Abstract
Measurements of starlight polarized by aligned interstellar dust grains are used to probe the relation between the orientation of the ambient interstellar magnetic field (ISMF) and the ISMF ...traced by the ribbons of energetic neutral atoms discovered by the Interstellar Boundary Explorer spacecraft. We utilize polarization data, many acquired specifically for this study, to trace the configuration of the ISMF within 40 pc. A statistical analysis yields a best-fit ISMF orientation,
B
magpol
, aligned with Galactic coordinates
ℓ
= 42°,
b
= 49°. Further analysis shows the ISMF is more orderly for “downfield” stars located over 90° from
B
magpol
. The data subset of downfield stars yields an orientation for the nearby ISMF at ecliptic coordinates
λ
,
β
≈ 219° ± 15°, 43° ± 9° (Galactic coordinates
l
,
b
≈ 40°, 56°, ±17°). This best-fit ISMF orientation from polarization data is close to the field direction obtained from ribbon models. This agreement suggests that the ISMF shaping the heliosphere belongs to an extended ordered magnetic field. Extended filamentary structures are found throughout the sky. A previously discovered filament traversing the heliosphere nose region, “Filament A,” extends over 300° of the sky, and crosses the upwind direction of interstellar dust flowing into the heliosphere. Filament A overlaps the locations of the Voyager kilohertz emissions, three quasar intraday variables, cosmic microwave background (CMB) components, and the inflow direction of interstellar grains sampled by Ulysses and Galileo. These features are likely located in the upstream outer heliosheath where ISMF drapes over the heliosphere, suggesting Filament A coincides with a dusty magnetized plasma. A filament 55° long is aligned with a possible shock interface between local interstellar clouds. A dark spot in the CMB is seen within 5° of the filament and within 10° of the downfield ISMF direction. Two large magnetic arcs are centered on the directions of the heliotail. The overlap between CMB components and the aligned dust grains forming Filament A indicates the configuration of dust entrained in the ISMF interacting with the heliosphere provides a measurable foreground to the CMB.
The
aim and objectives
of the article are to analyze fraudulent phishing schemes and develop recommendations for Internet use and relevant regulatory tasks. The
relevance
of the article is due to the ...peculiarities of working in cyberspace with the emergence of new sources of banking risks, both for customers and organizations. The
scientific
novelty of the manuscript consists of a detailed analysis of phishing schemes, the development of recommendations and directions in relation to the Russian Federation. The
object
of the study is cyber fraud in the credit and financial sphere; the
subject
is social engineering and phishing schemes. The
methodology
of the paper includes a systematic analysis of the literature and sources on the research topic, general scientific methods (analysis, synthesis, deduction, analogy, classification), correlation analysis of data, graphical visualization of information. The authors
consider
the main methods of phishing and the most common techniques used by cybercriminals. Based on the critical analysis of the literature the authors determined a promising direction for the scientific and technical potential of Russia. A correlation analysis of the relationship between the number of cybercrimes and commercial banks is performed. The study offers
recommendations
to Internet users (how to recognize the signs of fraud), and to regulatory bodies on improving the system of supervision over the dissemination of information in cyberspace. The authors
concluded
that it is necessary to increase the level of cyber literacy and general literacy of the population, on the one hand, and to modernize the methods of supervision and control of the information posted on the Internet, on the other hand, to effectively counter financial and cybercrime. The research
results
can be used in the further development of remote banking services for the population to increase competitiveness in the banking services market.
Prospects
for further research on this topic lie in expanding its structure, developing the competencies of specialists in the field of remote banking technologies, as well as developing the scientific and technical potential of Russia.
Detection of magnetic focusing peaks allows probing of minibands in the energy spectrum of twisted bilayer graphene.
Magnetic fields force ballistic electrons injected from a narrow contact to move ...along skipping orbits and form caustics. This leads to pronounced resistance peaks at nearby voltage probes as electrons are effectively focused inside them, a phenomenon known as magnetic focusing. This can be used not only for the demonstration of ballistic transport but also to study the electronic structure of metals. Here, we use magnetic focusing to probe narrowbands in graphene bilayers twisted at ~2°. Their minibands are found to support long-range ballistic transport limited at low temperatures by intrinsic electron-electron scattering. A voltage bias between the layers causes strong minivalley splitting and allows selective focusing for different minivalleys, which is of interest for using this degree of freedom in frequently discussed valleytronics.
