Related papers: Diagnosing magnetars with transient cooling
The X-ray afterglow that is observed following large flares on magnetars can be accurately fit by simple and quantitative theoretical models: The long term afterglow, lasting of order weeks, can be understood as thermal radiation of a…
We explore the impact of a magnetar giant flare (GF) on the neutron star (NS) crust, and the associated baryon mass ejection. We consider that sudden magnetic energy dissipation creates a thin high-pressure shell above a portion of the NS…
We report the detection of large flux changes in the persistent X-ray flux of SGR 1900+14 during its burst active episode in 1998. Most notably, we find a factor ~700 increase in the non-burst X-ray flux following the August 27th flare,…
X-ray observations play a crucial role in understanding the emission mechanism and relevant physical phenomena of magnetars. We report X-ray observations of a young magnetar SGR 1900+14 made in 2016, which is famous for a giant flare in…
Transient outbursts from magnetars have shown to be a key property of their emission, and one of the main way to discover new sources of this class. From the discovery of the first transient event around 2003, we now count about a dozen of…
X-ray emission following giant flares of magnetars can be categorized into three categories of time scales (a) short term afterglow (b) medium term afterglow and (c) long term afterglow. Short term afterglow, which declines over several…
Young neutron stars born with magnetic fields $B\gtrsim 10^{16}$ G become hyperactive as the field inside the star evolves through ambipolar diffusion on a timescale $\sim 10^9$ s. We simulate this process numerically and find that it can…
Magnetars comprise two classes of rotating neutron stars (Soft Gamma Repeaters (SGRs) and Anomalous X-ray Pulsars), whose X-ray emission is powered by an ultrastrong magnetic field, B ~ 10^15 G. Occasionally SGRs enter into active episodes…
The multi-wavelength observations of the 2004 December~27 Giant Flare (GF) from SGR 1806-20 and its long-lived radio afterglow are briefly reviewed. The GF appears to have been produced by a dramatic reconfiguration of the magnetic field…
(ABBREVIATED) The extraordinary 1998 August 27 giant flare places strong constraints on the physical properties of its source, SGR 1900+14. We make detailed comparisons of the published data with the magnetar model. The giant flare evolved…
On December 27, 2004, a giant flare from SGR 1806$-$20 was detected on earth. Its thermal spectrum and temperature suggest that the flare resulted from an energy release of about $10^{47}$ erg/sec close to the surface of a neutron star in…
In the last few years it has been recognized that two apparently distinct classes of peculiar high-energy sources are actually related and can be explained as young neutron stars with magnetic fields as high as 10e14 - 10e15 Gauss. One of…
Over a decade ago it was established that the remarkable high energy transients, known as soft gamma-ray repeaters (SGRs), are a Galactic population and originate from neutron stars with intense (<~ 10^15 G) magnetic fields ("magnetars").…
Soft-gamma-ray repeaters (SGRs) are galactic X-ray stars that emit numerous short-duration (about 0.1 s) bursts of hard X-rays during sporadic active periods. They are thought to be magnetars: strongly magnetized neutron stars with…
We first review on the peculiar characteristics of the bursting and flaring activity of the Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars. We then report on the properties of the SGR 1806-20's Giant Flare occurred on 2004 December…
We study heat diffusion after an energy release in a deep spherical layer of the outer neutron star crust (10^7 < \rho < 4 x 10^{11} g/cm^3). We demonstrate that this layer possesses specific heat-accumulating properties, absorbing heat and…
We examine two trigger mechanisms, one internal and the other external to the neutron star, that give rise to the intense soft gamma-ray repeater (SGR) giant flares. So far, three giant flares have been observed from the three out of the…
Soft gamma repeaters (SGRs) are "magnetars", a small class of slowly spinning neutron stars with extreme surface magnetic fields, ~10^15 gauss. On 2004 December 27, a giant flare was detected from the magnetar SGR 1806-20, the third such…
Time-resolved spectra of six short gamma-ray bursts (sGRBs), measured by the {\em Swift} telescope, are used to estimate the parameters of a plerion-like model of the X-ray afterglow. The unshrouded, optically thin component of the…
We present one possible mechanism for the giant flares of the Soft Gamma-Ray Repeaters (SGRs) within the framework of magnetar, i.e., superstrongly magnetized neutron star model, motivated by the positive period increase associated with the…