701 research outputs found
Do magnetars really exist?
It is shown that there are neither necessary nor sufficient properties to
provide unambiguous evidence for including any object in the AXP/SGR class.Comment: Proceedings of IAUS 291 "Neutron Stars and Pulsars: Challenges and
Opportunities after 80 years", J. van Leeuwen (ed.); 4 page
Drift Wave Model of Rotating Radio Transients
During the last few years there were discovered and deeply examined several
transient neutron stars (Rotating Radio Transients). It is already well
accepted that these objects are rotating neutron stars. But their extraordinary
features (burst-like behavior) made necessary revision of well accepted models
of pulsar interior structure. Nowadays most popular model for RRATs is
precessing pulsar model, which is the subject of big discussion. We assume that
these objects are pulsars with specific spin parameters. An important feature
of our model, naturally explaining most of the properties of these neutron
stars, is presence of very low frequency, nearly transverse drift waves
propagating across the magnetic field and encircling the open field lines
region of the pulsar magnetosphere.Comment: 9 pages, 3 figure
Coverage Problem Revisited
Motivated by some problems in genome assembling, we investigate properties of
spacings from absolutely continuous distributions. Several results on the
asymptotic behavior of the maximal uniform and non-uniform -spacings are
presented. Applications of these results to the coverage problem for the
prediction stage in genome assembling are also provided
Energy accumulation mechanism in pulsar magnetospheric plasma eigen-waves and formation of Giant Radio Pulses
In the present work we consider energy accumulation mechanism in relativistic
electron-positron plasma in the magnetosphere of pulsars. Waves propagating
almost across the magnetic field lines are generated that accumulate the energy
of plasma particles, as the waves stay significantly long in the resonance
region. The accumulated energy is transmitted in the parallel direction of the
magnetic field lines as soon as the non-linear plasma processes start to
operate. It is suggested that exit of the accumulated energy via waves
propagating along the magnetic field lines matching the viewing angle of the
observer produces giant pulses. It is shown that these waves come in the radio
domain, explaining the Giant Radio Pulse phenomenon.Comment: 6 pages, 2 figure
Radio pulsars with expected gamma radiation and gamma pulsars as pulsating radio emitters
Pulsars play a crucial astrophysical role as the highly energetic compact
radio, X-ray, and gamma-ray sources. Our previous works show that the radio
pulsars found as the pulsing gamma sources by the Large Area Telescope (LAT) on
the board of the Fermi Gamma-Ray Space Telescope have high values of magnetic
field near the light cylinder, two-three orders of magnitude stronger comparing
with the magnetic fields of radio pulsars: (G) are 3.60-3.95 and
1.75. Moreover, their losses of the rotation energy are also three orders
higher than the corresponding values for the main group of radio pulsars on
average: (erg/s) = 35.37-35.53 and 32.64. The correlation between
gamma-ray luminosities and radio luminosities is found. It allows us to select
those objects from all set of the known radio pulsars that can be detected as
gamma pulsars with the high probability. We give the list of such radio pulsars
and propose to search for gamma emisson from these objects. On the other hand,
the known catalog of gamma pulsars contains some sources which are not known as
radio pulsars at this moment. Some of them have the large values of gamma
luminosities and according to the obtained correlation, we can expect marked
radio emission from these objects. We give the list of such pulsars and
expected flux densities to search for radiation at frequencies 1400 and 111
MHz.Comment: Accepted by RA
On the Nature of Dark Matter and Dark Energy
It is shown that some problems connected with dark matter and dark energy can
be solved in the framework of the byuon theoryComment: 39 pages, 7 figure
Generation of nanoflares in the Crab pulsar
We study dynamics of drift waves in the pair plasma of pulsar magnetosphere.
It is shown that nonlinear of the drift waves with plasma particles leads to
the formation of small scale structures. We show that cyclotron instability
developed within these nonlinear structures can be responsible for the
formation of nanoshots discovered in the radio emission of the Crab pulsar.Comment: 16 page
On X-ray emission of radio pulsars
The analysis of distributions of some parameters of radio pulsars emitting
X-ray radiation was carried out. The majority of such pulsars has short spin
periods with the average value
= -19.69) and normal ( = -13.29) pulsars. Magnetic
fields at the surface of the neutron star are characterized by the bimodal
distribution as well. The mean values of are $8.48$ and $12.41$ for
millisecond pulsars and normal ones, respectively. The distribution of magnetic
fields near the light cylinder, it does not show the noticeable bimodality. The
median value of $log B_{lc}$ = 4.43 is almost three orders higher comparing
with this quantity ( = 1.75) for radio pulsars without registered
X-ray emission. Losses of rotational energy ( = 35.24)
are also three orders higher than corresponding values for normal pulsars.
There is the strong correlation between X-ray luminosities and losses of
rotational energies. The dependence of the X-ray luminosity on the magnetic
field at the light cylinder has been detected. It shows that the generation of
the non-thermal X-ray emission takes place at the periphery of the
magnetosphere and is caused by the synchrotron mechanism. We detected the
positive correlations between luminosities in radio, X-ray and gamma -ray
ranges. Such correlations give the possibility to carry out a purposeful search
for pulsars in one of these ranges if they radiate in other one.Comment: 16 pages, 11 figures, 1 tabl
Variations of decay rates of radio-active elements and their connections with global anisotropy of physical space
The analysis of correlations between fluctuations of alpha- and beta-decay
rates for different radio-active elements is carried out. These fluctuations
exceed significantly errors of measurements in many cases. They have the
periodical character and reveal definite spatial directions. We suggest that
the observed fluctuations are caused by the unique physical reason connected
with the global anisotropy of physical space and by the new force.Comment: 16 pages, 7 figure
Gep/Gmp for bound protons: first results for 16O with the recoil polarization technique
The first (e,e'p) polarization transfer measurements on a nucleus heavier
than deuterium have been carried out at Jefferson Laboratory. Transverse and
longitudinal components of the polarization of protons ejected in the reaction
16O(e,e'p) were measured in quasielastic perpendicular kinematics at a Q^2 of
0.8 (GeV/c)^2. The data are in good agreement with state of the art
calculations, but do not exclude possible changes in the ratio of the electric
to magnetic form factors of the nucleon in the nuclear medium at the level of
recent theoretical predictions.Comment: 5 pages, 2 figures, uses revtex.st
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