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Magnetar
About: Magnetar is a research topic. Over the lifetime, 2905 publications have been published within this topic receiving 106806 citations.
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TL;DR: In this paper, the spectral and temporal results of the 40-700 keV observations, obtained with the Gamma-Ray Burst Monitor (GRBM) on board BeppoSAX, of the two large flares from the Soft Gamma-ray Repeater SGR 1900+14 occurred on August 27, 1998 and April 18, 2001.
Abstract: We report on spectral and temporal results of the 40-700 keV observations, obtained with the Gamma-Ray Burst Monitor (GRBM) on board BeppoSAX, of the two large flares from the Soft Gamma-ray Repeater SGR 1900+14 occurred on August 27, 1998 and April 18, 2001. From their intensity, fluence and duration, the first one was classified as "giant" and the second as "intermediate".The spectral results have been obtained with an improved response function of the GRBM. We find that the two events have similar spectral properties, but different temporal properties. The major difference concerns the time profiles of the light curves, whereas the lack of evidence in the 2001 flare for the erratic time variability found at high frequencies (10-1000 Hz) in the 1998 flare could be ascribed to lower counting statistics. We discuss these results in the light of the magnetar model proposed for SGR sources.
36 citations
TL;DR: In this paper, the electron-positron plasma generation processes in the magnetospheres of magnetars were considered and it was shown that the photon splitting in a magnetic field, which is effective at large field strengths, does not lead to suppression of plasma multiplication, but manifests itself in a high polarization of gamma-ray photons.
Abstract: We consider the electron-positron plasma generation processes in the magnetospheres of magnetars - neutron stars with strong surface magnetic fields, B = 10^(14) - 10^(15) G. We show that the photon splitting in a magnetic field, which is effective at large field strengths, does not lead to the suppression of plasma multiplication, but manifests itself in a high polarization of gamma-ray photons. A high magnetic field strength does not give rise to the second generation of particles produced by synchrotron photons. However, the density of the first-generation particles produced by curvature photons in the magnetospheres of magnetars can exceed the density of the same particles in the magnetospheres of ordinary radio pulsars. The plasma generation inefficiency can be attributed only to slow magnetar rotation, which causes the energy range of the produced particles to narrow. We have found a boundary in the P - Pdot diagram that defines the plasma generation threshold in a magnetar magnetosphere.
36 citations
TL;DR: In this paper, the authors reported the detection of a non-thermal X-ray burst in the 1-250 keV energy band with the Insight-HXMT satellite, which they identify as emitted from SGR J1935+2154.
Abstract: Fast radio bursts (FRBs) are short pulses observed in radio band from cosmological distances. One class of models invoke soft gamma-ray repeaters (SGRs), or magnetars, as the sources of FRBs. Some radio pulses have been observed from some magnetars, however, no FRB-like events had been detected in association any magnetar burst, including one giant flare. Recently, a pair of FRB-like bursts (FRB 200428 hereafter) separated by milliseconds (ms) were detected from the general direction of the Galactic magnetar SGR J1935+2154. Here we report the detection of a non-thermal X-ray burst in the 1-250 keV energy band with the Insight-HXMT satellite, which we identify as emitted from SGR J1935+2154. The burst showed two hard peaks with a separation of 34 ms, broadly consistent with that of the two bursts in FRB 200428. The delay time between the double radio and X-ray peaks is about 8.57 s, fully consistent with the dispersion delay of FRB 200428. We thus identify the non-thermal X-ray burst is associated with FRB 200428 whose high energy counterpart is the two hard peaks in X-ray. Our results suggest that the non-thermal X-ray burst and FRB 200428 share the same physical origin in an explosive event from SGR J1935+2154.
36 citations
INAF1
TL;DR: In this article, two classes of X-ray pulsars, the anomalous Xray Pulsars and the Soft Gamma-ray Repeaters, have been recognized as the most promising candidates for being magnetars: isolated neutron stars powered by magnetic energy.
Abstract: Two classes of X-ray pulsars, the Anomalous X-ray Pulsars and the Soft Gamma-ray Repeaters, have been recognized in the last decade as the most promising candidates for being magnetars: isolated neutron stars powered by magnetic energy. I review the observational properties of these objects, focussing on the most recent results, and their interpretation in the magnetar model. Alternative explanations, in particular those based on accretion from residual disks, are also considered. The possible relations between these sources and other classes of neutron stars and astrophysical objects are also discussed.
36 citations
TL;DR: In this paper, an analysis of archival X-ray observations of the Type IIL supernova SN 1979C is presented, and it is shown that its X-rays are remarkably constant at (6.5 ± 0.1) × 1038 − 1 s−1 over a period of 12 years between 1995 and 2007, which is consistent with either a supernova powered by magnetic braking of a rapidly rotating magnetar or a model where the blast wave is expanding into a dense circumstellar wind.
36 citations