Related papers: The Magnificent Seven: Close-by Cooling Neutron St…
We model populations of isolated neutron stars in the Galaxy following their orbital and magneto-rotational evolution. It is shown that accretors become more abundant than coolers at fluxes below $\sim 10^{-13}$ erg cm$^{-2}$ s$^{-1},$ and…
As many as $10^9$ neutron stars populate the Galaxy, but only $\approx 10^3$ are directly observed as pulsars or as accreting sources in X-ray binaries. In principle also the accretion of the interstellar medium may make isolated neutron…
We present limits to the log N - log S curve for isolated neutron stars, both cooling and accreting neutron stars, which are not active as radio pulsars, as observed with the ROSAT All-Sky Survey and compare it with theoretical…
Observations of cooling neutron stars allow to measure photospheric radii and to constrain the equation of state of nuclear matter at high densities. In this paper we concentrate on neutron stars, which show thermal (photospheric) X-ray…
The contribution of weakly--magnetized ($B\sim 10^9$ G) neutron stars accreting the interstellar medium to the diffuse X--ray emission observed in the Galactic Center is investigated. It is shown that, under rather conservative assumptions…
ROSAT has discovered a new group of isolated neutron stars characterized by soft black-body like spectra (kT ~ 50-120 eV), apparent absence of radio emission and no association with supernovae remnants. So far only six such sources are…
Old isolated accreting neutron stars may show up among unidentified soft X--ray sources detected by the ROSAT All Sky Survey. We argue that the chances of identification are greater for ONSs located in the closest overdense regions of the…
Presently seven nearby radio-quiet isolated neutron stars discovered in ROSAT data and characterized by thermal X-ray spectra are known. They exhibit very similar properties and despite intensive searches their number remained constant…
We study thermal states of transiently accreting neutron stars (with mean accretion rates $\dot{M} \sim 10^{-14}-10^{-9}$ M$_\odot$ yr$^{-1}$) determined by the deep crustal heating of accreted matter sinking into stellar interiors. We…
We study evolution of isolated neutron stars on long time scale and calculate distribution of these sources in the main evolutionary stages: Ejector, Propeller, Accretor, and Georotator. We compare different initial magnetic field…
We present Log N -- Log S distribution for close-by young isolated neutron stars. On the basis of this distribution it is shown that the seven ROSAT isolated neutron stars (if they are young cooling objects) are genetically related to the…
Nuclear reactions occurring deep in the crust of a transiently accreting neutron star efficiently maintain the core at a temperature >5e7 K. When accretion halts, the envelope relaxes to a thermal equilibrium set by the flux from the hot…
The cooling theory of neutron stars is corroborated by its comparison with observations of thermally emitting isolated neutron stars and accreting neutron stars in binary systems. An important ingredient for such an analysis is the age of…
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…
Although the true origin of the broad absorption lines in X-ray spectra of thermal isolated neutron stars is not clear yet, our current knowledge about the "magnificent seven" strongly suggests that they are highly magnetized ($10^{13} -…
With a simple model from the point of view of population synthesis we try to verify an interesting suggestion made by Pfahl & Rappaport (2001) that dim sources in globular clusters (GCs) can be isolated accreting neutron stars (NSs). Simple…
Ages and thermal luminosities of neutron stars, inferred from observations, can be interpreted with the aid of the neutron star cooling theory to gain information on the properties of superdense matter in neutron-star interiors. We present…
We perform population synthesis modeling of isolated neutron stars in the Milky Way over its lifetime. Compared with previous studies, we use more detailed models of the interstellar medium and the magneto-rotational evolution of neutron…
In accreting neutron star X-ray transients, the neutron star crust can be substantially heated out of thermal equilibrium with the core during an accretion outburst. The observed subsequent cooling in quiescence (when accretion has halted)…
Using recently calculated analytic models for the thermal structure of ultramagnetized neutron stars, we estimate the thermal fluxes from young ($t\sim 1000$ yr) ultramagnetized ($B \sim 10^{15}$ G) cooling neutron stars. We find that the…