相关论文: A magnetic white-dwarf accretion model for the ano…

It has been recently proposed that massive fast-rotating highly-magnetized white dwarfs could describe the observational properties of some of Soft Gamma-Ray Repeaters (SGRs) and Anomalous X-Ray Pulsars (AXPs). Moreover, it has also been…

The energy source of the anomalous X-ray pulsars is not well understood, hence their designation as anomalous. Unlike binary X-ray pulsars, no companions are seen, so the energy cannot be supplied by accretion of matter from a companion…

The phenomenology of anomalous X-ray pulsars is usually interpreted within the paradigm of very highly magnetized neutron stars, also known as magnetars. According to this paradigm, the persistent emission of anomalous X-ray pulsars (AXPs)…

Until 2004, Anomalous X-ray Pulsars (AXPs) were known as strong emitters of soft X-rays only (< 10 keV). The discovery of hard X-ray component from AXPs provided important insight about their emission properties while it posed a serious…

We propose that the quiescent emission of AXPs/SGRs is powered by accretion from a fallback disk, requiring magnetic dipole fields in the range 10^{12}-10^{13} G, and that the luminous hard tails of their X-ray spectra are produced by…

AXPs and SGRs constitute a special population of young neutron stars, which are thought to be magnetars, i.e., neutron stars with super-strong magnetic fields (10^14 - 10^15 G). Assuming that AXPs and SGRs accrete matter from a fallback…

The recent detection of the anomalous X-ray pulsar (AXP) 4U 0142+61 in the mid-infrared with the {\it Spitzer} observatory by Z.Wang and coworkers constitutes the first instance of a disk around an AXP. We show, by analyzing earlier optical…

We show that the observed pulsed optical emission of the anomalous X-ray pulsar 4U 0142+61 can be accounted for by both the magnetar outer gap models and the disk-star dynamo gap models, therefore is not an evidence in favor of one of these…

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…

Anomalous X-ray Pulsars (AXPs) are bright X-ray sources. Few AXPs emit highly pulsed emission in hard X-rays. Using data collected with the Large Area Telescope on board Fermi Gamma-ray Space Telescope, we explored high-energy gamma-ray…

The anomalous X-ray pulsar 4U 0142+61 was recently detected in the mid infrared bands with the SPITZER Observatory (Wang, Chakrabarty & Kaplan 2006). This observation is the first instance for a disk around an AXP. From a reanalysis of…

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…

After at least 6 years of quiescence, Anomalous X-ray Pulsar (AXP) 4U 0142+61 entered an active phase in 2006 March that lasted several months and included six X-ray bursts as well as many changes in the persistent X-ray emission. The…

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…

We explore the possibility that soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are powered by highly magnetized white dwarfs (B-WDs). We take a sample of SGRs and AXPs and provide the possible parameter space in mass,…

The anomalous X-ray pulsar 4U 0142+61 was studied by the INTEGRAL observations. The hard X-ray spectrum of 18 -- 500 keV for 4U 0142+61 was derived using near 9 years of INTEGRAL/IBIS data. We obtained the average hard X-ray spectrum of 4U…

We report on optical and infrared observations of the anomalous X-ray pulsar (AXP) 1E 1048.1-5937, made during its ongoing X-ray flare which started in 2007 March. We detected the source in the optical I and near-infrared Ks bands in two…

We present the first imaging circular polarimetry of the anomalous X-ray pulsar (AXP) 4U 0142+61 at optical wavelengths. The AXP is the only magnetar that has been well studied at optical and infrared wavelengths and is known to have 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…

We explore a possibility to explain the phenomenon of the Anomalous X-ray Pulsars (AXP) and Soft Gamma-ray Repeaters (SGR) within the scenario of fall-back magnetic accretion onto a young isolated neutron star. The X-ray emission of the…