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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 article, the authors analyzed recent magnetar light-curve modeling of 38 hydrogen-poor superluminous supernovae (SLSNe) and found that the energies of the explosions themselves, that take place before the magnetar energy is released, are more than what the neutrino-driven explosion mechanism can supply for about half of the systems.
Abstract: We analyze recent magnetar light-curve modeling of 38 hydrogen-poor superluminous supernovae (SLSNe), and find that the energies of the explosions themselves, that take place before the magnetar energy is released, are more than what the neutrino-driven explosion mechanism can supply for about half of the systems. These SLSNe must have been exploded by a different process than the delayed neutrino mechanism, most likely the jet feedback mechanism (JFM). The conclusion for magnetar modeling of SLSNe is that jets launched at magnetar birth cannot be ignored, not at the explosion itself and not later when mass fall-back might occur. More generally, the present analysis strengthens the call for a paradigm shift from neutrino-driven to jet-driven explosion models of all core collapse supernovae.
44 citations
TL;DR: In this article, the authors proposed a new scenario in which fast radio bursts are powered by short-lived relativistic outflows from accreting black holes or neutron stars, which propagate into the cavity of the pre-existing (quiescent'') jet.
Abstract: The discovery of periodicity in the arrival times of the fast radio bursts (FRBs) poses a challenge to the oft-studied magnetar scenarios. However, models that postulate that FRBs result from magnetized shocks or magnetic reconnection in a relativistic outflow are not specific to magnetar engines; instead, they require only the impulsive injection of relativistic energy into a dense magnetized medium. Motivated thus, we outline a new scenario in which FRBs are powered by short-lived relativistic outflows (``flares'') from accreting black holes or neutron stars, which propagate into the cavity of the pre-existing (``quiescent'') jet. In order to reproduce FRB luminosities and rates, we are driven to consider binaries of stellar-mass compact objects undergoing super-Eddington mass-transfer, similar to ultraluminous X-ray (ULX) sources. Indeed, the host galaxies of FRBs, and their spatial offsets within their hosts, show broad similarities with ULXs. Periodicity on timescales of days to years could be attributed to precession (e.g., Lens-Thirring) of the polar accretion funnel, along which the FRB emission is geometrically and relativistically beamed, which sweeps across the observer line of sight. Accounting for the most luminous FRBs via accretion power may require a population of binaries undergoing brief-lived phases of unstable (dynamical-timescale) mass-transfer. This will lead to secular evolution in the properties of some repeating FRBs on timescales of months to years, followed by a transient optical/IR counterpart akin to a luminous red nova, or a more luminous accretion-powered optical/X-ray transient. We encourage targeted FRB searches of known ULX sources.
44 citations
TL;DR: In this article, a long-term study of the 2011 outburst of the magnetar Swift J1834.9•0846 carried out using new Chandra observations, as well as all the available Swift, RXTE, and XMMNewton data is presented.
Abstract: We present a long-term study of the 2011 outburst of the magnetar Swift J1834.9‐0846 carried out using new Chandra observations, as well as all the available Swift, RXTE, and XMMNewton data. The last observation was performed on 2011 November 12, about 100 days after the onset of the bursting activity that had led to the discove ry of the source on 2011 August 07. This long time span enabled us to refine the rotational eph emeris and observe a downturn in the decay of the X-ray flux. Assuming a broken power law for t he long-term light curve, the break was at �46 d after the outburst onset, when the decay index changed from α � 0.4 to �4.5. The flux decreased by a factor �2 in the first �50 d and then by a factor �40 until November 2011 (overall, by a factor �70 in �100 d). At the same time, the spectrum, which was well described by an absorbed blackbody all along the outburst, softened, the temperature dropping from �1 to �0.6 keV. Diffuse X-ray emission extending up to 20 ′′ from the source was clearly detected in all Chandraobservations. Its spatial and spectral properties, as well as its time evolution, are consistent with a dust-scattering h alo due to a single cloud located at a distance of �200 pc from Swift J1834.9‐0846, which should be in turn located at a distance of �5 kpc. Considering the time delay of the scattered photons, the same dust cloud might also be responsible for the more extended emission detected in XMM-Newtondata taken in September 2011. We searched for the radio signature of Swift J1834.9‐0846 at radio frequencies using the Green Bank Radio Telescope and in archival data collected at Parkes from 1998 to 2003. No evidence for radio emission was found, down to a flux densit y of 0.05 mJy (at 2 GHz) during the outburst and �0.2-0.3 mJy (at 1.4 GHz) in the older data.
44 citations
TL;DR: In this article, the X-ray spectra of a soft gamma-ray repeater SGR 0418+5729 were modeled to place constraints on the strength of the magnetic field at the surface of the source.
Abstract: 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 magnetic field strength of less than 7.5 x 10(12) G, which is significantly smaller than that of a typical SGR. Independent of the properties inferred from X-ray timing, the X-ray spectra of neutron stars allow a measurement of their magnetic field strengths because they are distorted from pure blackbodies due to the presence of a magnetic field in a radiative equilibrium atmosphere. In this paper, we model high signal-to-noise ratio XMMNewton spectra of SGR 0418+5729 to place constraints on the strength of the magnetic field at the surface of the neutron star. Our analysis shows that neutron star atmosphere models with moderate magnetic field strengths (10(12-13) G) cannot fit the X-ray spectra, whereas models with stronger magnetic fields are able to account for the observations. We find that the strength of the magnetic field at the surface is 1.0 x 10(14) G. This value, although lower than all of the other SGRs analysed to date, is still high enough to generate the observed X-ray bursts from the source. In connection to the spin-down limits, it also implies a significantly non-dipolar structure of the magnetic field. We discuss the results of our spectral modelling and compare them with other SGRs.
44 citations
21 Jan 2001
TL;DR: In this paper, it was shown that the merger of two CO white dwarfs produces both a Type Ia supernova explosion and a stellar remnant, the latter in the form of a magnetar.
Abstract: On the basis of the current observational evidence, we put forward the case that the merger of two CO white dwarfs produces both a Type Ia supernova explosion and a stellar remnant, the latter in the form of a magnetar. The estimated occurrence rates raise the possibility that many, if not most, SNe Ia might result from white dwarf mergers.
44 citations