Related papers: RX J1856.5-3754: A strange star with solid quark s…
Preliminary results of the RXTE observation of the Seyfert 2 Galaxy NGC4507 are presented. The observed broadband [4-100 keV] spectrum is intrinsically hard (Gamma = 1.2); an iron line is detected with a relatively high equivalent width (EW…
We present the discovery of a strongly phase-variable absorption feature in the X-ray spectrum of the nearby, thermally-emitting, isolated neutron star RX J0720.4-3125. The absorption line was detected performing detailed phase-resolved…
As a model for nonideal behavior in the equation of state of QCD at high density, we consider cold quark matter in perturbation theory. To second order in the strong coupling constant, $\alpha_s$, the results depend sensitively on the…
Red quasars may represent a young stage of galaxy evolution that provide important feedback to their host galaxies. We are studying a population of extremely red quasars (ERQs) with exceptionally fast and powerful outflows, at median…
We present the results of Chandra X-ray Observatory observations of the transient anomalous X-ray pulsar (AXP) candidate AX J1845.0-0258 in apparent quiescence. Within the source's error circle, we find a point source and possible…
Atmospheric studies of spectroscopically accessible terrestrial exoplanets lay the groundwork for comparative planetology between these worlds and the Solar System terrestrial planets. LHS 3844b is a highly-irradiated terrestrial exoplanet…
The interiors of high mass compact (neutron) stars may contain deconfined quark matter in a crystalline color superconducting (CCS) state. On a basis of microscopic nuclear and quark matter equations of states we explore the internal…
We consider propagation of heavy quarks in QCD matter. Because of large quark mass, the radiative quark energy loss appears to be qualitatively different from that of light quarks at all energies of practical importance. Finite quark mass…
It is shown that strange quark matter (SQM) objects, stars, and planets, can very efficiently convert the mechanical energy into hadronic energy when they oscillate. This is because the mass density at the edge of SQM objects,…
We investigate the thermodynamic properties of strange quark matter under the strong magnetic field in the framework of the MIT bag model in two cases of bag constants. We consider two cases of the magnetic field, the uniform magnetic field…
A type stars are expected to be X-ray dark, yet weak emission has been detected from several objects in this class. We present new Chandra/HRC-I observations of the A5 V star \beta{} Pictoris. It is clearly detected with a flux of 9+-2…
We report on the serendipitous X-ray detection, using the Chandra X-ray Observatory, of the radio pulsar J1718-3718. This pulsar has one of the highest inferred surface dipole magnetic fields in the radio pulsar population (B = 7.4e13 G),…
It was shown that pair luminosity of the newborn strange star with temperature of $10^{11}$ K may be as high as $L_\pm\simeq 10^{52}$ erg/s. The question remains: can a strange star maintain such a high surface temperature for a long time?…
A QCD analysis is reported of ATLAS data on inclusive W and Z boson production in pp collisions at the LHC, jointly with ep deep inelastic scattering data from HERA. The ATLAS data exhibit sensitivity to the light quark sea composition and…
We present spectroscopy and H alpha imaging of a faint nebula surrounding the X-ray bright, nearby neutron star RX J1856.5-3754. The nebula shows no strong lines other than the Hydrogen Balmer lines and has a cometary-like morphology, with…
We present the results of the analysis of the SRG/ART-XC observation of the Supergiant Fast X-ray Transient IGR J16195-4545 performed on March 3, 2021. Six bright flares are present in the light curve, with no significant change in hardness…
Compact stars made of quark matter rather than confined hadronic matter, are expected to form a color superconductor. This superconductor ought to be threaded with rotational vortex lines within which the star's interior magnetic field is…
Using the Color-Dielectric model to describe quark confinement, including strange quarks and accounting for beta--equilibrium, we get masses for a static neutron star in the range $1.3\leq M/M_{\odot}\leq 1.54 $ for a radius $R\approx 9$…
During 2003 and 2004 the Anomalous X-Ray Pulsar XTE J1810-197 went through a series of four bursts. The spectrum in the tail of one of these bursts shows a strong, significant emission feature ~13 keV, thereby encoding a wealth of…
Motivated by the observation of exotic structure around 6900MeV in the $J/\psi$-pair mass spectrum using proton-proton collision data by the LHCb collaboration, we study the spectra of fully-heavy tetraquarks within Bethe-Salpeter equation…