Observational constraints on the modeling of SN1006

Experimental spectra and images of the supernova remnant SN1006 have been reported for radio, X-ray and TeV gamma-ray bands. Several comparisons between models and observations have been discussed in the literature, showing that the broad-band spectrum from the whole remnant as well as a sharpest radial profile of the X-ray brightness can be both fitted by adopting a model of SN1006 which strongly depends on the non-linear effects of the accelerated cosmic rays; these models predict post-shock magnetic field (MF) strengths of the order of 150 micro G. Here we present a new way to compare models and observations, in order to put constraints on the physical parameters and mechanisms governing the remnant. In particular, we show that a simple model based on the classic MHD and cosmic rays acceleration theories allows us to investigate the spatially distributed characteristics of SN1006 and to put observational constraints on the kinetics and MF. Our method includes modelling and comparison of the azimuthal and radial profiles of the surface brightness in radio, hard X-rays and TeV gamma-rays as well as the azimuthal variations of the electron maximum energy. In addition, this simple model also provides good fits to the radio-to-gamma-ray spectrum of SN1006. We find that our best-fit model predicts an effective MF strength inside SN1006 of 32 micro G, in good agreement with the `leptonic' model suggested by the HESS Collaboration (2010). Finally, some difficulties in both the `classic' and the non-linear models are discussed. A number of evidences about non-uniformity of MF around SN1006 are noted.Comment: 15 pages, 13 figures, accepted for publication on MNRA

Some properties of synchrotron radio and inverse-Compton gamma-ray images of supernova remnants

The synchrotron radio maps of supernova remnants (SNRs) in uniform interstellar medium and interstellar magnetic field (ISMF) are analyzed, allowing different `sensitivity' of injection efficiency to the shock obliquity. The very-high energy gamma-ray maps due to inverse Compton process are also synthesized. The properties of images in these different wavelength bands are compared, with particular emphasis on the location of the bright limbs in bilateral SNRs. Recent H.E.S.S. observations of SN 1006 show that the radio and IC gamma-ray limbs coincide, and we found that this may happen if: i) injection is isotropic but the variation of the maximum energy of electrons is rather quick to compensate for differences in magnetic field; ii) obliquity dependence of injection (either quasi-parallel or quasi-perpendicular) and the electron maximum energy is strong enough to dominate magnetic field variation. In the latter case, the obliquity dependence of the injection and the maximum energy should not be opposite. We argue that the position of the limbs alone and even their coincidence in radio, X-rays and gamma-rays, as it is discovered by H.E.S.S. in SN 1006, cannot be conclusive about the dependence of the electron injection efficiency, the compression/amplification of ISMF and the electron maximum energy on the obliquity angle.Comment: Accepted for publication in MNRA

Effects of non-uniform interstellar magnetic field on synchrotron X-ray and inverse-Compton gamma-ray morphology of SNRs

Observations of SNRs in X-ray and gamma-ray bands promise to contribute with important information in our understanding on the nature of galactic cosmic rays. The analysis of SNRs images collected in different energy bands requires the support of theoretical modeling of synchrotron and inverse Compton (IC) emission. We develop a numerical code (REMLIGHT) to synthesize, from MHD simulations, the synchrotron radio, X-ray and IC gamma-ray emission from SNRs expanding in non-uniform interstellar medium (ISM) and/or non-uniform interstellar magnetic field (ISMF). As a first application, the code is used to investigate the effects of non-uniform ISMF on the SNR morphology in the non-thermal X-ray and gamma-ray bands. We perform 3D MHD simulations of a spherical SNR shock expanding through a magnetized ISM with a gradient of ambient magnetic field strength. The model includes an approximate treatment of upstream magnetic field amplification and the effect of shock modification due to back reaction of accelerated cosmic rays. From the simulations, we synthesize the synchrotron radio, X-ray and IC gamma-ray emission with REMLIGHT, making different assumptions about the details of acceleration and injection of relativistic electrons. A gradient of the ambient magnetic field strength induces asymmetric morphologies in radio, X-ray and gamma-ray bands independently from the model of electron injection if the gradient has a component perpendicular to the line-of-sight. The degree of asymmetry of the remnant morphology depends on the details of the electron injection and acceleration and is different in the radio, X-ray, and gamma-ray bands. The non-thermal X-ray morphology is the most sensitive to the gradient, showing the highest degree of asymmetry. The IC gamma-ray emission is weakly sensitive to the non-uniform ISMF, the degree of asymmetry of the SNR morphology being the lowest in this band.Comment: 16 pages, 13 Figures; accepted for publication on A&A. Version with full resolution images can be found at http://www.astropa.unipa.it/~orlando/PREPRINTS/sorlando_15505.pd

Linking gamma-ray spectra of supernova remnants to the cosmic ray injection properties in the aftermath of supernovae

