mass star-forming regions. We observed CS(2-1), 13CO(1-0), C18O(1-0) and methanol lines at 96GHz toward WB673 with the Onsala Space Observatory 20-m telescope. We found CS(2-1) emission in the inter-clump medium so the clumps are physically connected and the whole cloud is indeed a filament. Its total mass is 10410^4 MβŠ™_{\odot} and mass-to-length ratio is 360 MβŠ™_{\odot}pcβˆ’1^{-1} from 13CO(1-0) data. Mass-to-length ratio for the dense gas is 3.4βˆ’343.4-34 MβŠ™_{\odot}pcβˆ’1^{-1} from CS(2-1) data. The PV-diagram of the filament is V-shaped. We estimated physical conditions in the molecular gas using methanol lines. Location of the filament on the sky between extended shells suggests that it could be a good example to test theoretical models of formation of the filaments via multiple compression of interstellar gas by supersonic waves

    The status of world outlook and environmental competencies in aerospace engineering training: the general and special

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    The article is devoted to the study of the status of philosophical and environmental competences for engineering education programs in the field of space exploration. The authors prove that the specialists who will work in the space field in the XXI century face the most important problems, the solution of which is vital for humanity. It is stated that the quality of future decisions will be determined by the development of the philosophical and environmental ideas. It is demonstrated that these idea should necessarily have futurological character. It is suggested that the special courses aimed at the formation of futurological philosophical and environmental concepts can present as a possible solution to this problem (e.g. Creativity training for engineers, etc.)

    The role and future outlook for renewable energy in the Arctic zone of Russian Federation

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    The development of the Arctic zone of the Russian Federation (the Russian Arctic) aims to enhance the social and economic growth of the region in line with the priorities set forth by the state policy and address a range of socio-economic issues. As the Russian Arctic offers an array of hydrocarbons and renewables available in the context of the region's unbalanced infrastructural and manufacturing development and extreme climatic environment, the conditions dictate the need for an integrated use of the Arctic's energy resources. Energy security of a region is a primary contributor to its social and economic sustainability. Key energy users in the Russian Arctic include both large and local load consumers that have to operate against the background of economic and logistic difficulties related to power supply. The Russian Arctic can offer a wide range of energy resources, but individual areas are facing power shortage. These challenges are particularly relevant for the Arctic regions in Siberia and the Far East, and to a lesser extent for the Murmansk and Arkhangelsk regions as the areas are covered by the capabilities of the Unified Energy System of Russia. Energy challenges and discrepant development plans for the power and manufacturing sectors create major barriers that slow down the social and economic development of the areas. Our analysis demonstrated that the role of unconventional and renewable energy in power generation and energy mix of the Russian Arctic will remain insignificant in the short term.peer-reviewe

    Effect of polyethylene glycol immobilized into a polymethacrylate matrix on the sorption of rhodamine

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    Combined matrix PMMA and PEG, having a polymethacrylate backbone and hydrophilic PEG chains, has been synthesized and applied for the design of transparent colour sensors. Introduction of the hydrophilic PEG chains in the PMMA bulk overcomes the limitations caused by the hydrophobicity of PMMA, and exhibits good wettability, stable and specific adsorption. We suppose that the adsorption of rhodamine on such networks depends on the chemical composition of the system and describes the interaction of the xanthene dye with the polymers

    Epistemological risk aspects

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    The paper considers risk in the context of the main characteristics of non-classical epistemology. It states that non-classical epistemology is characterized by transformation, according to which the major priority of cognitive activity shifts the focus from the present to the past. In this situation a subject is keen not on what he or she has learnt but on what can be learnt. Truth being a crucial criterion of scientific knowledge is becoming of less priority, while risk is becoming more and more significant and acts as one of the major epistemology measurements. Risk is gaining the status of epistemological phenomenon, which shows a growing degree of uncertainty as a cognitive process background and the necessity for a subject to learn the world (make decisions) under the conditions of uncertainty degree strengthening. The author states that risk is a comprehensive notion and it obtains a base value for all other aspects of its application, specifically, in the role of epistemological phenomenon
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