We report the first direct detection of an exoplanet in the visible polarized light. The transiting planet HD 189733b is one of the very hot Jupiters with shortest periods and, thus, smallest orbits, ...which makes them ideal candidates for polarimetric detections. We obtained polarimetric measurements of HD 189733 in the B band well distributed over the orbital period and detected two polarization maxima near planetary elongations with a peak amplitude of similar to 2 x 10 sub(-4). Assuming Rayleigh scattering, we estimated the effective size of the scattering atmosphere (Lambert sphere) to be 1.5 plus or minus 0.2 R sub(J), which is 30% larger than the radius of the opaque body previously inferred from transits. If the scattering matter fills the planetary Roche lobe, the lower limit of the geometrical albedo can be estimated as 0.14. The phase dependence of polarization indicates that the planetary orbit is oriented almost in a north-south direction with a longitude of ascending node Omega = (16 degree or 196 degree ) plus or minus 8 degree . We obtain independent estimates of the orbit inclination i = 98 degree plus or minus 8 degree and eccentricity e = 0.0 (with an uncertainty of 0.05), which are in excellent agreement with values determined previously from transits and radial velocities. Our findings clearly demonstrate the power of polarimetry and open a new dimension in exploring exoplanetary atmospheres even for systems without transits.
A
bstract
The cross section of the process
e
+
e
−
→
π
+
π
−
has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000
e
+
e
−
collider VEPP-2000 in the energy region 525
...<
s
<
883 MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb
−
1
. The systematic uncertainty of the cross section determination is 0.8% at
s
>
0
.
600 GeV. The
ρ
meson parameters are obtained as
m
ρ
= 775
.
3 ± 0
.
5 ± 0
.
6 MeV, Γ
ρ
= 145
.
6 ± 0
.
6 ± 0
.
8 MeV,
B
ρ
→
e
+
e−
×
B
ρ
→
π
+
π−
= (4
.
89 ± 0
.
02 ± 0
.
04) × 10
−
5
, and the parameters of the
e
+
e
−
→
ω
→
π
+
π
−
process, suppressed by
G
-parity, as
B
ω
→
e
+
e−
×
B
ω
→
π
+
π−
= (1
.
32 ± 0
.
06 ± 0
.
02) × 10
−
6
and and
ϕ
ρω
= 110
.
7 ± 1
.
5 ± 1
.
0 degrees.
Aims. Following our recent discovery of a new magnetic DQ white dwarf (WD) with CH molecular features, we report the results for the rest of the DQ WDs from our survey. Methods. We use high ...signal-to-noise spectropolarimetric data to search for magnetic fields in a sample of 11 objects. Results. One object in our sample, WD1235+422, shows the signs of continuum circular polarization that is similar to some peculiar DQs with unidentified molecular absorption bands, but the low signal-to-noise ratio and spectral resolution of these data make more observations necessary to reveal the true nature of this object.
Context. We investigate the linear polarization produced by interstellar dust aligned by the magnetic field in the solar neighborhood (d < 50 pc). We also look for intrinsic effects from ...circumstellar processes, specifically in terms of polarization variability and wavelength dependence. Aims. We aim to detect and map dust clouds which give rise to statistically significant amounts of polarization of the starlight passing through the cloud, and to determine the interstellar magnetic field direction from the position angle of the observed polarization. Methods. High-precision broad-band (BV R) polarization observations are made of 361 stars in spectral classes F to G, with detection sensitivity at the level of or better than 10−5 (0.001%). The sample consists of 125 stars in the magnitude range 6–9 observed at the 2.2 m UH88 telescope on Mauna Kea, 205 stars in the magnitude range 3–6 observed at the Japanese (Tohoku) T60 telescope on Haleakala, and 31 stars in the magnitude range 4–7 observed at the 1.27 m H127 telescope of the Greenhill Observatory, Tasmania. Identical copies of the Dipol-2 polarimeter are used on these three sites. Results. Statistically significant (>3σ) polarization is found in 115 stars, and >2σ detection in 178 stars, out of the total sample of 361 stars. Polarization maps based on these data show filament-like patterns of polarization position angles, which are related to both the heliosphere geometry, the kinematics of nearby clouds, and the Interstellar Boundary EXplorer ribbon magnetic field. From long-term multiple observations, a number (~20) of stars show evidence of intrinsic variability at the 10−5 level. This can be attributed to circumstellar effects (e.g., debris disks and chromospheric activity). The star HD 101805 shows a peculiar wavelength dependence, indicating size distribution of scattering particles different from that of a typical interstellar medium. Our high signal-to-noise measurements of nearby stars with very low polarization also provide a useful dataset for calibration purposes.
Abstract
This paper considers the development and application of a system of reflectometry for the analysis of the homogeneity of structures manufactured by additive technologies. A system of ...reflectometry based on a backward wave oscillator, a two-dimensional object positioning system and an optoacoustic detector (Goley cell) is described. The results of reflectometry of the hexagonal periodic structure of cells based on acrylonitrile butadiene styrene at a wavelength of 343 microns are presented.
PDF
