What SWIFT has taught us about X-ray flashes and long-duration gamma-ray bursts

Recent data gathered and triggered by the SWIFT satellite have greatly improved our knowledge of long-duration gamma ray bursts (GRBs) and X-ray flashes (XRFs). This is particularly the case for the X-ray data at all times, and for UV and optical data at very early times. I show that the optical and X-ray observations are in excellent agreement with the predictions of the "cannonball" model of GRBs and XRFs. Elementary physics and just two mechanisms underlie these predictions: inverse Compton scattering and synchrotron radiation, generally dominant at early and late times, respectively. I put this result in its proper context and dedicate the paper to those who planed, built and operate SWIFT, a true flying jewel.Comment: A talk at the 2007 Frascati Workshop, Vulcano, Italy. 12 pages total, 17 figure

GRBs in the Cannonball model: an overview

The cannonball model of GRBs is very overt (and, thus, falsifiable) in its hypothesis and results: all the considerations I review are based on explicit analytical expressions derived, in fair approximations, from first principles. The model provides a good description of all the data on all GRBs of known redshift, has made correct predictions, and is unprecedentedly self-consintent, simple and successful.Comment: 8 pages, 7 figures in text. To appear in the Proceedings of the 4th Microquasar Workshop, 2002, eds. Durouchoux, Fuchs & Rodriguez, published by the Center for Space Physics: Kolkata. Slightly longer versio

A Cannonball Model of Cosmic Rays

I outline a "Cannon-Ball" model of Cosmic Rays in which their distribution in the Galaxy, their total "luminosity", the broken power-law spectra with their observed slopes, the position of the knee(s) and ankle(s), and the alleged variations of composition with energy are all explained in terms of simple and "standard" physics.Comment: 10 pages, 7 figures. To appear in the proceedings of the XIII International Symposium on Very High Energy Cosmic Ray Interactions, Pylos, Greece, 200

The Cannonball Model of Gamma Ray Bursts: Lines in the X-Ray Afterglow

Recent observations suggest that gamma-ray bursts (GRBs) and their afterglows are produced by jets of highly relativistic cannonballs (CBs), emitted in supernova explosions. The fully ionized CBs cool to a temperature below 4500 K within a day or two, at which point electron-proton recombination produces an intense Lyman-$\alpha$ emission. The line energy is Doppler-shifted by the CBs' motion to X-ray energies in the observer's frame. The measured line energies, corrected for their cosmological redshift, imply Doppler factors in the range 600 to 1000, consistent with those estimated -in the CB model- from the characteristics of the $\gamma$-ray bursts. All other observed properties of the lines are also well described by the CB model. Scattering and self-absorption of the recombination lines within the CB also produce a wide-band flare-up in the GRB afterglow, as the observations indicate. A very specific prediction of the CB model is that the X-ray lines ought to be narrow and move towards lower line energies as they are observed: their current apparently large widths would be the effect of time integration, and/or of the blending of lines from CBs with different Doppler factors.Comment: 8 pages, no figure

The vicissitudes of "cannonballs": a response to criticisms by A.M. Hillas and a brief review of our claims

A.M. Hillas, in a review of the origins of cosmic rays, has recently criticized the "cannonball" (CB) model of cosmic rays and gamma-ray bursts. We respond to this critique and take the occasion to discuss the crucial question of particle acceleration in the CB model and in the generally accepted models. We also summarize our claims concerning the CB model.Comment: 3.3 pages, no figure

The time ending the shallow decay of the X-ray light curves of long GRBs

We show that the mean values and distributions of the time ending the shallow decay of the light curve of the X-ray afterglow of long gamma ray bursts (GRBs), the equivalent isotropic energy in the X-ray afterglow up to that time and the equivalent isotropic GRB energy, as well as the correlations between them, are precisely those predicted by the cannonball (CB) model of GRBs. Correlations between prompt and afterglow observables are important in that they test the overall consistency of a GRB model. In the CB model, the prompt and afterglow spectra, the endtime, the complex canonical shape of the X-ray afterglows and the correlations between GRB observables are not surprises, but predictions.Comment: 12 pages, 4 figure

On the origin of the diffuse gamma-ray background radiation

We show that inverse Compton scattering of cosmic-microwave-background and starlight photons by cosmic-ray electrons in the interstellar and intergalactic space explains well the spectrum and intensity of the diffuse gamma-ray background radiation (GBR), which was measured by EGRET aboard the Compton Gamma Ray Observatory (CGRO) in directions away from the Galactic disk and centre. The Gamma Ray Large Area Space Telescope (GLAST) will be able to separate the Galactic foreground from the extragalactic gamma-rays, and to provide stringent tests of the theory

An introduction to Cosmic Rays and Gamma-Ray Bursts, and to their simple understanding

I review the subjects of non-solar cosmic rays (CRs) and long-duration gamma-ray bursts (GRBs). Of the various interpretations of these phenomena, the one best supported by the data is the following. Accreting compact objects, such as black holes, are seen to emit relativistic puffs of plasma: `cannonballs' (CBs). The inner domain of a rotating star whose core has collapsed resembles such an accreting system. This suggests that core-collapse supernovae (SNe) emit CBs, as SN1987A did. The fate of a CB as it exits a SN and travels in space can be studied as a function of the CB's mass and energy, and of `ambient' properties: the encountered matter- and light- distributions, the composition of the former, and the location of intelligent observers. The latter may conclude that the interactions of CBs with ambient matter and light generate CRs and GRBs, all of whose properties can be described by this `CB model' with few parameters and simple physics. GRB data are still being taken in unscrutinized domains of energy and timing. They agree accurately with the model's predictions. CR data are centenary. Their precision will improve, but new striking predictions are unlikely. Yet, a one-free-parameter description of all CR data works very well. This is a bit as if one discovered QED today and only needed to fit $\alpha$.Comment: Contribution to La Thuile Workshop 2007. Brief chapter (13) added, prompted by recent Auger results on UHECR/AGN correlation