Compton effect on relativistic electrons in the atmosphere of the sun

Compton effect on relativistic electrons in solar atmospher

Broadband microwave burst produced by electron beams

Theoretical and experimental study of fast electron beams attracts a lot of attention in the astrophysics and laboratory. In the case of solar flares the problem of reliable beam detection and diagnostics is of exceptional importance. This paper explores the fact that the electron beams moving oblique to the magnetic field or along the field with some angular scatter around the beam propagation direction can generate microwave continuum bursts via gyrosynchrotron mechanism. The characteristics of the microwave bursts produced by beams differ from those in case of isotropic or loss-cone distributions, which suggests a new tool for quantitative diagnostics of the beams in the solar corona. To demonstrate the potentiality of this tool, we analyze here a radio burst occurred during an impulsive flare 1B/M6.7 on 10 March 2001 (AR 9368, N27W42). Based on detailed analysis of the spectral, temporal, and spatial relationships, we obtained firm evidence that the microwave continuum burst is produced by electron beams. For the first time we developed and applied a new forward fitting algorithm based on exact gyrosynchrotron formulae and employing both the total power and polarization measurements to solve the inverse problem of the beam diagnostics. We found that the burst is generated by a oblique beam in a region of reasonably strong magnetic field ($\sim 200-300$ G) and the burst is observed at a quasi-transverse viewing angle. We found that the life time of the emitting electrons in the radio source is relatively short, $\tau_l \approx 0.5$ s, consistent with a single reflection of the electrons from a magnetic mirror at the foot point with the stronger magnetic field. We discuss the implications of these findings for the electron acceleration in flares and for beam diagnostics.Comment: Astrophysical Journal, accepted: 26 pages, 8 figure

The role of labor potential in the sustainable development of the Russian Arctic

The key to the effective development of the Arctic resources is the active development of elements of the socio-economic systems of the Arctic territories. The progress in their use will provide a synergistic effect in the implementation of the full range of development priorities of the Arctic zone. One of these elements is labor potential, able to confront challenges in the Arctic effectively. Modern problems of the development of the labor potential of the Arctic territories are population decline, disruption of population reproduction processes, the low life expectancy of men and native people, social tensions in labor markets, and poverty. The provisions and conclusions of the presented study contain a scientifically substantiated position regarding the role of labor potential in the sustainable development of the Arctic territories of Russia. The research results are focused on their use for managing the development of the labor potential of the Arctic territories. Prospects for the further research of this topic are related to the study of the scientific foundations of the territorial self-development in achieving sustainable development of the Arctic territories of Russia

Threats to the Sustainable Development of the Russian Arctic: Poverty

The modern paradigm of the theory and practice of social development is the concept of sustainable development, the emergence and spread of which was associated with the emphasis on environmental pollution and overpopulation of the planet against the background of limited natural resources. Today, sustainable development is defined as the result of the interaction of a man, the economic system, and nature at the global, national, regional, and local levels. It is expressed, to a certain extent, by economic, environmental, and social sustainability. Modern goals in the field of sustainable development are to promote green growth, rational environmental management, ensuring access to quality health and education services, and improving the well-being of the population. The latter implies, first, the reduction of multidimensional poverty, the numerous groups of social localization, i.e., disabled people, families with children, single-parent families, and ethnic minorities. The aim of the study is to assess the level and extent of poverty and its social localization in the framework of achieving sustainable development of the regions of the Russian Arctic. The relevance of the study is determined by the fact that the rates and proportions of sustainable development of the Russian Arctic depend on the qualitative state of human potential (carried by the population). The qualitative state of human potential depends on the level of well-being of the population, which determines the degree of satisfaction of needs for benefits and access to social services. Poverty as a socio-economic phenomenon creates threats of degradation of human potential. The research hypothesis is based on the understanding that poverty is a systemic factor that limits the possibilities of a high-quality reproduction of human potential and, accordingly, promising opportunities for achieving sustainable development in the Russian Arctic. The research methods were a statistical analysis of the socio-economic situation of families with children in the regions of the Russian Arctic, as well as an analysis of regulatory legal documents governing measures of social support for families, motherhood, paternity, and childhood. The research results are focused on their use for achieving sustainable development of the Russian Arctic

