Related papers: Magnetar giant flare high-energy emission
A model is developed for the time dependent electromagnetic - radio to gamma-ray - emission of active galactic nuclei, specifically, the blazars, based on the acceleration and creation of leptons at a propagating discontinuity or {\it…
We perform a multi-wavelength polarimetric study of the quasar CTA 102 during an extraordinarily bright $\gamma$-ray outburst detected by the {\it Fermi} Large Area Telescope in September-October 2012 when the source reached a flux of…
I. There is growing evidence that pulsars' high energy emission is generated via Inverse Compton mechanism. II. The particles producing Crab flares, and possibly most of the Crab Nebula's high energy emission, are accelerated via…
We analyse the damping by radiation reaction and by Compton drag of strong, superluminal electromagnetic waves in the context of pulsar winds. The associated radiation signature is found by estimating the efficiency and the characteristic…
Observations of gamma-ray bursts by the Fermi satellite, capable of detecting photons in a very broad energy band: 8keV to >300GeV, have opened a new window for the study of these enigmatic explosions. It is widely assumed that photons of…
Giant flares, short explosive events releasing up to 10$^{47}$ erg of energy in the gamma-ray band in less than one second, are the most spectacular manifestation of magnetars, young neutron stars powered by a very strong magnetic field,…
We propose a catastrophic magnetospheric model for magnetar precursors and their successive giant flares. Axisymmetric models of the magnetosphere, which contain both a helically twisted flux rope and a current sheet, are established based…
(abridged) Gamma-ray pulsars constitute a class of high and very high-energy emitters for which the known population is steadily increasing thanks to the Fermi/Large Area Telescope. In this paper, their gamma-ray luminosity and spectral…
We present the detections of 19 solar flares detected in high-energy gamma rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first four years of operation. Interestingly, all flares are associated with fairly fast…
This study focuses on high-redshift, z > 3, quasars where resolved X-ray jets remain underexplored in comparison to nearby sources. Building upon previous work, we identify and confirm extended kpc-scale jets emission in two quasars…
Observations of nearby star forming clouds with imaging X-ray telescopes have revealed that X-ray emission is elevated $10^1-10^4$ above main sequence levels in low-mass pre-main sequence (PMS) stars. The variability and spectral X-ray…
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…
Long-duration gamma-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterised by an initial phase of bright and highly variable radiation in the keV-MeV band…
A model is presented for the quasiperiodic component of magnetar emission during the tail phase of giant flares. The model invokes modulation of the particle number density in the magnetosphere. The magnetospheric currents are modulated by…
Solar flares are one of the main forces behind space weather events. However the mechanism that drives such energetic phenomena is not fully understood. The standard eruptive flare model predicts that magnetic reconnection occurs high in…
In December 2004, the soft gamma-ray repeater SGR 1806-20 emitted the most powerful giant flare ever observed. This probably involved a large-scale rearrangement of the magnetosphere leading to observable variations in the properties of its…
In this work, the straight flux rope in the model of giant flares on magnetars (Meng et al. 2014) was replaced with a curved one and the equilibrium behavior of the flux rope was investigated. Two footpoints of the flux rope are anchored to…
The emission mechanisms in extragalactic jets include synchrotron and various inverse-Compton processes. At low (radio through infrared) energies, it is widely agreed that synchrotron emission dominates in both low-power (FR I) and…
The high frequency component in blazars is thought to be due to inverse Compton scattered radiation. Recent observations by Fermi-LAT are used to evaluate the details of the scattering process. A comparison is made between the usually…
The process of energy release in the magnetosphere of a fast rotating, magnetized white dwarf can be explained in terms of the canonical spin-powered pulsar model. Applying this model to the white dwarf companion of the low mass close…