Related papers: Where are the young pulsars?
We collate the evidence for rotation-powered neutron stars that are visible as X-ray sources and not as radio pulsars. Quantitative upper limits exist for the radio fluxes of eight objects, revealing a population at least an order of…
The fact that the majority of the youngest radio pulsars are surrounded by expanding supernova remnants is strong evidence that neutron stars are produced in the supernovae of massive stars. In many cases, the pulsar appears significantly…
We examined the fall-back disk models, and in general accretion, proposed to explain the properties of anomalous X-ray pulsars (AXPs), soft gamma repeaters (SGRs), and radio pulsars (PSRs). We checked the possibility of some gas remaining…
A neutron star with mass close to the lower limit might be a reasonable model for some anomalous pulsars. Emission is thermal. X-ray luminosity is high. Spatial velocity can be high. Since the radius is predicted to be large, the magnetic…
The spin evolution of isolated neutron stars (NSs) is dominatd by their magnetic fields. The measured braking indices of young NSs show that the spin-down mechanism due to magnetic dipole radiation with constant magnetic fields is…
Some of the most interesting types of astrophysical objects that have been intensively studied in the recent years are the Anomalous X-ray Pulsars (AXPs) and Soft Gamma-ray Repeaters (SGRs) seen usually as neutron stars pulsars with super…
Both neutron stars and strange stars are capable of supporting fast rotations observed in pulsars. On the basis of this it has been argued that some of the pulsars could be strange stars. We investigate whether strange stars can sustain…
The similarity of rotation periods of, the anomalous X-ray pulsars (AXPs), the soft gamma ray repeaters (SGRs) and the dim thermal neutron stars (DTNs) suggests a common mechanism with an asymptotic spindown phase through the propeller and…
X-ray pulsars (XRPs) consist of a magnetized neutron star (NS) and an optical donor star. The NS accretes matter from the donor star producing pulsed X-ray emission. In most cases the donor stars are Be stars, and accretion is episodic,…
Recently, several accreting neutron stars (NSs) in X-ray binary systems inside supernova remnants have been discovered. They represent a puzzle for the standard magneto-rotational evolution of NSs, as their ages ($\lesssim 10^5$ years) are…
It is generally accepted that Anomalous X-ray Pulsars (AXPs) and Soft Gamma-ray Repeaters (SGRs) are magnetars, i.e. neutron stars with extremely high surface magnetic fields ($B > 10^{14}$ G). The origin of these high magnetic fields is…
Neutron Stars are among the most exotic objects in the Universe. A neutron star, with a mass of 1.4-2 Solar masses within a radius of about 10-15 km, is the most compact stable configuration of matter in which degeneracy pressure can still…
Rotating and magnetized protoneutron stars (PNSs) may drive relativistic magneto-centrifugally accelerated winds as they cool immediately after core collapse. The wind fluid near the star is composed of neutrons and protons, and the…
There exists a special class of X-ray pulsars that exhibit very slow pulsation of $P_{\rm spin}>1000$ s in the high mass X-ray binaries (HMXBs). We have studied the temporal and spectral properties of these superslow pulsation neutron star…
We investigate whether young neutron stars with fall-back disks can produce Anomalous X-Ray Pulsars (AXPs) within timescales indicated by the ages of associated supernova remnants. The system passes through a propeller stage before emerging…
Glitches are common phenomena in pulsars. After each glitch, there is usually a permanent increase in the pulsar's spin-down rate. Therefore a pulsar's present spin-down rate may be much higher than its initial value. Thus the…
Traditionally, studies aimed at inferring the distribution of birth periods of neutron stars are based on radio surveys. Here we propose an independent method to constrain the pulsar spin periods at birth based on their X-ray luminosities.…
Different pieces of observational evidence suggest the existence of disks around isolated neutron stars. Such disks could be formed from supernova fallback when neutron stars are born in core-collapse supernova explosions. Efforts have been…
I consider the state of play regarding associations of supernova remnants (SNRs) with anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs). The three AXP/SNR associations are convincing, and are consistent with AXPs being…
The Anomalous X-ray Pulsars (AXPs) are a small class of pulsars with spin periods in the 6-12 s range, very soft X-ray spectra, secular spin down on time scales of ~10^3-10^5 years, and lack of bright optical counterparts. Two, possibly…