Hadronic Gamma Rays from Supernova Remnants

A gas cloud near a supernova remnant (SNR) provides a target for pp-collisions leading to subsequent gamma-ray emission through neutral pion decay. The assumption of a power-law ambient spectrum of accelerated particles with index near -2 is usually built into models predicting the spectra of very-high energy (VHE) gamma-ray emission from SNRs. However, if the gas cloud is located at some distance from the SNR shock, this assumption is not necessarily correct. In this case, the particles which interact with the cloud are those leaking from the shock and their spectrum is approximately monoenergetic with the injection energy gradually decreasing as the SNR ages. In the GLAST energy range the gamma-ray spectrum resulting from particle interactions with the gas cloud will be flatter than expected, with the cutoff defined by the pion momentum distribution in the laboratory frame. We evaluate the flux of particles escaping from a SNR shock and apply the results to the VHE diffuse emission detected by the HESS at the Galactic centre.Comment: 4 pages, 3 figures. Contribution to the 30th ICRC, Merida, Mexico, 2007 (final version

On the mechanism for breaks in the cosmic ray spectrum

The proof of cosmic ray (CR) origin in supernova remnants (SNR) must hinge on full consistency of the CR acceleration theory with the observations; direct proof is impossible because of the orbit stochasticity of CR particles. Recent observations of a number of galactic SNR strongly support the SNR-CR connection in general and the Fermi mechanism of CR acceleration, in particular. However, many SNR expand into weakly ionized dense gases, and so a significant revision of the mechanism is required to fit the data. We argue that strong ion-neutral collisions in the remnant surrounding lead to the steepening of the energy spectrum of accelerated particles by \emph{exactly one power}. The spectral break is caused by a partial evanescence of Alfven waves that confine particles to the accelerator. The gamma-ray spectrum generated in collisions of the accelerated protons with the ambient gas is also calculated. Using the recent Fermi spacecraft observation of the SNR W44 as an example, we demonstrate that the parent proton spectrum is a classical test particle power law $\propto E^{-2}$, steepening to $E^{-3}$ at $E_{br}\approx7GeV$.Comment: APS talk to appear in PoP, 4 figure

Non linear particle acceleration at non-relativistic shock waves in the presence of self-generated turbulence

Particle acceleration at astrophysical shocks may be very efficient if magnetic scattering is self-generated by the same particles. This nonlinear process adds to the nonlinear modification of the shock due to the dynamical reaction of the accelerated particles on the shock. Building on a previous general solution of the problem of particle acceleration with arbitrary diffusion coefficients (Amato & Blasi, 2005), we present here the first semi-analytical calculation of particle acceleration with both effects taken into account at the same time: charged particles are accelerated in the background of Alfven waves that they generate due to the streaming instability, and modify the dynamics of the plasma in the shock vicinity.Comment: submitted to MNRA

Sensomotor integration features in skilled female boxers

The paper considers features of sensomotor integration of visuomotor reactions in female boxers. It is found that sportswomen have quicker reactions, but make more mistakes in complex choice reaction. Sensomotor integration of sensomotor reaction into functional systems of activity in female boxers is also associated more with accuracy of responsive actions than in reaction rate. © JPES

Dissipative Dynamics of Collisionless Nonlinear Alfven Wave Trains

The nonlinear dynamics of collisionless Alfven trains, including resonant particle effects is studied using the kinetic nonlinear Schroedinger (KNLS) equation model. Numerical solutions of the KNLS reveal the dynamics of Alfven waves to be sensitive to the sense of polarization as well as the angle of propagation with respect to the ambient magnetic field. The combined effects of both wave nonlinearity and Landau damping result in the evolutionary formation of stationaryOA S- and arc-polarized directional and rotational discontinuities. These waveforms are freqently observed in the interplanetary plasma.Comment: REVTeX, 6 pages (including 5 figures). This and other papers may be found at http://sdphpd.ucsd.edu/~medvedev/papers.htm

Proton-Helium Spectral Anomaly as a Signature of Cosmic Ray Accelerator

The much-anticipated proof of cosmic ray (CR) acceleration in supernova remnants (SNR) must hinge on full consistency of acceleration theory with the observations; direct proof is impossible because of the orbit scrambling of CR particles. The PAMELA orbital telescope revealed deviation between helium and proton CR spectra deemed inconsistent with the theory, since the latter does not differentiate between elements of ultrarelativistic rigidity. By considering an initial (injection-) phase of the diffusive shock acceleration (DSA), where elemental similarity does not apply, we demonstrate that the spectral difference is, in fact, a unique signature of the DSA. Collisionless plasma SNR shocks inject more He2+ relative to protons when they are stronger and so produce harder helium spectra. The injection bias is due to Alfven waves driven by the more abundant protons, so the He2+ ions are harder to trap by these waves because of the larger gyroradii. By fitting the p/He ratio to the PAMELA data, we bolster the DSA-case for resolving the century-old mystery of CR origin.Comment: PRL Accepted version: reformatted figures, references added, minor correction

