Radio recombination lines from the largest bound atoms in space

In this paper, we report the detection of a series of radio recombination lines (RRLs) in absorption near 26 MHz arising from the largest bound carbon atoms detected in space. These atoms, which are more than a million times larger than the ground state atoms are undergoing delta transitions (n~1009, Delta n=4) in the cool tenuous medium located in the Perseus arm in front of the supernova remnant, Cassiopeia A. Theoretical estimates had shown that atoms which recombined in tenuous media are stable up to quantum levels n~1500. Our data indicates that we have detected radiation from atoms in states very close to this theoretical limit. We also report high signal-to-noise detections of alpha, beta and gamma transitions in carbon atoms arising in the same clouds. In these data, we find that the increase in line widths with quantum number (proportional to n^5) due to pressure and radiation broadening of lines is much gentler than expected from existing models which assume a power law background radiation field. This discrepancy had also been noted earlier. The model line widths had been overestimated since the turnover in radiation field of Cassiopeia A at low frequencies had been ignored. In this paper, we show that, once the spectral turnover is included in the modeling, the slower increase in line width with quantum number is naturally explained.Comment: 5 pages, 4 figures, accepted for publication in MNRA

Radio Recombination Lines at Decametre Wavelengths: Prospects for the Future

This paper considers the suitability of a number of emerging and future instruments for the study of radio recombination lines (RRLs) at frequencies below 200 MHz. These lines arise only in low-density regions of the ionized interstellar medium, and they may represent a frequency-dependent foreground for next-generation experiments trying to detect H I signals from the Epoch of Reionization and Dark Ages ("21-cm cosmology"). We summarize existing decametre-wavelength observations of RRLs, which have detected only carbon RRLs. We then show that, for an interferometric array, the primary instrumental factor limiting detection and study of the RRLs is the areal filling factor of the array. We consider the Long Wavelength Array (LWA-1), the LOw Frequency ARray (LOFAR), the low-frequency component of the Square Kilometre Array (SKA-lo), and a future Lunar Radio Array (LRA), all of which will operate at decametre wavelengths. These arrays offer digital signal processing, which should produce more stable and better defined spectral bandpasses; larger frequency tuning ranges; and better angular resolution than that of the previous generation of instruments that have been used in the past for RRL observations. Detecting Galactic carbon RRLs, with optical depths at the level of 10^-3, appears feasible for all of these arrays, with integration times of no more than 100 hr. The SKA-lo and LRA, and the LWA-1 and LOFAR at the lowest frequencies, should have a high enough filling factor to detect lines with much lower optical depths, of order 10^-4 in a few hundred hours. The amount of RRL-hosting gas present in the Galaxy at the high Galactic latitudes likely to be targeted in 21-cm cosmology studies is currently unknown. If present, however, the spectral fluctuations from RRLs could be comparable to or exceed the anticipated H I signals.Comment: 9 pages; Astron. & Astrophys., in pres

The History of the Creation and Semantics of the Sacred Space of Ust-Medveditskiy Convent Caves in Volgograd Region

Introduction. The article presents the caves of Ust-Medveditsky St. Saviour convent in Volgograd region. The relevance of the research issue is in improving the recreational potential of the subject under study. The novelty of the work is in explaining the meaning of cave complex elements and the iconic stone with the image of knee and palm prints. The aim of the work is to study the history of creating the sacred space in the caves of Ust-Medveditsky convent. Herewith the work covers the following issues: 1) considering the history of creating caves by hegumeness Arseniya (Sebryakova); 2) clarification of the semantic meaning of some architectural elements in the cave complex in the context of creating the sacred space in the New Jerusalem of the Don region; 3) recommendations for developing the esthetical component of the caves, which increases the recreational potential for using the caves. Methods. In order to achieve the goals the author uses the structuralsemantic method, which allows to reveal the meaning of separate architectural elements in the caves in the structure of the cave complex. The system-based culturological method and the historical archaeological approach are used to understand the uniqueness of the object against the historical background of the dominating culture. The sources used to fulfill the objective include material ones such as architectural elements of the caves, written ones such as piligrimages, travellers’ notes about visits to the Holy Land, the biography of hegumeness Arseniya (Sebryakova). Analysis and Results. The caves under consideration were created in the second half of the 19th century by hegumeness Arseniya (Sebryakova). There was a sacred space of the Holy Land reconstructed: “Stations of the Cross” and “Sorrowful Way of the Holy Mother”. The stone with the image of knee and palm prints symbolizes the place where the Christ fell down after being arrested. Premise no. 8 with a step can symbolize the Holy Sepulcher with the tomb of Jesus. To improve the recreational potential of Ust- Medveditsky convent it is necessary to control microclimatic conditions, support the cave surface natural stone relief and colour, decorate the key sacred spaces with thematic icons

