Pascal Chardonnet

On the Interpretation of the Burst Structure of Gamma-Ray Bursts

Given the very accurate data from the BATSE experiment and RXTE and Chandra satellites, we use the GRB 991216 as a prototypical case to test the EMBH theory linking the origin of the energy of GRBs to the electromagnetic energy of black holes. The fit of the afterglow fixes the only two free parameters of the model and leads to a new paradigm for the interpretation of the burst structure, the IBS paradigm. It leads as well to a reconsideration of the relative roles of the afterglow and burst in GRBs by defining two new phases in this complex phenomenon: a) the injector phase, giving rise to the proper-GRB (P-GRB), and b) the beam-target phase, giving rise to the extended afterglow peak emission (E-APE) and to the afterglow. Such differentiation leads to a natural possible explanation of the bimodal distribution of GRBs observed by BATSE. The agreement with the observational data in regions extending from the horizon of the EMBH all the way out to the distant observer confirms the uniqueness of the model. Subject headings: black holes, gamma ray bursts, supernovae The most decisive tool in the identification of the energetics of GRBs has been the discovery by Beppo SAX of the afterglow phenomenon. We show in this letter how the afterglow data can be fit using the theory which relates the GRB energy to the extraction process of the electromagnetic energy of a black hole endowed with electromagnetic structure (an EMBH). This energy extraction process occurs via vacuum polarization pair creation and approaches almost perfect reversibility in the sense of black hole physics (Christodoulou & Ruffini 1971; Damour & Ruffini 1975; Preparata et al. 1998). In addition to yielding excellent agreement between the theory and the data, a new paradigm will be introduced here for the interpretation of the burst structure which we call the IBS paradigm. ruffini@icra.it Because of the unique accuracy of its data, we use the GRB 991216 as a prototype for a description which may then be generalized to other GRBs. The relevant data for GRB 991216 are reproduced in Fig. 1, namely the data on the burst as recorded by BATSE (BATSE Rapid Burst Response 1999) and the data on the afterglow from the RXTE satellite (Corbet & Smith 2000) and the Chandra satellite (Piro et al. 2000) (see also Halpern et al. 2000). We have modeled the afterglow assuming that the ultra-high energy baryons (the ABM pulse of Ruffini et al. (2001a), Letter 1), accelerated in the pair-electromagneticbaryonic pulse (PEMB pulse) following a black hole collapse process (see Letter 1), after reaching transparency interact with the interstellar medium (ISM), assumed to have an average density nism of 1 proton/cm. All internal energy developed in the collision is assumed to be radiated away in a

On a Possible Gamma-Ray Burst-Supernova Time Sequence

The data from the Chandra satellite on the iron emission lines in the afterglow of GRB 991216 are used to give further support to the theory that links the origin of the energy of gamma-ray bursts (GRBs) to the extractable energy of electromagnetic black holes (EMBHs), leading to an interpretation of the GRB-supernova correlation. Following the relative spacetime transformation paradigm and the interpretation of the burst structure paradigm, we introduce a paradigm for the correlation between GRBs and supernovae. The following sequence of events is shown as kinematically possible and consistent with the available data: (1) the GRB-progenitor star P1 first collapses into an EMBH; (2) the proper GRB and the peak of the afterglow (the extended afterglow peak emission) propagate in interstellar space until the impact on a supernova-progenitor star P2 at a distance ≤2.69 × 1017 cm, and they induce the supernova explosion; and (3) the accelerated baryonic matter pulse, originating the afterglow, reaches the supernova remnants 18.5 hr after the supernova explosion and gives rise to the iron emission lines. Some considerations of the dynamical implementation of the paradigm are presented. The concept of an induced supernova explosion, introduced here specifically for the GRB-supernova correlation, may have a more general application in relativistic astrophysics.

