Gamma-Ray Bursts: Old and New

Gamma-ray bursts are the most luminous explosions in the Universe. They appear connected to supernova remnants from massive stars or the merger of their remnants, and their brightness makes them temporarily detectable out to the larges distances yet explored in the Universe. After pioneering breakthroughs from space and ground experiments, their study is entering a new phase with observations from recently launched satellites, as well as the prospect of detections or limits f...

In this paper we review the story of the BeppoSAX discovery of the Gamma Ray Burst afterglow and their cosmological distance, starting from their first detection with Vela satellites and from the efforts done before BeppoSAX. We also discuss the consequences of the BeppoSAX discovery, the issues left open by BeppoSAX, the progress done up to now and its perspectives.

Cosmic gamma-ray bursts are one of the great frontiers of astrophysics today. They are a playground of relativists and observers alike. They may teach us about the death of stars and the birth of black holes, the physics in extreme conditions, and help us probe star formation in the distant and obscured universe. In this review we summarise some of the remarkable progress in this field over the past few years. While the nature of the GRB progenitors is still unsettled, it now...

In the first part of this paper we summarize the discovery and the early study of the gamma-ray bursts. The second part studies the spatial and sky distribution of the bursters. The brightness distribution is also studied. In the conclusion we discuss that these are supporting the cosmological origin of the gamma-ray bursts.

The successful discovery of X-ray, optical and radio afterglows of gamma-ray bursts has significantly helped our understanding of these sources, and made possible the identification of host galaxies at cosmological distances. The energy release inferred rivals that of supernovae, while its photon energy output may considerably exceed it. Current models envisage this to be the outcome of a cataclysmic stellar event leading to a relativistically expanding fireball, in which par...

This is a review article for the book "Compact Stellar X-Ray Sources", Editors W. Lewin and M. van der Klis, to be published by Cambridge University Press in 2003. It covers the phenomenology of cosmic gamma-ray bursts, the theory of their afterglows, and the observations and interpretation of their host galaxies.

Decades of improving data and extensive theoretical research have led to a popular model of gamma-ray bursts. According to this model, a catastrophic event in a stellar system results in the formation of a compact central engine, which releases a fraction of a solar rest-mass energy within seconds in the form of ultra-relativistic jets. Dissipation of the jets energy leads first to prompt gamma-ray emission and later to a long lasting afterglow. Here I summarize the introduct...

The paper presents the nowdays definition of the phenomenon of cosmic gamma ray bursts, refers to the main alternative models of their origin and proposes three promising domains of new observations in the incoming decade.

Gamma Ray Bursts (GRBs) are unpredictable and brief flashes of gamma rays that occur about once a day in random locations in the sky. Since gamma rays do not penetrate the Earth's atmosphere, they are detected by satellites, which automatically trigger ground-based telescopes for follow-up observations at longer wavelengths. In this introduction to Gamma Ray Bursts we review how building a multi-wavelength picture of these events has revealed that they are the most energetic ...

The discoveries that GRBs have X-ray, optical and radio afterglows have connected the study of GRBs to the rest of astronomy, and revolutionized the field. In this review, I discuss the implications that the observation of these afterglows have for burst energies and luminosities, and for models of the bursts and their afterglows. I describe recent evidence linking the long, softer, smoother GRBs detected by BeppoSAX and core collapse supernovae. Finally, I summarize recent w...