Digital receivers for low-frequency radio telescopes UTR-2, URAN, GURT

This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. Since 1998, digital receivers performing on-the-fly dynamic spectrum calculations or waveform data recording without data loss have been used at the UTR-2 radio telescope, the URAN VLBI system, and the GURT new generation radio telescope. Here we detail these receivers developed for operation in the strong interference environment that prevails in the decameter wavelength range. Data collected with these receivers allowed us to discover numerous radio astronomical objects and phenomena at low frequencies, a summary of which is also presented.Comment: 24 pages, 15 figure

Cold and Ultracold Rydberg Atoms in Strong Magnetic Fields

Cold Rydberg atoms exposed to strong magnetic fields possess unique properties which open the pathway for an intriguing many-body dynamics taking place in Rydberg gases consisting of either matter or anti-matter systems. We review both the foundations and recent developments of the field in the cold and ultracold regime where trapping and cooling of Rydberg atoms have become possible. Exotic states of moving Rydberg atoms such as giant dipole states are discussed in detail, including their formation mechanisms in a strongly magnetized cold plasma. Inhomogeneous field configurations influence the electronic structure of Rydberg atoms, and we describe the utility of corresponding effects for achieving tightly trapped ultracold Rydberg atoms. We review recent work on large, extended cold Rydberg gases in magnetic fields and their formation in strongly magnetized ultracold plasmas through collisional recombination. Implications of these results for current antihydrogen production experiments are pointed out, and techniques for trapping and cooling of such atoms are investigated.Comment: 46 pages, 38 figures, to appear in Physics Report

OBSERVATIONS OF DECAMETER CARBON RADIO RECOMBINATION LINES IN SEVERAL GALACTIC DIRECTIONS. Part 1. EXPERIMENTAL STUDY

Subject and Purpose. Since decameter carbon radio recombination lines (RRLs) were detected for the first time more than forty years ago, they have significantly extended our knowledge of the physics, kinematics and chemistry of the cold rarefied interstellar medium (ISM). A large number of these lines have been observed towards various Galactic radio sources. The present paper describes our studies of decameter carbon RRLs in such Galactic directions as the sight-lines to the S140 emission nebula and to the large volume of cold neutral hydrogen known as the GSH 139-03-69 super shell. Methods and Methodology. Observations within a 1-MHz frequency band centered at 26 MHz were performed using the UTR-2 radio telescope and a multi-channel digital correlator. The UTR-2 is still the world largest and the most sensitive low-frequency radio telescope. Results. We report the detection of decameter carbon RRL series C627α – C637α from the medium lying towards the S140 nebula. The extents of RRL forming regions have been estimated. It is suggested that RRLs in the S140 direction are formed in the local ISM lying along the line of sight. The RRL-forming region is probably associated with omnipresent diffuse neutral HI gas in the Galactic plane rather than with S140 nebula itself. Toward the GSH 139-03-69 super shell, decameter RRLs have been detected as well. Likewise, they apparently originate from the local medium lying along the sight-line. Yet, the spectrum contains a RRL component corresponding to the absorption of the cold gas of the GSH 139-03-69 itself in the ISM. Conclusions. The obtained results indicate great possibilities of decameter carbon RRLs not only for cold ISM probing but also for making a good auxiliary tool for studying large complexes of extremely cold hydrogen HI in the Galaxy

