相关论文: Why pulsars rotate and move: kicks at birth
We propose that the bimodal nature of the kick velocity distribution of radio pulsars is connected with the dichotomy between hadronic stars ({\it i.e.} neutron stars with no quark matter content) and quark stars. Bimodality can appear due…
We study observational constraints on neutron star (NS) kicks for isolated pulsars and for neutron stars in binary systems. We are particularly interested in the evidence of kick-spin alignment/misalignment and its dependence on the neutron…
Using energy conservation we show that if a sudden external force of unknown nature causes a newborn pulsar of mass $M=1.4 M_\odot$ and radius R=10 km to have the acceleration $a_0$ then we can derive the relation $a_0\simeq…
We explore the enigmatic population of long-period, apparently non-recycled pulsars in globular clusters, building on recent work by Boyles et al (2011). This population is difficult to explain if it formed through typical core collapse…
Recent discoveries by the Rossi X-Ray Timing Explorer indicate that most of the rapidly accreting and weakly magnetic neutron stars in the Galaxy are rotating at spin frequencies greater than 250 Hz. Remarkably, they all rotate in a narrow…
High velocity neutron stars, observed as rapidly moving radio-pulsars, are believed to gain high linear velocities -- kicks -- in aspherical supernova explosions. The mechanism of the kick formation is probably connected with anisotropic…
We propose a new neutrino propulsion mechanism for neutron stars which can lead to strong velocity kicks, needed to explain the observed bimodal velocity distribution of pulsars. The spatial asymmetry in the neutrino emission is naturally…
The existence of pulsars with spin period below one millisecond is expected, though they have not been detected up to now. Their formation depends on the quantity of matter accreted from the companion which, in turn, is limited by the…
Recent observations have unveiled a population of pulsars with spin periods of a few minutes to hours that lie beyond the traditional ``death line.'' If they originate from neutron stars (NSs), the existence of such ultra-long period…
Radio pulsars are thought to spin-down primarily due to torque from magnetic dipole radiation (MDR) emitted by the time-varying stellar magnetic field as the star rotates. This assumption yields a `characteristic age' for a pulsar which has…
The paucity of old isolated accreting neutron stars in ROSAT observations is used to derive a lower limit on the mean velocity of neutron stars at birth. The secular evolution of the population is simulated following the paths of a…
Pulsar motions in our Galaxy from their birth until 2 Gyr are studied statistically via Monte-Carlo simulation of $2\times 10^5$ pulsars with the best available representation of the Galactic potential. We find that the distribution of…
We present results of a binary population synthesis study on the orbital period distribution of wide binary millisecond pulsars forming through four evolutionary channels. In three of the channels, the progenitor of the millisecond pulsar…
A millisecond pulsar is a neutron star that has been substantially spun up by accretion from a binary companion. A previously unrecognized factor governing the spin evolution of such pulsars is the crucial effect of non-steady or transient…
Supernovae, the explosive deaths of massive stars, create heavy elements and form black holes and neutron stars. These compact objects often receive a velocity at formation, a "kick" whose physical origin remains debated. We investigate…
We discuss the mean-field dynamo action in protoneutron stars that are subject to instabilities during the early evolutionary phase. The mean field is generated in the neutron-finger unstable region where the Rossby number is $\sim 1$ and…
Binary and Millisecond pulsars have a great deal to teach us about stellar evolution and are invaluable tools for tests of relativistic theories of gravity. Our understanding of these objects has been transformed by large-scale surveys that…
The speeds of young isolated pulsars are generally inferred from their observed 2-d velocities on the plane of the sky under the assumption that the unobserved radial velocity is not special, i.e., that the measured 2-d velocity is an…
We investigate the statistics of isolated recycled pulsars and double neutron star binaries in the Galactic disk. Since recycled pulsars are believed to form through accretion and spinup in close binaries, the isolated objects presumably…
The origin of high velocities of pulsars is studied by considering the spin-flip conversion of neutrinos propagating in a gravitational field of a protoneutron star. For a rotating gravitational source (such as pulsars) with angular…