The acceleration times of the highest-energy particles which emit gamma-rays in young and middle-age SNRs are comparable with SNR age. If the number of particles starting acceleration was varying during early times after the supernova explosion then this variation should be reflected in the shape of the gamma-ray spectrum. We use the solution of the non-stationary equation for particle acceleration in order to analyze this effect. As a test case, we apply our method to describe gamma-rays from IC443. As a proxy of the IC443 parent supernova we consider SN1987A. First, we infer the time dependence of injection efficiency from evolution of the radio spectral index in SN1987A. Then, we use the inferred injection behavior to fit the gamma-ray spectrum of IC443. We show that the break in the proton spectrum needed to explain the gamma-ray emission is a natural consequence of the early variation of the cosmic ray injection, and that the very-high energy gamma-rays originate from particles which began acceleration during the first months after the supernova explosion. We conclude that the shape of the gamma-ray spectrum observed today in SNRs critically depends on the time variation of the cosmic ray injection process in the immediate post explosion phases. With the same model, we estimate also the possibility in the future to detect gamma-rays from SN 1987A.Comment: A&A, accepte

Radio polarization maps of shell-type SNRs II. Sedov models with evolution of turbulent magnetic field

Polarized radio emission has been mapped with great detail in several Galactic supernova remnants (SNRs), but has not yet been exploited to the extent it deserves. We have developed a method to model maps of the Stokes parameters for shell-like SNRs during their Sedov evolution phase. At first, 3-dimensional structure of a SNR has been computed, by modeling the distribution of the magnetohydrodynamic parameters and of the accelerated particles. The generation and dissipation of the turbulent component of magnetic field everywhere in SNR are also considered taking into account its interaction with accelerated particles. Then, in order to model the emission, we have used a generalization of the classical synchrotron theory, valid for the case in which the magnetic field has ordered and disordered components. Finally, 2-dimensional projected maps have been derived, for different orientations of SNR and of interstellar magnetic field with respect to the observer. An important effect to consider is the Faraday rotation of the polarization planes inside the SNR interior. In this paper we present details of the model, and describe general properties of the images.Comment: accepted in MNRA

On the Origin of Asymmetries in Bilateral Supernova Remnants

AIMS: We investigate whether the morphology of bilateral supernova remnants (BSNRs) observed in the radio band is determined mainly either by a non-uniform interstellar medium (ISM) or by a non-uniform ambient magnetic field. METHODS: We perform 3-D MHD simulations of a spherical SNR shock propagating through a magnetized ISM. Two cases of shock propagation are considered: 1) through a gradient of ambient density with a uniform ambient magnetic field; 2) through a homogeneous medium with a gradient of ambient magnetic field strength. From the simulations, we synthesize the synchrotron radio emission, making different assumptions about the details of acceleration and injection of relativistic electrons. RESULTS: We find that asymmetric BSNRs are produced if the line-of-sight is not aligned with the gradient of ambient plasma density or with the gradient of ambient magnetic field strength. We derive useful parameters to quantify the degree of asymmetry of the remnants that may provide a powerful diagnostic of the microphysics of strong shock waves through the comparison between models and observations. CONCLUSIONS: BSNRs with two radio limbs of different brightness can be explained if a gradient of ambient density or, most likely, of ambient magnetic field strength is perpendicular to the radio limbs. BSNRs with converging similar radio arcs can be explained if the gradient runs between the two arcs.Comment: 14 pages, 8 Figures; paper accepted for publication in A&A; the paper with high-resolution figures can be downloaded at http://www.astropa.unipa.it/~orlando/PAPERS/sorlando_6045.pd

Разработка методического инструмента повышения конкурентоспособности международной деятельности университета

The improvement of Russian higher education competitiveness is a strategic task for the country socio-economic development. The higher school trains experts who will have to solve the complex tasks faced by the country economy, and provide a technological breakthrough. At that it should be noted that the modern graduate should have skills in the global economy. The implementation of measures improving the competitiveness of Russian higher education is faced with a number of restrictions caused by the global economic development. One of the main limitations is state funding reduction for universities, which forces them to seek new sources of resources, including the external market. This leads to increased competition between universities for applicants. It should be noted that competition is not limited only to the national market, it acquires an international character. In developed economies, higher education is one of the sources of export earnings. Besides, foreign countries recruit qualified labor through international educational projects. One of the tools to improve the competitiveness of university is its international activity. On this basis, it follows that the development of methodological tools for international activity management in a higher education institution is an urgent task today.La mejora de la competitividad de la educación superior rusa es una tarea estratégica para el desarrollo socioeconómico del país. La escuela superior capacita a expertos que tendrán que resolver las complejas tareas que enfrenta la economía del país y proporcionar un avance tecnológico. En eso debe tenerse en cuenta que el graduado moderno debe tener habilidades en la economía global. La implementación de medidas que mejoran la competitividad de la educación superior rusa se enfrenta a una serie de restricciones causadas por el desarrollo económico global. Una de las principales limitaciones es la reducción de fondos estatales para las universidades, lo que las obliga a buscar nuevas fuentes de recursos, incluido el mercado externo. Esto lleva a una mayor competencia entre las universidades por los solicitantes. Cabe señalar que la competencia no se limita solo al mercado nacional, sino que adquiere un carácter internacional. En las economías desarrolladas, la educación superior es una de las fuentes de ingresos de exportación. Además, los países extranjeros reclutan mano de obra calificada a través de proyectos educativos internacionales. Una de las herramientas para mejorar la competitividad de la universidad es su actividad internacional. Sobre esta base, se deduce que el desarrollo de herramientas metodológicas para la gestión de la actividad internacional en una institución de educación superior es una tarea urgente hoy en día.Повышение конкурентоспособности российского высшего образования является стратегической задачей социально-экономического развития страны. Высшая школа готовит специалистов, которым предстоит решать сложные задачи, стоящие перед экономикой страны, и обеспечивать технологический прорыв. При этом следует отметить, что современный выпускник должен обладать навыками в мировой экономике. Реализация мер по повышению конкурентоспособности российского высшего образования сталкивается с рядом ограничений, обусловленных глобальным экономическим развитием. Одним из основных ограничений является сокращение государственного финансирования университетов, что заставляет их искать новые источники ресурсов, в том числе на внешнем рынке. Это приводит к усилению конкуренции между университетами за абитуриентов. Следует отметить, что конкуренция не ограничивается только национальным рынком, она приобретает международный характер. В развитых экономиках высшее образование является одним из источников экспортных поступлений. Кроме того, зарубежные страны привлекают квалифицированную рабочую силу в рамках международных образовательных проектов. Одним из инструментов повышения конкурентоспособности университета является его международная деятельность. Исходя из этого, из этого следует, что разработка методологических инструментов управления международной деятельностью в вузе является актуальной задачей на сегодняшний день

