The energetics, spectrum, and composition of cosmic rays with energies below ∼ 10 eV are fairly well explained by models involving supernova shocks. In contrast, no widely accepted theory exists for the origin of ultra-high energy cosmic rays (UHECRS), which have energies above 10 eV. Instead of proposing a specific model, here we place strong constraints on any model of UHECRS involving isolat...

Context. The possibility of observationally discriminating between various types of neutron stars, described by different equations of state of the nuclear matter, as well as differentiating neutron stars from other types of exotic objects, like, for example, quark stars, is one of the fundamental problems in contemporary astrophysics. Aims. We consider and investigate carefully the possibility...

We present the second in a series of results in which we have searched for undiscovered neutron stars in supernova remnants (SNRs). This paper deals with the largest six SNRs in our sample, too large for Chandra or XMM-Newton to cover in a single pointing. These SNRs are nearby, with typical distances of < 1 kpc. We therefore used the ROSAT Bright Source Catalog and past observations in the lit...

Theoretical models of the equation of state (EOS) of neutronstar matter (starting with the crust and ending at the densest region of the stellar core) are reviewed. Apart from a broad set of baryonic EOSs, strange quark matter, and even more exotic (abnormal and Q-matter) EOSs are considered. Results of calculations of Mmax for non-rotating neutron stars and exotic compact stars are reviewed, w...

We compute and present the distribution in mass of single and binary neutron stars, strange stars, and black holes. The calculations were performed using a stellar population synthesis code. We follow all phases of single and binary evolution, starting from a ZAMS binary and ending in the creation of one compact object (neutron star, black hole, strange star) and a white dwarf, or two compact o...

In this review we examine the dynamics and gravitational wave detectability of rotating strained neutron stars. The discussion is divided into two halves: triaxial stars, and precessing stars. We summarise recent work on how crustal strains and magnetic fields can sustain triaxiality, and suggest that Magnus forces connected with pinned superfluid vortices might contribute to deformation also. ...