Related papers: SMWDs as SGRs/AXPs and the lepton number violation
Many of the properties of anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are still a matter of much debate, as is the connection (if any) between these two groups of sources. In cases where we can identify the supernova…
This article is a review of Soft Gamma Repeaters and Anomalous X-ray Pulsars. It contains a brief historical record of the emergence of these classes of neutron stars, a thorough overview of the observational data, a succinct summary of the…
Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters have been generally recognized as neutron stars with super strong magnetic fields, namely "magnetars". The "magnetars" manifest that the luminosity in X-ray band are larger than the…
SGRs/AXPs are considered a subclass of pulsars powered by magnetic energy and not by rotation, as normal radio pulsars. They are understood as strongly magnetized neutron star, with large periods of rotation $P\sim(2-12)$ s, and large…
Anomalous X-ray Pulsars (AXPs) and Soft Gamma-Ray Repeaters (SGRs) are young neutron stars (NSs) characterized by high X-ray quiescent luminosities, outbursts, and, in the case of SGRs, sporadic giant flares. They are believed to be powered…
Soft gamma repeaters (SGR) are identified as single neutron stars (NS) inside the Galaxy, or nearby galaxies, with sporadic transient gamma radiation. A total number of discovered SGR, including relative Anomalous X-ray pulsars (AXP), is…
Soft gamma-ray repeaters (SGRs) and anomalous x-ray pulsars (AXPs) are young and radio-quiet x-ray pulsars which have been rapidly spun-down to slow spin periods clustered in the range 5-12 s. Most of these unusual pulsars also appear to be…
Soft gamma-ray repeaters (SGRs) and anomalous x-ray pulsars (AXPs) are young (<100 kyr), radio-quiet, x-ray pulsars which have been rapidly spun-down to slow spin periods clustered at 5-12 s. Nearly all of these unusual pulsars also appear…
A significant fraction of white dwarfs harbour a magnetic field with strengths ranging from a few kG up to about 1000 MG. The fraction appears to depend on the specific class of white dwarfs being investigated and may hold some clues to the…
The objects known as anomalous X-ray pulsars and soft gamma repeaters are commonly identified with magnetars, neutron stars with ultrastrong magnetic fields. The rotational history of these objects has, so far, revealed no evidence of free…
The magnetar model involves an isolated neutron star with a very high magnetic field (B~10^14-10^15 G), and is invoked to explain the emission processes of two classes of sources, the Anomalous X-ray Pulsars (AXPs) and the Soft Gamma-Ray…
Rotating magnetized white dwarfs are studied within the framework of general relativity using Hartle's formalism. Matter inside magnetized white dwarfs is described by an equation of state of particles under the action of a constant…
We address the physical nature of subdwarf A-type (sdA) stars and their possible link to extremely low mass (ELM) white dwarfs (WDs). The two classes of objects are confused in low-resolution spectroscopy. However, colors and proper motions…
The accretion of matter onto intermediate polar White Dwarfs (IPWDs) seems to provide attractive conditions for acceleration of particles to high energies in a strongly magnetized turbulent region at the accretion disk inner radius. We…
Strongly magnetized, rapidly rotating massive white dwarfs (WDs) emerge as potential outcomes of double degenerate mergers. These WDs can act as sources of non-thermal emission and cosmic rays, gethering attention as WD pulsars. In this…
White dwarf (WD) stars may radiate keV-energy axions produced in their stellar cores. This has been extensively studied as an extra channel by which WDs may cool, with some analyses even suggesting that axions can help explain the observed…
We make use of the high photometric precision of Kepler to search for periodic modulations among 14 normal (DA- and DB-type, likely non-magnetic) hot white dwarfs (WDs). In five, and possibly up to seven of the WDs, we detect periodic, ~2…
We have carried out a re-analysis of polarimetric data of central stars of planetary nebulae, hot subdwarfs, and white dwarfs taken with FORS1 (FOcal Reducer and low dispersion Spectrograph) on the VLT (Very Large Telescope), and added a…
Soft Gamma-ray Repeaters (SGRs) are among the most enigmatic sources known today. Exhibiting huge X- and Gamma-ray bursts and flares, as well as soft quiescent X-ray emission, their energy source remains a mystery. Just as mysterious are…
The concept of a "magnetar" was proposed mainly because of two factors. First, the X-ray luminosity of Anomalous X-ray Pulsars (AXPs) and Soft Gamma-Ray Repeaters (SGRs) is larger than the rotational energy loss rate, and second, the…