Gamma-Ray Polarimetry of Two X-Class Solar Flares

We have performed the first polarimetry of solar flare emission at gamma-ray energies (0.2-1 MeV). These observations were performed with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) for two large flares: the GOES X4.8-class solar flare of 2002 July 23, and the X17-class flare of 2003 October 28. We have marginal polarization detections in both flares, at levels of 21% +/- 9% and -11% +/- 5% respectively. These measurements significantly constrain the levels and directions of solar flare gamma-ray polarization, and begin to probe the underlying electron distributions.Comment: 33 pages, 12 figures, accepted for publication in Ap

Neoliberal governance, sustainable development and local communities in the Barents Region

There are currently high hopes in the Barents Region for economic growth, higher employment and improved well-being, encouraged by developments in the energy industry, tourism and mining. The article discusses these prospects from the perspective of local communities in five locations in the region, which spans the northernmost counties of Finland, Norway, Sweden and Northwest Russia. The communities studied are remote, relatively small, multicultural, and dependent on natural resources. The salient dynamic illuminated in the research is how ideas of sustainability and neoliberal governance meet in community development. While the two governmentalities often conflict, they sometimes also complement one another, posing a paradox that raises concerns over the social aspect of sustainable development in particular. The article is based on international, multidisciplinary research drawing on interviews as well as statistical and documentary analysis

A field‐independent method for the rapid generation of hyperpolarized [1‐13C]Pyruvate in clean water solutions for biomedical applications

Hyperpolarization methods in magnetic resonance enhance the signals by several orders of magnitude, opening new windows for real-time investigations of dynamic processes in vitro and in vivo. Here, we propose a field-independent para-hydrogen-based pulsed method to produce rapidly hyperpolarized 13C-labeled substrates. We demonstrate the method by polarizing the carboxylic carbon of the pyruvate moiety in a purposely designed precursor to 24 % at ≈22 mT. Following a fast purification procedure, we measure 8 % polarization on free [1-13C]pyruvate in clean water solutions at physiological conditions at 7 T. The enhanced signals allow real-time monitoring of the pyruvate-lactate conversion in cancer cells, demonstrating the potential of the method for biomedical applications in combination with existing or developing magnetic resonance technologies

Inverse Compton X-rays from relativistic flare electrons and positrons

<p><b>Context:</b> In solar flares, inverse Compton scattering (ICS) of photospheric photons might give rise to detectable hard X-ray photon fluxes from the corona where ambient densities are too low for significant bremsstrahlung or recombination. γ-ray lines and continuum in some large flares imply the presence of the necessary ~100 MeV electrons and positrons, the latter as by-products of GeV energy ions. Recent observations of coronal hard X-ray sources in particular prompt us to reconsider here the possible contribution of ICS.</p> <p><b>Aims:</b> We aim to evaluate the ICS X-ray fluxes to be expected from prescribed populations of relativistic electrons and positrons in the solar corona. The ultimate aim is to determine if ICS coronal X-ray sources might offer a new diagnostic window on relativistic electrons and ions in flares.</p> <p><b>Methods:</b> We use the complete formalism of ICS to calculate X-ray fluxes from possible populations of flare primary electrons and secondary positrons, paying attention to the incident photon angular distribution near the solar surface and thus improving on the assumption of isotropy made in previous solar discussions.</p> <p><b>Results:</b> Both primary electrons and secondary positrons produce very hard ICS X-ray spectra. The anisotropic primary radiation field results in pronounced centre-to-limb variation in predicted fluxes and spectra, with the most intense spectra, extending to the highest photon energies, expected from limb flares. Acceptable numbers of electrons or positrons could account for RHESSI coronal X/γ-ray sources.</p> <p><b>Conclusions:</b> Some coronal X-ray sources at least might be interpreted in terms of ICS by relativistic electrons or positrons, particularly when sources appear at such low ambient densities that bremsstrahlung appears implausible.</p&gt