The role of electron captures by nuclei in the shallow heating magnetars is further investigated using both nuclear measurements and theoretical atomic mass table HFB-27. Starting from composition outer crust full equilibrium, we have calculated onset heat released due to slow decay magnetic field. Numerical results are found be similar those previously obtained with HFB-24 model consistent neu...

The influence of exponential magnetic field decay (MFD) on the spin evolution of isolated neutron stars is studied. The ROSAT observations of several X-ray sources, which can be accreting old isolated neutron stars, are used to constrain the exponential and power-law decay parameters. We show that for the exponential decay the ranges of minimum value of magnetic moment, μb, and the characterist...

Anomalous X-ray pulsars (AXPs) are thought to be magnetars, which are neutron stars with ultra strong magnetic field of 1014–1015 G. Their energy spectra below ∼10 keV are modeled well by two components consisting of a blackbody (BB) (∼0.4 keV) and rather steep power-law (POW) function (photon index ∼2-4). Kuiper et al.(2004) discovered hard X-ray component above ∼10 keV from some AXPs. Here, w...

A great deal of evidence has recently been gathered in favor of the picture that Soft Gamma Repeaters and Anomalous X-Ray Pulsars are powered by ultra-strong magnetic fields (B> 1014 G; i.e. magnetars). Nevertheless, present determination of the magnetic field in such magnetar candidates has been indirect and model dependent. A key prediction concerning magnetars is the detection of ion cyclotr...

Gamma-ray bursts (GRBs) of long duration probably result from the core-collapse of massive stars in binary systems. After the collapse of the primary star the binary system may remain bound leaving a microquasar or ULX source as remnant. In this context, microquasars and ULXs are fossils of GRB sources and should contain physical and astrophysical clues on GRB-source progenitors. The identifica...

It is generally believed that magnetic fields of some neutron stars, the so-called magnetars, are enormously strong, up to 10–10 G. Recent investigations have shown that the atmospheres of magnetars are possibly composed of helium. We calculate the structure and bound-bound radiative transitions of the He ion in superstrong fields, including the effects caused by the coupling of the ion’s inter...