Энтропия собственности в западной и российской правовой доктрине и практике

The subject of the study is a phenomenon of an “entropy” of property, its interpretation, socio-economic conditionality, genesis of its development in European and Russian doctrine, reflection of a construct of “separated” property in the legislation. “Entropy” of property is a situation when both entities are owners, but in different areas of relations: the first person is the owner in relation to third parties, and the second-in relation to the first The goal of this scientific research is to find out reasons of the existence of phenomenon of “entropy of property” in European and Russian legal doctrines, to identify common and specific features of this phenomenon. Methodology. The authors use the general scientific method, including dialectics, comparative analysis, formal logic, historical method. A number of specific methods pertaining to the legal science were used as well: the formal dogmatic method was applied for analysis of ownership within the institute of property rights; the logical legal method was applied to study general tendencies of development of the institute of property rights; the legal comparative method was used to study European and Russian legislation on ownership and other property rights. The main scientific results. The Western legal doctrine of “entropy of property” has quite a long history of development, unlike the Russian. Specific features of the Russian doctrine are result of its historical, political and cultural characteristics. The phenomenon of “entropy of property” has both positive and negative consequences, which requires pluralistic approach to its assessment. “Reunification” of ownership rights on the land plot and other objects located on it, is a result of socio-economic and legal factors and deserves positive assessment. Property rights as elements of titular possession are not based only on law, but may be created by contract as well. Conclusions. The European and Russian legal doctrines on the “entropy of property” have both common and specific features. The common features are: existence of “absolute” ownership, limited property rights, trends of reunification of “separated” property etc. The specific features are: absence of “trust” in the Russian legal system; excessive fragmentation of right of ownership as a large “bundle” of rights; absence of situations when one person may simultaneously hold statuses of owner and holder of a limited property right in the Russian legislation.Рассматриваются концептуальное содержание категории «энтропия собственности», ее генезис от «функциональной» собственности к собственности «абсолютной» в западной и российской доктрине, влияние на формирование современной конструкции права собственности и других вещных прав, их типизацию. Анализируются теоретические тенденции к выработке подходов к обеспечению защиты вещных прав; попытки рецепции в российском правопорядке англосаксонской модели «траста»; проблемы «воссоединения» «расщепленной» собственности в правопорядках европейских стран, а также России – в контексте современного реформирования института вещных прав

Мониторинг радиационной обстановки на территории Воронежской области

The purpose of the study was to assess the doses of personnel and the population at the expense of all the main activities and sources of radiation in the territory of the Voronezh region. The data of the forms of state statistical supervision No. 1-DOZ “Information on the doses of personnel from persons under normal use of technogenic sources of ionizing radiation”, No. 3-DOZ “Information on radiation doses of patients during X-ray radiology studies”), No. 4-DOZ “Information on radiation doses of the population due to natural and technogenically altered background” for 2010-2016 and the radiation and hygienic passport of the territory of the Voronezh Region. Based on the results of monitoring the radiation situation, the situation associated with the impact of ionizing radiation sources in the Voronezh Region has been characterized as safe for the past 7 years. The average annual effective dose per 1 inhabitant due to all ionizing radiation remains stable with a slight upward trend and lies in the range from 2.925 (2010) to 3.399 mSv (2016). In the structure of the collective dose of the population of the Voronezh region, the dose from natural sources is 83.65%, from medical sources – 16.06%, from technogenically changed background radiation, including global fallout and accident at the Chernobyl nuclear power plant – 0.18%, from the activities of enterprises using Sources of ionizing radiation – 0.11%. The average annual effective dose of natural exposure to humans varies from 0.660 to 0.704 mSv / year, natural radiation from radon from 0.832 to 1.465 mSv / year. The average effective dose from medical research for the procedure for the study period was 0.27-0.40 mSv and tends to decrease due to the introduction of modern low-dose medical diagnostic equipment. On the territory of the Voronezh region, there were no population groups with an effective radiation dose exceeding 5 mSv / year. Gamma-background in the region in 2010-2016. Did not exceed the natural level and amounted to 0.08 – 0.16 μSv / h. The excess of hygienic standards for the effects of ionizing radiation sources on humans has not been recorded.Целью исследования являлась оценка доз облучения персонала и населения за счет всех основных видов деятельности и источников облучения на территории Воронежской области. Использованы данные форм государственного статистического наблюдения №1-ДОЗ «Сведения о дозах облучения лиц из персонала в условиях нормальной эксплуатации техногенных источников ионизирующих излучений», № 3-ДОЗ «Сведения о дозах облучения пациентов при проведении рентгено-радиологических исследований», № 4-ДОЗ «Сведения о дозах облучения населения за счет естественного и техногенно измененного фона» за 2010–2016 гг. и радиационно-гигиенического паспорта территории Воронежской области. По результатам мониторинга радиационной обстановки ситуация, связанная с воздействием источников ионизирующего излучения в Воронежской области на протяжении последних 7 лет характеризуется как безопасная. Величина средней годовой эффективной дозы на 1 жителя за счет всех видов ионизирующего излучения остается стабильной с небольшой тенденцией увеличения и лежит в интервале от 2,925 (2010 г.) до 3,399 мЗв (2016 г.). В структуре коллективной дозы населения Воронежской области доза от природных источников составля-ет 83,65%, от медицинских – 16,06%, от техногенно измененного радиационного фона, включая глобальные выпадения и аварию на Чернобыльской АЭС – 0,18%, от деятельности предприятий, использующих источники ионизирующего излучения, – 0,11%. Средняя годовая эффективная доза природного облучения человека варьирует от 0,660 до 0,704 мЗв/год, природного облучения человека от радона – от 0,832 до 1,465 мЗв/год. Средняя эффективная доза от медицинских исследований за процедуру за период исследования составляла 0,27–0,40 мЗв и имеет тенденцию к снижению за счет внедрения современного малодозового медицинского диагностического оборудования. На территории Воронежской области отсутствовали группы населения с эффективной дозой облучения свыше 5 мЗв/год. Гамма-фон на территории области в 2010–2016 гг. не превысил естественного уровня и составил 0,08–0,16 мкЗв/ч. Превышений гигиенических нормативов воздействия источников ионизирующего излучения на человека не зарегистрировано

