English
Related papers

Related papers: Scale-invariance in soft gamma repeaters

200 papers

On 2009 June 5, the Gamma-ray Burst Monitor (GBM) onboard the Fermi Gamma-ray Space Telescope triggered on two short, and relatively dim bursts with spectral properties similar to Soft Gamma Repeater (SGR) bursts. Independent localizations…

Emission of two short hard X-ray bursts on 2009 June 5 disclosed the existence of a new soft gamma-ray repeater, now catalogued as SGR 0418+5729. After a few days, X-ray pulsations at a period of 9.1 s were discovered in its persistent…

There are several phenomenological similarities between Soft Gamma Repeaters and Fast Radio Bursts, including duty factors, time scales and probable repetition. The sudden release of magnetic energy in a neutron star magnetosphere, as in…

High Energy Astrophysical Phenomena · Physics 2016-09-23 J. I. Katz

The spectra of soft gamma-ray repeaters (SGRs), with the exception of the March 5, 1979 main burst, are characterized by high-energy cutoffs around 30 keV and low-energy turnovers that are much steeper than a Wien spectrum. Baring (1995)…

Astrophysics · Physics 2009-10-28 Alice K. Harding , Matthew G. Baring

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…

Astrophysics · Physics 2009-10-22 E. E. Fenimore , J. G. Laros , A. Ulmer

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…

Astrophysics · Physics 2009-11-10 S. Mereghetti , A. Tiengo , P. Esposito , D. Gotz , L. Stella , G. L. Israel , N. Rea , M. Feroci , R. Turolla , S . Zane , -

We present results of variability study of a sample of 20 powerful blazars using Fermi/LAT (0.1--300 GeV) observations. We studied decade-long observations applying various analysis tools such as flux distribution, symmetry analysis, and…

High Energy Astrophysical Phenomena · Physics 2021-07-27 Gopal Bhatta , Niraj Dhital

Based on a 10 years sample of gamma-ray flares of FSRQs collected with FERMI and AGILE, I report on this proceeding the advance on a statistical study of variability for a sample of more than 300 FSRQs. I will focus on waiting time between…

High Energy Astrophysical Phenomena · Physics 2025-07-08 Luigi Pacciani

Gravitational wave bursters are sources which emit repeatedly bursts of gravitational waves, and have been recently suggested as potentially interesting candidates for gravitational wave (GW) detectors. Mechanisms that could give rise to a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Florian Dubath , Stefano Foffa , Maria Alice Gasparini , Michele Maggiore , Riccardo Sturani

We present an in-depth and systematic variability study of a sample of 20 powerful blazars, including 12 BL Lacs and 8 flat spectrum radio quasars, applying various analysis tools such as flux distribution, symmetry analysis, and time…

High Energy Astrophysical Phenomena · Physics 2020-03-18 Gopal Bhatta , Niraj Dhital

We investigate quantum persistence by analyzing amplitude and phase fluctuations of the wave function governed by the time-dependent free-particle Schr\"odinger equation. The quantum system is initialized with local random uncorrelated…

Statistical Mechanics · Physics 2025-05-09 Cheng Ma , Omar Malik , G. Korniss

The association of all three soft gamma-ray repeaters (SGRs) with supernova remnants has made possible estimates of the distance to and luminosity of the sources of SGRs, which have provided a starting point for detailed modeling. One of…

Astrophysics · Physics 2007-05-23 M. Coleman Miller , Tomasz Bulik

We present a 2 - 10 keV ASCA observation of the field around the soft gamma repeater SGR1900+14. One quiescent X-ray source was detected in this observation, and it was in the SGR error box. In 2 - 10 keV X-rays, its spectrum may be fit by…

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…

SGR 1627-41 was discovered in 1998 after a single active episode which lasted \~6 weeks. We report here our monitoring results of the decay trend of the persistent X-ray luminosity of the source during the last 5 years. We find an initial…

In 1998 May, the soft gamma repeater SGR1900+14 emerged from several years of quiescence and emitted a series of intense bursts, one with a time history unlike any previously observed from this source. Triangulation using Ulysses, BATSE,…

We investigate the rheological properties of an assembly of inelastic (but frictionless) particles close to the jamming density using numerical simulation, in which uniform steady states with a constant shear rate $\dot\gamma$ is realized.…

Soft Condensed Matter · Physics 2015-12-22 Takahiro Hatano

I summarize the recent advances in our understanding of the Soft Gamma Repeaters: in particular their spin behavior, persistent emission and hyper-Eddington outbursts. The giant flares on 5 March 1979 and 27 August 1998 provide compelling…

Astrophysics · Physics 2007-05-23 Christopher Thompson

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…

Astrophysics · Physics 2008-11-26 S. Mereghetti , P. Esposito , A. Tiengo , S. Zane , R. Turolla , L. Stella , G. L. Israel , D. Gotz , M. Feroci

The sky region containing the soft gamma-ray repeater SGR 1627-41 has been observed three times with XMM-Newton in February and September 2004. SGR 1627-41 has been detected with an absorbed flux of ~9x10^{-14} erg cm^{-2} s^{-1} (2-10…

Astrophysics · Physics 2009-11-11 S. Mereghetti , P. Esposito , A. Tiengo , R. Turolla , S. Zane , L. Stella , G. L. Israel , M. Feroci , A. Treves