We study the effects of magnetic field shear (By ≠ 0) and longitudinal propagation of perturbations (ky ≠ 0) on the linear and adiabatic magnetohydrodynamic (MHD) normal modes of oscillation of a potential coronal arcade. In a cold plasma, the inclusion of these two effects produces the linear coupling of discrete fast modes, characterised by a

The Chandra discovery of bright X-ray emission from kiloparsec-scale jets allows insight into the physical parameters of the jet flow at large scales. At the opposite extreme, extensive studies of the inner relativistic jets in blazars with multiwavelength observations yield comparable information on subparsec scales. In the framework of simple

We have performed a data analysis of the high-mass X- ray binary EXO 2030+375 using the three high-energy instruments on board INTEGRAL during a normal outburst of the source. The observations were made during the INTEGRAL Performance Verification phase in December 2002 and represent a total on-source time of about ¡£¢¥¤ s. X-ray pulsations with a

Millisecond radio pulsars are neutron stars that have been spun up by the transfer of angular momentum during the low-mass X-ray binary phase. The transition from an accretion-powered pulsar to a rotation-powered pulsar takes place on evolutionary timescales at the end of the accretion process; however, it may also occur sporadically in systems

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We find that the globular cluster (GC) systems of the Milky Way and of our neighboring spiral galaxy, M31, comprise two distinct entities, differing in three respects. First, M31 has a set of young GCs, ranging in age from a few times 102 Myr to 5 Gyr old, as well as old GCs. No such very young GCs are known in the Milky Way. Second, we confirm