Related papers: The missing compact star of SN1987A: a solid quark…
The surface of hot neutron stars is covered by a thin atmosphere. If there is accretion after neutron star formation, the atmosphere could be composed of light elements (H or He); if no accretion takes place or if thermonuclear reactions…
The central compact object (CCO) in the Vela Junior supernova remnant is a young neutron star whose relatively low X-ray flux and small distance suggest it has a mass high enough to activate fast neutrino cooling processes. Here we analyse…
The existence of quark matter inside the cores of heavy neutron stars is a possibility which can be probed with modern astrophysical observations. We use an (axial)vector meson extended quark-meson model to describe quark matter in the core…
P-stars are compact stars made of up and down quarks in beta-equilibrium with electrons in a chromomagnetic condensate. P-stars are able to account for compact stars like RXJ 1856.5-3754 and RXJ 0720.4-3125, stars with radius comparable…
We re-analysed numerous archival Chandra X-ray observations of the bright supernova remnant (SNR) 1E 0102.2-7219 in the Small Magellanic Cloud, to validate the detection of a neutron star (NS) in the SNR by Vogt et al. (2018). Careful…
Massive neutron stars may harbor deconfined quark matter in their cores. I review some recent work on the microphysics and the phenomenology of compact stars with cores made of quark matter. This includes the equilibrium and stability of…
We reexamine the surface composition of strange stars. Strange quark stars are hypothetical compact stars which could exist if strange quark matter was absolutely stable. It is widely accepted that they are characterized by an enormous…
Core collapse within blue supergiant stars, as occurred within Sk -69$^{\circ}$202/Supernova 1987A, is generally attributed to a merger of two electron-degenerate cores within a common envelope, with a merged mass in excess of 1.4 solar.…
The observation of neutrinos from Supernova~1987A has confirmed the theoretical conjecture that these particles play a crucial role during the collapse of the core of a massive star. Only one per cent of the energy they carry away from the…
It is still a matter of debate to understand the equation of state of cold supra-nuclear matter in compact stars because of unknown on-perturbative strong interaction between quarks. Nevertheless, it is speculated from an astrophysical view…
I review three problems in astrophysics of compacts stars: (i) the phase diagram of warm pair-correlated nuclear matter a sub-saturation densities at finite isospin asymmtery; (ii) the Standard Model neutrino emission from superfluid phases…
We present a quantitative analysis of superfluidity and superconductivity in dense matter from observations of isolated neutron stars in the context of the minimal cooling model. Our new approach produces the best fit neutron triplet…
After some historical remarks we discuss different criteria of dynamical stability of stars, and properties of the critical states where dynamical stability is lost, leading to collapse with formation of the neutron star or a black hole. At…
We report far-infrared and submillimeter observations of Supernova 1987A, the star that exploded on February 23, 1987 in the Large Magellanic Cloud, a galaxy located 160,000 lightyears away. The observations reveal the presence of a…
Recent Chandra observations have shown that the soft X-ray spectrum from the isolated neutron star RX J1856.5-3754 is featureless and best fitted by a blackbody, in contrast with the predictions of current neutron star atmospheric models.…
In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in…
Neutron stars are identified as pulsars, X-ray binary components, central objects of supernovae remnants, or isolated thermally emitting sources, and at distances beyond 120 pc. A population extrapolation suggests 10$^3$ objects within that…
A novel cooling mechanism is proposed for neutron stars, based on the recent development in the studies of the QCD phase diagram. Possible appearance of the inhomogeneous chiral phase makes the quark beta decay without gluonic interaction.…
Nearby dwarf irregular galaxies were searched for compact star clusters using data from the HST archives. Three of the galaxies were found to host both populous clusters (M_V<-9.5 at a fiducial age of 10 Myr) and super-star clusters…
We describe a population of compact objects in the centre of the Fornax Cluster which were discovered as part of our 2dF Fornax Spectroscopic Survey. These objects have spectra typical of old stellar systems, but are unresolved on…