Related papers: RX J1856.5-3754: A strange star with solid quark s…
We investigate the stability of strange quark matter and the properties of the corresponding strange stars, within a wide range of quark mass scaling. The calculation shows that the resulting maximum mass always lies between 1.5 solor mass…
The state of cold quark matter really challenges both astrophysicists and particle physicists, even many-body physicists. It is conventionally suggested that BCS-like color superconductivity occurs in cold quark matter; however, other…
Applying the ideas and methods of condensed matter physics we calculate the quantum conductivity of quark matter in magnetic field. In strong field quantum conductivity is proportional to the square root of the field.
Strange quark matter in beta equilibrium at high densities is studied in a quark confinement model. Two equations of state are dynamically generated for the {\it same} set of model parameters used to describe the nucleon: one corresponds to…
We show that within a recently developed nonlocal chiral quark model the critical density for a phase transition to color superconducting quark matter under neutron star conditions can be low enough for these phases to occur in compact star…
Results of photometric and spectroscopic investigations of the recently discovered disc cataclysmic variable star 1RXS J180834.7+101041 are presented. Emission spectra of the system show broad double peaked hydrogen and helium emission…
Color superconductivity in quark matter is studied for electrically charge neutral neutron star matter in $\beta$-equilibrium. Both bulk quark matter and mixed phases of quark and nuclear matter are treated. The electron chemical potential…
We present a 45 ks Chandra observation of the quasar ULAS J1342+0928 at z=7.54. We detect 14.0^{+4.8}_{-3.7} counts from the quasar in the observed-frame energy range 0.5-7.0 keV (6-sigma detection), representing the most distant…
We present results from a 20 ks XMM-Newton DDT observation of the radio-load quasar CFHQS J142952+544717 at z=6.18, whose extreme X-ray luminosity was recently revealed by the SRG/eROSITA telescope in the course of its first all-sky survey.…
A spectral analysis of the nearby isolated neutron star RX J1856.5-3754 is presented. Applying the kinetic approach, the distribution functions of emitting electrons are derived and the entire spectra is fitted. It is found that waves…
We report on a detailed spectral analysis of all the available XMM-Newton data of RX J1856.5-3754, the brightest and most extensively observed nearby, thermally emitting neutron star. Very small variations (~1-2%) in the single-blackbody…
The densest predicted state of matter is colour-superconducting quark matter, in which quarks near the Fermi surface form a condensate of Cooper pairs. This form of matter may well exist in the core of compact stars, and the search for…
A broad sample of computed realistic equations of state of superdense matter with quark phase transition is used to construct a series of models neutron stars with a strange quark core. The integral characteristics of the stellar…
It has been predicted that quark and hybrid stars, containing strange quark matter in their core, have a significantly smaller radius than ordinary neutron stars. Preliminary X-ray observations of isolated neutron stars indicated a…
We show that the Coulomb barrier at the quark surface of a hot strange star may be a powerful source of $e^+e^-$ pairs which are created in an extremely strong electric field of the barrier and flow away from the star. The luminosity in the…
In June 2003 the isolated neutron star RX J185635-3754 will pass within 0.3'' of a 26.5 mag star, changing its position by about 0.6 mas. The displacement, caused by gravitational lensing, will be proportional to the neutron star mass. The…
The recent observation of the pulsar PSR J1614-2230 with a mass of 1.97 +/- 0.04 M_sun gives a strong constraint on the quark and nuclear matter equations of state (EoS). We explore the parameter ranges for a parameterized EoS for quark…
3XMM J185246.6+003317 is a transient magnetar located in the vicinity of the supernova remnant Kes\,79. So far, observations have only set upper limits to its surface magnetic field and spindown, and there is no estimate for its mass and…
I describe a novel dark matter candidate in which the dark matter is composed of macroscopically large "nuggets" of ordinary quarks and antiquarks in a colour-superconducting phase. The physical properties of these objects are described…
A field star serendipitously observed in a parallax program proved to have a proper motion of 562 mas/yr and a parallax of 82 +- 2 mas. The star is identified with 2MASS J07003664+3157266. A Keck LRIS spectrum shows its spectral type to be…