Related papers: SGRs and AXPs as rotation powered massive white dw…

The key point of studying AXPs/SGRs (anomalous X-ray pulsars/soft gamma-ray repeaters) is relevant to the energy budget. Historically, rotation was thought to be the only free energy of pulsar until the discovery of accretion power in X-ray…

We consider the physical implications of the rapid spindown of Soft Gamma Repeater 1900+14, and of the apparent "braking glitch", \Delta P/P = l x 10^-4, that was concurrent with the Aug. 27th giant flare. A radiation-hydrodynamical outflow…

We consider applications of general relativistic uniformly-rotating white dwarfs to several astrophysical phenomena related to the spin-up and the spin-down epochs and to delayed type Ia supernova explosions of super-Chandrasekhar white…

The sources of ultra-high-energy cosmic rays ($E\gtrsim10^{19}$ eV) is still an open question in astroparticle physics and in the last years some efforts were made to understand its origin. In this work we consider white dwarf pulsars…

Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are magnetar candidates, i.e., neutron stars powered by strong magnetic field. If they are indeed magnetars, they will emit high-energy gamma-rays which are detectable by…

(ABBREVIATED) We consider the structure of neutron star magnetospheres threaded by large-scale electrical currents, and the effect of resonant Compton scattering by the charge carriers (both electrons and ions) on the emergent X-ray spectra…

Emission of two short hard X-ray bursts on 2009 June 5 disclosed the existence of a new soft gamma-ray repeater, now catalogued as SGR 0418+5729. After a few days, X-ray pulsations at a period of 9.1 s were discovered in its persistent…

Soft Gamma-ray Repeaters (SGRs) and Anomalous X-ray Pulsars (AXPs) are interpreted as young highly magnetized neutron stars (NSs). Their X-ray luminosity in quiescence, exceeding 10^{35} erg s^{-1} cannot be explained as due to cooling of a…

Assuming that AXPs and SGRs accrete matter from a fallback disk, we attempt to explain both the soft and the hard X-ray emission as the result of the accretion process. We also attempt to explain their radio emission or the lack of it. We…

Anomalous x-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are x-ray sources with unusual properties distinguishing them from both rotation-powered and most accretion-powered pulsars. Using archival ASCA data over the energy range…

We discuss some aspects of Sousa et al.(2020a, 2020b) concerning two mechanisms of gravitational wave (GW) emission in fast-spinning white dwarfs (WDs): accretion of matter and magnetic deformation. In both cases, the GW emission is…

Soft gamma-ray repeaters (SGRs) and Anomalous X-ray pulsars (AXPs) are generally accepted to be magnetars. Recently, Zhang, Xu & Qiao (2000, ApJ, 545, L127) proposed an alternative viewpoint about the nature of the SGRs (and AXPs). In this…

It is generally accepted that Anomalous X-ray Pulsars (AXPs) and Soft Gamma-ray Repeaters (SGRs) are magnetars, i.e. neutron stars with extremely high surface magnetic fields ($B > 10^{14}$ G). The origin of these high magnetic fields is…

Possible nature of strongly magnetized white dwarfs (SMWDs) is studied. It is shown that for relatively low values of the equatorial surface magnetic field $B\,\sim\,10^9\,-\,10^{11}$ G they can be good candidates for soft gamma-ray…

The observed upper bound on the spin down rate of the otherwise typical Soft Gamma-ray Repeater SGR 0418+5729 has challenged the interpretation of this source as a neutron star with ultrastrong magnetic fields. Current limits imply a dipole…

The similarity of rotation periods from three interesting classes of neutron stars, the anomalous X-ray pulsars (AXPs), the soft gamma ray repeaters (SGRs) and the dim isolated thermal neutron stars (DTNs) suggests a common mechanism with…

On 2009 June 5, the Gamma-ray Burst Monitor (GBM) onboard the Fermi Gamma-ray Space Telescope triggered on two short, and relatively dim bursts with spectral properties similar to Soft Gamma Repeater (SGR) bursts. Independent localizations…

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…

Anomalous X-ray Pulsars (AXPs) are a class of rare X-ray pulsars whose energy source has been perplexing for some 20 years. Unlike other, better understood X-ray pulsars, AXPs cannot be powered by rotation or by accretion from a binary…

More than two dozen soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) have been detected so far. These are isolated compact objects. Many of them are either found to be associated with supernova remnants or their surface…