Related papers: An observational argument against accretion in mag…
The energy source powering the X-ray emission from anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) is still uncertain. In one scenario, the presence of an ultramagnetized neutron star, or ``magnetar'', with B on the order…
Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are enigmatic pulsar-like objects. The energy budget is the fundamental problem in their studies. In the magnetar model, they are supposed to be powered by the extremely…
PSRs J1847-0130 and J1718-37184 have inferred surface dipole magnetic fields greater than those of any other known pulsars and well above the ``quantum critical field'' above which some models predict radio emission should not occur.These…
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…
We examined the fall-back disk models, and in general accretion, proposed to explain the properties of anomalous X-ray pulsars (AXPs), soft gamma repeaters (SGRs), and radio pulsars (PSRs). We checked the possibility of some gas remaining…
I review of the observational properties of Soft Gamma Repeaters (SGRs) and Anomalous X-ray Pulsars (AXPs), two unusual manifestations of neutron stars. I summarize the reasoning for SGRs being "magnetars," neutron stars powered by the…
Possible manifestations of accreting magnetars are discussed. It is shown that the four ultra-luminous X-ray pulsars can be understood in the accreting low magnetic field magnetar scenario. The NGC300 ULX1 pulsar may have a higher dipole…
Anomalous X-ray Pulsars (AXPs) belong to a class of neutron stars believed to harbor the strongest magnetic fields in the universe, as indicated by their energetic bursts and their rapid spindowns. However, an unambiguous measurement of…
Anomalous X-ray Pulsars (AXPs) belong to a class of neutron stars believed to harbor the strongest magnetic fields in the universe, as indicated by their energetic bursts and their rapid spindowns. We have developed a theoretical model that…
We present results obtained from X-ray observations of the anomalous X-ray pulsar (AXP) 4U 0142+61 taken between 2000-2007 using XMM-Newton, Chandra and Swift. In observations taken before 2006, the pulse profile is observed to become more…
We present results of an observation of the anomalous X-ray pulsar 4U 0142+61 with the EPIC cameras on XMM-Newton performed on 2003 January 24. The pulse phase averaged spectrum can be best described by the sum of a black body with a…
Developments over the last couple of years have supported the interpretation that anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) possess unusually high magnetic fields, and furthermore may represent a class or classes of…
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…
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…
Soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are slowly rotating, isolated neutron stars that sporadically undergo episodes of long-term flux enhancement (outbursts) generally accompanied by the emission of short…
I will review the latest developments in understanding the high-energy emission of rotation-powered pulsars and magnetically-powered Anomalous X-ray Pulsars (AXPs) and Soft Gamma-Ray Repeaters (SGRs). These fields have been extremely active…
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…
We report on a 25 ks observation of the 8.7 s anomalous X-ray pulsar 4U~0142+61 with the High Energy Transmission Grating Spectrometer (HETGS) on the Chandra X-ray Observatory. The continuum spectrum is consistent with previous measurements…
The anomalous X-ray pulsars (AXPs) represent a growing class of neutron stars discovered at X-ray energies. While the nature of their multi-wavelength emission mechanism is still under debate, evidence has been recently accumulating in…
Anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) are two small classes of X-ray sources strongly suspected to host a magnetar, i.e. an ultra-magnetized neutron star with $B\approx 10^14-10^15 G. Many SGRs/AXPs are known to be…