ОЦЕНКА ПОСЛЕДСТВИЙ РАДИАЦИОННОГО ЗАГРЯЗНЕНИЯ ТЕРРИТОРИИ ВОРОНЕЖСКОЙ ОБЛАСТИ ЗА ТРИДЦАТИЛЕТНИЙ ПЕРИОД ПОСЛЕ ЧЕРНОБЫЛЬСКОЙ КАТАСТРОФЫ

The study aimed at radiation contamination impact assessment due to the 1986 Chernobyl accident in Voronezh Region territory more than 600 kilometers away from the ground zero. The major Chernobyl accident impact assessment indicators were the characteristics of 137Cs and 90Sr radionuclides’ soil surface contamination (Ci/km2) as well as the average annual effective dose of critical population group ( mSv/year) over 1986–2014. The Population oncological morbidity indicators were analyzed (all malignant neoplasms, including those in thyroid gland, lymphatic and hematopoietic tissue) in the territories contrastingly differing on the levels of radiation factor impact. The study covered the period of 2010–2014.It was established that for Voronezh Region territories referred to as the post- Chernobyl radioactively contaminated zone over 29 years period the maximum soil surface contamination by 137Cs and 90Sr radionuclides reduced by 1.90 and 1.91 times (from 3,15 Ci/km2 to 1,66 Ci/km2 and from 0,063 Ci/km2 to 0,0033 Ci/km2, respectively).Currently the relationship was not found between the radioactive contamination density in Voronezh Region and the levels of malignant neoplasms for the local residents.The present situation related to radiation factor impact on Voronezh Region territories remains stable and safe. Mindful of the indicators results the assessment of ionizing sources impact did not identify any exceeding the normative values.Целью исследования являлась оценка последствий радиационного загрязнения от Чернобыльской катастрофы 1986 г. на территории Воронежской области, удаленной от эпицентра более чем на 600 км. Основными показателями для оценки воздействия Чернобыльской аварии на территорию Воронежской области были выбраны характеристики поверхностной загрязненности почвы радионуклидами 137Cs и 90Sr (Ки/км2), а также среднегодовая эффективная доза критической группы населения (мЗв/год) за 1986–2014 гг. Выполнен анализ показателей онкологической заболеваемости населения (все злокачественные новообразования, в том числе щитовидной железы, лимфатической и кроветворной ткани) на территориях, контрастных по уровням воздействия радиационного фактора за 2010–2014 гг.Установлено, что для территорий Воронежской области, отнесенных к зоне радиоактивного загрязнения вследствие катастрофы на Чернобыльской АЭС, за двадцатидевятилетний период произошло снижение максимальных значений поверхностной загрязненности почвы радионуклидами 137Cs и 90Sr 1,90 и 1,91 раз (с 3,15 до 1,66 Ки/км2 и с 0,063 до 0,0033 Ки/км2 соответственно).В настоящее время связи между плотностью радиоактивного загрязнения территорий Воронежской области и уровнем злокачественных новообразований у населения, проживающего на них, не установлено.Ситуация, связанная с воздействием радиационного фактора, на территории Воронежской области в настоящее время остается стабильной и безопасной. По результатам оценки показателей, характеризующих уровень воздействия источников ионизирующего излучения, превышений нормативов не зарегистрировано