575 research outputs found
Source energy spectra from demodulation of solar particle data by interplanetary and coronal transport
The data on source energy spectra of solar cosmic rays (SCR), i.e. the data on the spectrum form and on the absolute SCR are of interest for three reasons: (1) the SCR contain the energy comparable to the total energy of electromagnetic flare radiation (less than or equal to 10 to the 32nd power ergs); (2) the source spectrum form indicates a possible acceleration mechanism (or mechanism); and (3) the accelerated particles are efficiently involved in nuclear electromagnetic and plasma processes in the solar atmosphere. Therefore, the data on SCR source spectra are necessary for a theoretical description of the processes mentioned and for the formulation of the consistent flare model. Below it is attempted to sound solar particle sources by means of SCR energy spectrum obtained near the Sun, at the level of the roots of the interplanetary field lines in the upper solar corona. Data from approx. 60 solar proton events (SPE) between 1956-1981. These data were obtained mainly by the interplanetary demodulation of observed fluxes near the Earth. Further, a model of coronal azimuthal transport is used to demodulate those spectra, and to obtain the source energy spectra
Off-resonance field enhancement by spherical nanoshells
We study light scattering by spherical nanoshells consistent of
metal/dielectric composites. We consider two geometries of metallic nanoshell
with dielectric core, and dielectric coated metallic nanoparticle. We
demonstrate that for both geometries the local field enhancement takes place
out of resonance regions ("dark states"), which, nevertheless, can be
understood in terms of the Fano resonance. At optimal conditions the light is
stronger enhanced inside the dielectric material. By using nonlinear dielectric
materials it will lead to a variety nonlinear phenomena applicable for
photonics applications
Properties and nature of Be stars: 27. Orbital and recent long-term variations of the Pleiades Be star Pleione = BU Tauri
Radial-velocity variations of the H-alpha emission measured on the steep
wings of the H-alpha line, prewhitened for the long-time changes, vary
periodically with a period of (218.025 +/- 0.022)d, confirming the suspected
binary nature of the bright Be star Pleione, a member of the Pleiades cluster.
The orbit seems to have a high eccentricity over 0.7, but we also briefly
discuss the possibility that the true orbit is circular and that the
eccentricity is spurious owing to the phase-dependent effects of the
circumstellar matter. The projected angular separation of the spectroscopic
orbit is large enough to allow the detection of the binary with large optical
interferometers, provided the magnitude difference primary - secondary is not
too large. Since our data cover the onset of a new shell phase up to
development of a metallic shell spectrum, we also briefly discuss the recent
long-term changes. We confirm the formation of a new envelope, coexisting with
the previous one, at the onset of the new shell phase. We find that the full
width at half maximum of the H-alpha profile has been decreasing with time for
both envelopes. In this connection, we briefly discuss Hirata's hypothesis of
precessing gaseous disk and possible alternative scenarios of the observed
long-term changes
Skin effect with arbitrary specularity in Maxwellian plasma
The problem of skin effect with arbitrary specularity in maxwellian plasma
with specular--diffuse boundary conditions is solved. A new analytical method
is developed that makes it possible to to obtain a solution up to an arbitrary
degree of accuracy. The method is based on the idea of symmetric continuation
not only the electric field, but also electron distribution function. The
solution is obtained in a form of von Neumann series.Comment: 7 pages, 2 figure
Applied bachelor degree programme as the direction of mobile social teachers training in the conditions of professional and mobile practice
The relevance is caused by the need to train mobile social teachers with a high level of adaptation to the changing working conditions and capable timely, reasonably, optimally and quickly to solve social and pedagogical problems of people of different age and social categories. The purpose of the article is in defining the role of applied bachelor degree in training of mobile social teachers in the conditions of professional - mobile practice. The leading method is comparative analysis of social teachers training in the conditions of state educational standard of 2005 and new generation standard FGOS-2010. The article presents the method of projects as the leading kind of activity of practice-oriented training in the direction of applied bachelor degree of future social teachers in the conditions of practice. The method of project activity can be realized in training of specialists in different direction of training and profile. © 2019 by the authors
The Asymmetrical Wind of the Candidate Luminous Blue Variable MWC 314
We present the results of long-term spectropolarimetric and spectroscopic
monitoring of MWC 314, a candidate Luminous Blue Variable star. We detect the
first evidence of H variability in MWC 314, and find no apparent
periodicity in this emission. The total R-band polarization is observed to vary
between 2.21% and 3.00% at a position angle consistently around
, indicating the presence of a time-variable intrinsic
polarization component, hence an asymmetrical circumstellar envelope. We find
suggestive evidence that MWC 314's intrinsic polarization exhibits a
wavelength-independent magnitude varying between 0.09% and 0.58% at a
wavelength-independent position angle covering all four quadrants of the Stokes
Q-U plane. Electron scattering off of density clumps in MWC 314's wind is
considered as the probable mechanism responsible for these variations.Comment: 19 pages, 6 figures, accepted in PAS
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Photometric observations of the radio bright B[e]/X-ray binary CI Cam
We present multiwavelength (optical, IR, radio) observations of CI Cam, the optical counterpart to the transient X-ray source XTE J0421+560. Pre-outburst quiescent observations reveal the presence of a dusty envelope around the system. Pronounced short term variability is observed at all wavebands from U-K, but no indication of prior flaring of a similar magnitude to the 1998 April outburst is found in these data.
Data obtained during the 1998 April X-ray flare reveal pronounced optical-radio flaring. The optical flux was observed to quickly return to quiescent levels, while the radio flare was of much longer duration. The optical component is likely to result from a combination of free-free/free-bound emission, emission line and thermal dust emission, caused by re-radiation of the X-ray flux, while the behaviour of the multiwavelength radio data is consistent with emission from expanding ejecta emitting via the synchrotron mechanism.
Post-outburst (1998 August-1999 March) U-M broadband photometric observations reveal that while the optical (UBV) flux remains at pre-outburst quiescent levels, near IR (JHKLM) fluxes exceed the pre-outburst fluxes by ~0.5 magnitudes. Modelling the pre- and post-outburst spectral energy distribution of CI Cam reveals that the structure and/or composition of the dusty component of the circumstellar envelope appears to have changed. Due to a lack of information on the precise chemical composition of the dust within the system several explanations for this behaviour are possible, such as the production of new dust at the inner edge of the envelope, or modification of the composition of the dust due to X-ray irradiation
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