Russian Migration and Psychological Aspect

The problem of regional migration is treated in the article. The development of the Far Eastern territories is a priority now. The government has developed many large-scale projects aimed at supporting the remote region, but the problem of emigration of the economically active population has not settled since 1991. The problem of the outflow of promising young personnel from its territory is particularly acute. The purpose of this research is to study the reasons for the migration of young people from the Primorsky Region - one of the regions of the Far East. The main tasks were to obtain visions of migration moods and motivation of migration behavior of students. The study used a psychological verbal-communicative method - a survey in which a specially designed list of questions was used as a means to collect information from the respondent. The survey covered about 1,000 respondents between the ages of 15 and 30.  The research has shown that the main reason for emigration of school graduates is the opportunity to progress, studying in prestigious domestic and foreign universities, working in the largest Russian and foreign companies, that not enough represented here. Excellent and good rated school graduates prefer to enter Moscow and St. Petersburg universities. This means that most prospective workers in the future want to leave the territory of the region. Analysis of the responses of the university graduates revealed the prevalence of negative expectations about their future and the future of the territories. The data indicated that the main reasons to leave the country and the Primorsky Region are low job prospects for university graduates, lack of self-realization possibilities, low wages and the instability of the region’s political and socio-economic situation. In addition, the situation is exacerbated by the fact that respondents, for the most part, do not know about the projects that are being implemented in the region and do not see career prospects, which confirms the implementation of many strategic projects of the region only on paper. The lack of measures to prevent the emigration of young people will have a number of negative economic and social consequences, one of which is the reduction of competitevness of the territory. Creating favorable conditions for young people in the region, active public policy to attract young skilled professionals in Primorye is a prerequisite for the development of the region's intellectual capital and a guarantee of its dynamic socio-economic development.The problem of regional migration is treated in the article. The development of the Far Eastern territories is a priority now. The government has developed many large-scale projects aimed at supporting the remote region, but the problem of emigration of the economically active population has not settled since 1991. The problem of the outflow of promising young personnel from its territory is particularly acute. The purpose of this research is to study the reasons for the migration of young people from the Primorsky Region - one of the regions of the Far East. The main tasks were to obtain visions of migration moods and motivation of migration behavior of students. The study used a psychological verbal-communicative method - a survey in which a specially designed list of questions was used as a means to collect information from the respondent. The survey covered about 1,000 respondents between the ages of 15 and 30.  The research has shown that the main reason for emigration of school graduates is the opportunity to progress, studying in prestigious domestic and foreign universities, working in the largest Russian and foreign companies, that not enough represented here. Excellent and good rated school graduates prefer to enter Moscow and St. Petersburg universities. This means that most prospective workers in the future want to leave the territory of the region. Analysis of the responses of the university graduates revealed the prevalence of negative expectations about their future and the future of the territories. The data indicated that the main reasons to leave the country and the Primorsky Region are low job prospects for university graduates, lack of self-realization possibilities, low wages and the instability of the region’s political and socio-economic situation. In addition, the situation is exacerbated by the fact that respondents, for the most part, do not know about the projects that are being implemented in the region and do not see career prospects, which confirms the implementation of many strategic projects of the region only on paper. The lack of measures to prevent the emigration of young people will have a number of negative economic and social consequences, one of which is the reduction of competitevness of the territory. Creating favorable conditions for young people in the region, active public policy to attract young skilled professionals in Primorye is a prerequisite for the development of the region's intellectual capital and a guarantee of its dynamic socio-economic development