Cosmic-ray acceleration in supernova remnants: non-linear theory revised

A rapidly growing amount of evidences, mostly coming from the recent gamma-ray observations of Galactic supernova remnants (SNRs), is seriously challenging our understanding of how particles are accelerated at fast shocks. The cosmic-ray (CR) spectra required to account for the observed phenomenology are in fact as steep as $E^{-2.2}--E^{-2.4}$, i.e., steeper than the test-particle prediction of first-order Fermi acceleration, and significantly steeper than what expected in a more refined non-linear theory of diffusive shock acceleration. By accounting for the dynamical back-reaction of the non-thermal particles, such a theory in fact predicts that the more efficient the particle acceleration, the flatter the CR spectrum. In this work we put forward a self-consistent scenario in which the account for the magnetic field amplification induced by CR streaming produces the conditions for reversing such a trend, allowing --- at the same time --- for rather steep spectra and CR acceleration efficiencies (about 20%) consistent with the hypothesis that SNRs are the sources of Galactic CRs. In particular, we quantitatively work out the details of instantaneous and cumulative CR spectra during the evolution of a typical SNR, also stressing the implications of the observed levels of magnetization on both the expected maximum energy and the predicted CR acceleration efficiency. The latter naturally turns out to saturate around 10-30%, almost independently of the fraction of particles injected into the acceleration process as long as this fraction is larger than about $10^{-4}$.Comment: 24 pages, 5 figures, accepted for publication in JCA

Analytic Solution for Self-regulated Collective Escape of Cosmic Rays from their Acceleration Sites

Supernova remnants (SNRs), as the major contributors to the galactic cosmic rays (CR), are believed to maintain an average CR spectrum by diffusive shock acceleration (DSA) regardless of the way they release CRs into the interstellar medium (ISM). However, the interaction of the CRs with nearby gas clouds crucially depends on the release mechanism. We call into question two aspects of a popular paradigm of the CR injection into the ISM, according to which they passively and isotropically diffuse in the prescribed magnetic fluctuations as test particles. First, we treat the escaping CR and the Alfven waves excited by them on an equal footing. Second, we adopt field aligned CR escape outside the source, where the waves become weak. An exact analytic self-similar solution for a CR "cloud" released by a dimmed accelerator strongly deviates from the test-particle result. The CR diffusion coefficient $D_{NL}$ is strongly suppressed compared to its background ISM value $D_{ISM}$: $D_{NL}\sim D_{ISM}\exp(-\Pi)<< D_{ISM}$ for sufficiently high field-line-integrated CR partial pressure, $\Pi$. When $\Pi>>1$, the CRs drive Alfven waves efficiently enough to build a transport barrier that strongly reduces the leakage. The solution has a spectral break at $p=p_{br}$, where $p_{br}$ satisfies the following equation $D_{NL}(p_{br})\simeq z^{2}/t$.Comment: 6 figures, aastex, 31 page

Intersystem interactions of physiological system indicators in students with different types of autonomic regulation

Studying not only individual students indicators of students, but complex intersystem interactions that reflect the specifics of adaptive capabilities is of scientific interest. The aim of the study. To reveal the features of intersystem interactions of indicators of the blood vessels functional state, morphological and neurodynamic characteristics of students with different types of autonomic regulation, living in the KhantyMansiysk Autonomous Okrug – Yugra. Methods. 429 first–fourth-year students (348 girls, 80 boys) of the Surgut State Pedagogical University were examined. The initial type of autonomic regulation was determined by the average duration of electrocardiogram RR intervals. Anthropometry parameters (body length and weight) and body composition were assessed using Tanita BC-601 device (Tanita, Japan), vascular wall elasticity – using AngioScan-01 (AngioScan-Electronics Ltd, Russia), neurodynamic indicators – using NS-PsychoTest device (Neurosoft, Russia). Statistical analysis was carried out using Statistica 7.0 software (StatSoft Inc., USA). We used the nonparametric Mann – Whitney U-test to evaluate differences and the nonparametric Pearson R-test to analyze correlations. Results. An increase in the stiffness of the vascular wall of large and small arteries in girls is  accompanied by an increase in parasympathetic activity. In young men, an  increase in the stiffness of large arteries raises with an increase in sympathoadrenal activity, while a  compensatory increase in the stiffness of small muscular arteries is noted with an increase in parasympathetic activity. In persons with the sympathicotonic type of autonomic regulation, an excess content of fat mass, an increased frequency of visceral obesity, and a deficiency in water content were registered. With the predominance of the parasympathetic component contribution to the regulation of cardiac rhythm, an increase in the processes of inhibition in the central nervous system was noted. In young men, reduced sensorimotor reactions are consistent with sympathetic activation in the regulation of heart rate. Correlation analysis made it possible to establish some features in the interaction of the vascular, morphological and central nervous systems. Conclusion. Differences in indicators of functional systems (physical development, blood flow, neurodynamic characteristics) in the examined groups of students are  shown, taking into account gender and autonomic regulation type. Features of intersystem interactions of indicators of physiological systems of students’ bodies with different types of autonomic regulation were revealed

Catalogues of variable binaries in the BDB, Binary star DataBase

База данных двойных звезд BDB, http://bdb.inasan.ru, объединяет данные каталогов двойных звезд всех наблюдательных типов. Мы описываем включение каталогов двойных переменных звезд в структуру базы данных.The BDB, Binary star DataBase http://bdb.inasan.ru combines data of the catalogues of binary stars of all observational types. We describe the implementation of catalogues of binary variable stars into the database structure.Работа выполнена при частичной поддержке гранта РФФИ 16-07-01162 и программы Президиума РАН №28 «Космос: исследования фундаментальных процессов и их взаимосвязей»