Relative Spacetime Transformations in Gamma-Ray Bursts

GRB 991216 and its relevant data acquired from the BATSE and the Rossi X-Ray Timing Explorer and Chandra satellites are used as a prototypical case to test the theory linking the origin of gamma-ray bursts (GRBs) to the process of vacuum polarization occurring during the formation phase of a black hole endowed with electromagnetic structure. The relative spacetime transformation paradigm is presented. It relates the observed signals of GRBs to their past light cones, defining the events on the worldline of the source that is essential for the interpretation of the data. Since GRBs present regimes with unprecedentedly large Lorentz factors, and also sharply varying with time, particular attention is given to the constitutive equations relating the four time variables: the comoving time, the laboratory time, the arrival time, and the arrival time at the detector corrected by the cosmological effects. This paradigm is at the very foundation of any possible interpretation of the data of GRBs.

The production of anti-matter in our galaxy

Abstract The discovery of a single anti-helium nucleus in the cosmic ray flux would definitely point toward the existence of stars and even of entire galaxies made of anti-matter. The presence of anti-nuclei in cosmic rays has actually profound implications on the fundamental question of the baryon asymmetry of the universe. It is therefore crucial to determine the amount of anti-matter which our own galaxy already produces through the spallation of high-energy protons on the interstellar gas of the galactic disk. We have used here a coalescence model to assess the amount of anti-deuterium and anti-helium 3He present in cosmic rays together with anti-protons. The propagation of cosmic rays in the galaxy is described through a two-zone diffusion model which correctly describes the observed abundances. We find that the D p ratio exceeds 10−9 above a momentum per anti-nucleon of ∼ 4 GeV/c. Would the universe be purely made of matter, the AMS collaboration should be able to detect a few anti-deuterons during the space station stage of the experiment. However, the 3 He p abundance does not exceed ∼ 4 × 10−13. Heavier anti-nuclei are even further suppressed.

New perspectives in physics and astrophysics from the theoretical understanding of Gamma‐Ray Bursts

If due attention is given in formulating the basic equations for the Gamma‐Ray Burst (GRB) phenomenon and in performing the corresponding quantitative analysis, GRBs open a main avenue of inquiring on totally new physical and astrophysical regimes. This program is very likely one of the greatest computational efforts in physics and astrophysics and cannot be actuated using shortcuts. A systematic approach is needed which has been highlighted in three basic new paradigms: the relative space‐time transformation (RSTT) paradigm (Ruffini et al. [143]), the interpretation of the burst structure (IBS) paradigm (Ruffini et al. [144]), the GRB‐supernova time sequence (GSTS) paradigm (Ruffini et al. [145]). From the point of view of fundamental physics new regimes are explored: (1) the process of energy extraction from black holes; (2) the quantum and general relativistic effects of matter‐antimatter creation near the black hole horizon; (3) the physics of ultrarelativisitc shock waves with Lorentz gamma factor γ ...

Galactic diffusion and the antiproton signal of supersymmetric dark matter

Abstract The leaky box model is now ruled out by measurements of a cosmic ray gradient throughout the galactic disk. It needs to be replaced by a more refined treatment which takes into account the diffusion of cosmic rays in the magnetic fields of the Galaxy. We have estimated the flux of antiprotons on the Earth in the framework of a two-zone diffusion model. Those species are created by the spallation reactions of high-energy nuclei with the interstellar gas. Another potential source of antiprotons is the annihilation of supersymmetric particles in the dark halo that surrounds our Galaxy. In this letter, we investigate both processes. Special emphasis is given to the antiproton signature of supersymmetric dark matter. The corresponding signal exceeds the conventional spallation flux below 300 MeV, a domain that will be thoroughly explored by the Antimatter Spectrometer experiment. The propagation of the antiprotons produced in the remote regions of the halo back to the Earth plays a crucial role. Depending on the energy, the leaky box estimates are wrong by a factor varying from 0.5 up to 3.

