相关论文: The Importance of Off-Axis Beaming in Jet Models
The gamma ray burst apparent average isotropic power versus their red-shift of all known GRB (Sept.2009) is reported. It calls for an unrealistic Gamma Ray Burst Evolution around us or it just probe the need of a very thin gamma…
Gamma ray bursts (GRB) occur at random points in the sky at cosmological distances. The spectra evolve through X-ray, optical region to possibly radio frequency. Though there are some models, the origin and time evolution of GRB are not…
Gamma-ray bursts (GRBs) are most intense transient gamma-ray events in the sky when they are on together with the strong evidences (i.e. the isotropic and inhomogeneous distribution of GRBs detected by BASTE) that they are located at…
Long duration gamma-ray bursts (GRB) are at cosmological distance, they appear to be located near star forming regions, and are likely associated with some type of supernovae. They are also likely to be strongly beamed, which lowers their…
GRBs have remained a puzzle for many high-energy astrophysicists since their discovery in 1967. With the advent of the X-ray satellites BeppoSAX and RossiXTE, it has been possible to carry out deep multi-wavelength observations of the…
Gravitationally lensed Gamma-ray bursts (GRBs) offer critical advantages over other lensed sources. They can be detected via continuously operating detectors covering most of the sky. They offer extremely high time resolution to determine…
If X-ray flashes (XRFs) and X-ray rich Gamma-ray Bursts(XRRGs) have the same origin with Gamma-ray Bursts (GRBs) but are viewed from larger angles of structured jets, their early afterglows may differ from those of GRBs. When the…
Growing observational evidence supports the proposition that gamma-ray bursts (GRBs) are powered by relativistic jets from massive helium stars whose cores have collapsed to black holes and an accretion disk (collapsars). We model the…
Gamma-ray bursts are known to be sources of high-energy gamma rays, and are likely to be sources of high-energy cosmic rays and neutrinos. Following a short review of observations of GRBs at multi-MeV energies and above, the physics of…
Long-duration gamma-ray bursts (GRBs) are widely believed to be highly-collimated explosions (opening angle theta ~ 1-10 deg). As a result of this beaming factor, the true energy release from a GRB is usually several orders of magnitude…
X-ray emission can provide a crucial diagnostic of gamma-ray bursts (GRBs). We calculate the X-ray and gamma-ray spectra of impulsive acceleration episodes related to GRB pulses. We use the synchrotron shock model (SSM) as a basis of our…
In many GRB inner engine models the highly relativistic GRB jets are engulfed by slower moving matter. This could result in different beaming for the prompt $\gamma$-ray emission and for the lower energy afterglow. In this case we should…
Extended, fading emissions in multi-wavelength are observed following Gamma-ray bursts (GRBs). Recent broad-band observational campaigns led by the Swift Observatory reveal rich features of these GRB afterglows. Here we review the latest…
Gamma-Ray Bursts (GRBs) are now considered as relativistic jets. We analyze the gravitational waves from the acceleration stage of the GRB jets. We show that (i) the point mass approximation is not appropriate if the opening half-angle of…
Typical observational gamma-ray burst (GRB) spectra are discussed and, in this connection, what is the origin of the compactness problem and how it was solved at first. If the threshold for $e^{-}e^{+}$ pair production depends on an angle…
Gamma-ray burst (GRB) engines are probed most intimately during the prompt gamma-ray luminous phase when the expanding blast wave is closest to the explosion center. Using GRBs 990123 and 940217 as guides, we briefly review observations of…
Correlations between optical flashes and gamma-ray emissions in gamma-ray bursts have been searched in order to clarify the question whether these emissions occur at internal and/or external shocks. Among the most powerful gamma-ray bursts…
The optical light that is generated simultaneously with the x-rays and gamma-rays during a gamma-ray burst (GRB) provides clues about the nature of the explosions that occur as massive stars collapse to form black holes. We report on the…
Gamma-ray bursts (GRB) are sudden, intense flashes of gamma-rays which, for a few blinding seconds, light up in an otherwise fairly dark gamma-ray sky. They are detected at the rate of about once a day, and while they are on, they outshine…
Gamma-ray Bursts (GRBs) are bursts of $\gamma$-rays generated from relativistic jets launched from catastrophic events such as massive star core collapse or binary compact star coalescence. Previous studies suggested that GRB emission is…