Related papers: Fermi-GBM Team Analysis on The Ravasio Line
Recent observations of Gamma-Ray Bursts (GRBs) by the Fermi Large Area Telescope (LAT) revealed a power law decay feature of the high energy emission (above 100 MeV), which led to the suggestion that it originates from a (probably…
Gamma-ray bursts (GRBs) are the most energetic explosions in the universe, and their afterglow emission provides an opportunity to probe the physics of relativistic shock waves in an extreme environment. Several key pieces for completing…
We present multiwavelength observations of the afterglow of GRB 130427A, the brightest (in total fluence) gamma-ray burst of the past 29 years. Optical spectroscopy from Gemini-North reveals the redshift of the GRB to be z=0.340, indicating…
Gamma-ray bursts (GRBs) are the universe's most energetic phenomena (isotropic luminosity $\sim 10^{51} - 10^{54}$ ergs/s) lasting for a very short duration ($\sim$ milliseconds - a few seconds). Even after an average of one GRB detected…
Gamma-ray bursts are traditionally classified as short and long bursts based on their $T_{\rm 90}$ value (the time interval during which an instrument observes $5\%$ to $95\%$ of gamma-ray/hard X-ray fluence). However, $T_{\rm 90}$ is…
We present results of an analysis of a sample of bright Gamma-Ray Bursts (GRBs) detected by Fermi-GBM up to more than 1 MeV, which were collected during six years of Fermi operations. In particular, we focus on the GRB durations over…
GRB 190114C is the first gamma-ray burst detected at Very High Energies (VHE, i.e. >300 GeV) by the MAGIC Cherenkov telescope. The analysis of the emission detected by the Fermi satellite at lower energies, in the 10 keV -- 100 GeV energy…
The first gamma-ray burst (GRB) confirmed to be bright enough to be seen with the naked eye, GRB 080319B at redshift z = 0.937, allowed for exquisite follow-up observations across the electromagnetic spectrum. We present our detailed…
The brightest Gamma-ray burst, GRB 221009A, has spurred numerous theoretical investigations, with particular attention paid to the origins of ultra-high energy TeV photons during the prompt phase. However, analyzing the mechanism of…
Gamma-Ray Bursts (GRBs) are often referred to as the most luminous explosions in the Universe, due to their short and highly luminous prompt emission. This apparent luminosity, however, does not reflect the true energy budget of the prompt…
The brightest of all time (BOAT) GRB221009A show evidence for a narrow, evolving MeV emission line. Here, we show that this line can be explained as due to pair annihilation in the prompt emission region, and that its temporal evolution is…
Since its successful launch in June 2008, the {\it Fermi} Gamma-ray Space Telescope has made important breakthroughs in the understanding of the Gamma-Ray Burst (GRB) phenomemon. The combination of the GBM and the LAT instruments onboard…
At redshift z = 4.618, GRB 220101A is the most distant gamma-ray burst (GRB) detected by Fermi/LAT to date. It is also a very energetic event, with an equivalent isotropic energy of $3.6\times10^{54}$ erg. We jointly analyzed the Fermi/GBM…
The Fermi Gamma-ray Burst Monitor (GBM) is designed to enhance the scientific return from Fermi in studying gamma-ray bursts (GRBs). In its first two years of operation GBM triggered on 491 GRBs. We summarize the criteria used for…
The origin of gamma-ray burst (GRB) prompt emission, bursts of gamma-rays lasting from shorter than one second to thousands of seconds, remains not fully understood after more than 40 years of observations. The uncertainties lie in several…
Fast Radio Bursts (FRBs) are a mysterious flash phenomenon detected in radio wavelengths with a duration of only a few milliseconds, and they may also have prompt gamma-ray flashes. Here we carry out a blind search for msec-duration…
Gamma-ray bursts (GRBs) are bright flashes of gamma-rays coming from the cosmos. They occur roughly once per day, last typically 10s of seconds and are the most luminous events in the universe. More than three decades after their discovery,…
The prompt emission of gamma-ray bursts remains mysterious since the mechanism is difficult to understand even though there are much more observations with the development of detection technology. But most of the gamma-ray bursts spectra…
We compare the spectral properties of 227 Gamma Ray Bursts (GRBs) detected by the Fermi Gamma Ray Burst Monitor (GBM) up to February 2010 with those of bursts detected by the CGRO/BATSE instrument. Out of 227 Fermi GRBs, 166 have a measured…
The prompt emission of Gamma Ray Bursts (GRBs) is usually well described by the Band function: two power-laws joined smoothly at a given break energy. In addition to the Band component, a few bursts (GRB941017, GRB090510, GRB090902B and…