Related papers: Hard Burst Emission from the Soft Gamma Repeater S…
We study the temporal and coarse spectral properties of 268 bursts from SGR 1806-20 and 679 bursts from SGR 1900+14, all observed with the Rossi X-Ray Timing Explorer/Proportional Counter Array. Hardness ratios and temporal parameters, such…
We present evidence of a 6.4 keV emission line during a burst from the soft gamma-ray repeater SGR 1900+14. The Rossi X-ray Timing Explorer (RXTE) monitored this source extensively during its outburst in the summer of 1998. A strong burst…
Soft Gamma Repeaters (SGRs) undergo changes in their pulse properties and persistent emission during episodes of intense burst activity. SGR 1900+14 has undergone large flux increases following recent burst activity. Both SGR 1900+14 and…
We consider the evidence for very hard low energy spectra during the prompt phase of Gamma-Ray Bursts (GRB). In particular we examine the spectral evolution of GRB 980306 together with the detailed analysis of some other bursts already…
The low energy (<10 keV) X-ray emission of the Soft Gamma-ray Repeater SGR1806-20 has been studied by means of four XMM-Newton observations carried out in the last two years, the latter performed in response to a strong sequence of hard…
We present results on the Soft Gamma Repeater (SGR) 0501+4516, discovered by the SWIFT Burst Alert Telescope (BAT) on 2008 August 22. More than 50 bursts were identified from this source, out of which 18 bursts had enough counts to carry…
The Soft Gamma Repeater SGR 1900+14 entered a remarkable phase of activity during the summer of 1998. This activity peaked on August 27, 1998 when a giant periodic gamma-ray flare resembling the famous March 5, 1979 event from SGR 0526-66…
Soft Gamma Repeaters (SGRs) are a class of rare, high-energy galactic transients that have episodes of short (~0.1 sec), soft (~30 keV), intense (~100 Crab), gamma-ray bursts. We report an analysis of the x-ray emission from 95 SGR1806-20…
The extended high-energy gamma-ray (>100 MeV) emission occurring after the prompt gamma-ray bursts (GRBs) is usually characterized by a single power-law spectrum, which has been explained as the afterglow synchrotron radiation. We report on…
Soft Gamma Repeaters (SGRs) undergo changes in their pulse properties and persistent emission during episodes of intense burst activity. Both SGR 1900+14 and SGR 1806-20 have shown significant changes in their spin-down rates during the…
The prompt emission of the gamma-ray bursts is found to be very energetic, releasing ~10^51 ergs in a flash. However, their emission mechanism remains unclear and understanding their spectra is a key to determining the emission mechanism.…
A ~50 ks XMM-Newton observation of SGR 1900+14 has been carried out in September 2005, after almost three years during which no bursts were detected from this soft gamma-ray repeater. The 0.8-10 keV spectrum was well fit by a power law plus…
Soft gamma-ray repeaters (SGR) are a class of high energy transients whose brief emissions are thought to arise from young and highly magnetized neutron stars. The exact cause for these outbursts and the nature of the energy loss remain…
We consider the evidence for very hard low energy spectra during the prompt phase of Gamma Ray Bursts (GRB). In particular we examine the spectral evolution of GRB 980306 together with the detailed analysis of some other bursts already…
The high energy emission from Gamma-ray Bursts has some interesting features, including the absence of the GeV excess in the prompt spectrum, the delayed onset of the GeV emission, and the longer duration of the GeV emission than the prompt…
We present the results of a LIGO search for short-duration gravitational waves (GWs) associated with Soft Gamma Repeater (SGR) bursts. This is the first search sensitive to neutron star f-modes, usually considered the most efficient GW…
We present the results of a LIGO search for short-duration gravitational waves (GW) associated with soft gamma repeater (SGR) bursts. This is the first GW search sensitive to neutron star f-modes, usually considered the most efficient GW…
The Gamma Ray Burst (GRB) 180720B is one of the brightest events detected by the Fermi satellite and the first GRB detected by the H.E.S.S. telescope above 100 GeV. We analyse the Fermi (GBM and LAT) and Swift (XRT and BAT) data and…
In 2008 August, the new soft gamma-ray repeater SGR 0501+4516 was discovered by Swift. The source was soon confirmed by several groups in space- and ground-based multi-wavelength observations. In this letter we report the analysis of five…
Results are presented of the observations of the soft gamma repeater SGR 1900+14 made on the Wind spacecraft during the source reactivation period from May 1998 to January 1999. Individual characteristics of recurrent bursts, such as their…