The Observed Galactic Annihilation Line: Possible Signature of Accreting Small-Mass Black Holes in the Galactic Center

Various balloon and satellite observatories have revealed what appears to be an extended source of 0.511 MeV annihilation radiation with flux of approx. 10(exp -3) photons/sq cm/s centered on the Galactic Center. Positrons from radioactive products of stellar explosions can account for a significant fraction of the emission. We discuss an additional source for this emission: namely e(+)e(-) pairs produced when X-rays generated from the approx. 2.6 x 10(exp 6) solar mass Galactic Center Black Hole interact with approx. 10 MeV temperature blackbody emission from 10(exp 17) g black holes within 10(exp 14-l5) cm of the center. The number of such Small Mass Black Holes (SMMBHs) can account for the production of the 10(exp 42) e(+)/s that produces the observed annihilation in the inner Galaxy when transport effects are taken into account. We consider the possibility for confirming the presence of these SMMBHs in the Galactic Center region with future generations of gamma-ray instruments if a blackbody like emission of approx. 10 MeV temperature would be detected by them. Small Mass Black Hole can be a potential candidate for dark (invisible) matter halCompton Gamma Ray Observatory, OSSE, SMM, TGRS, balloon and recent INTEGRAL data reveal a feature of the 0.511 MeV annihilation radiation of the Galactic Center with a flux of approximately 5 × 10 −4 0.511 MeV photons cm −2 s −1. We argue that e + e − pairs can be generated when the X-ray radiation photons and ∼ 10 − 30 MeV photons interact with each other in the compact region in the proximity of the Galactic Center black hole. In fact, disks formed near black holes of 10 17 g mass should emit the ∼ 10 MeV temperature blackbody radiation. If positron (e +) sources are producing about 10 42 e + s −1 near the Galactic Center they would annihilate on the way out and result in 0.511 MeV emission. We suggest that the annihilation radiation can be an observational consequence of the interaction of the accretion disk radiation of the SMall Mass Black Holes (SMMBHs) with X-ray radiation in the Galactic Center. This is probably the only way to identify and observe these SMMBHs.

The Blackholic energy: long and short Gamma‐Ray Bursts (New perspectives in physics and astrophysics from the theoretical understanding of Gamma‐Ray Bursts, II)

We outline the confluence of three novel theoretical fields in our modeling of Gamma‐Ray Bursts (GRBs): 1) the ultrarelativistic regime of a shock front expanding with a Lorentz gamma factor ∼ 300; 2) the quantum vacuum polarization process leading to an electron‐positron plasma originating the shock front; and 3) the general relativistic process of energy extraction from a black hole originating the vacuum polarization process. There are two different classes of GRBs: the long GRBs and the short GRBs. We here address the issue of the long GRBs. The theoretical understanding of the long GRBs has led to the detailed description of their luminosities in fixed energy bands, of their spectral features and made also possible to probe the astrophysical scenario in which they originate. We are specially interested, in this report, to a subclass of long GRBs which appear to be accompanied by a supernova explosion. We are considering two specific examples: GRB980425/SN1998bw and GRB030329/SN2003dh. While these sup...

EMERGENCE OF A FILAMENTARY STRUCTURE IN THE FIREBALL FROM GRB SPECTRA

It is shown that the concept of a fireball with a definite filamentary structure naturally emerges from the analysis of the spectra of Gamma-Ray Bursts (GRBs). These results, made possible by the recently obtained analytic expressions of the equitemporal surfaces in the GRB afterglow, depend crucially on the single parameter ℛ describing the effective area of the fireball emitting the X-ray and gamma-ray radiation. The X-ray and gamma-ray components of the afterglow radiation are shown to have a thermal spectrum in the co-moving frame of the fireball and originate from a stable shock front described self-consistently by the Rankine–Hugoniot equations. Precise predictions are presented on a correlation between spectral changes and intensity variations in the prompt radiation verifiable, e.g., by the Swift and future missions. The highly variable optical and radio emission depends instead on the parameters of the surrounding medium. The GRB 991216 is used as a prototype for this model.

Black Hole Physics and Astrophysics: The GRB-Supernova Connection and URCA-1 - URCA-2

We outline the confluence of three novel theoretical fields in our modeling of Gamma-Ray Bursts (GRBs): 1) the ultrarelativistic regime of a shock front expanding with a Lorentz gamma factor