| 1. |
- Bagoly, Zsolt, et al.
(författare)
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Principal Component Analysis of Gamma-Ray Bursts' Spectra
- 2005
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Ingår i: Nuovo Cimento C. ; 28:3, s. 295-298
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Tidskriftsartikel (refereegranskat)abstract
- The origin of dark bursts--i.e. that have no observed afterglows in X-ray, optical/NIR and radio ranges--is unclear yet. Different possibilities--instrumental biases, very high redshifts, extinction in the host galaxies--are discussed and shown to be important. On the other hand, the dark bursts should not form a new subgroup of long gamma-ray bursts themselves.
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| 2. |
- Battistoni, G., et al.
(författare)
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The FLUKA code and its use in hadron therapy
- 2008
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Ingår i: Nuovo Cimento della Societa Italiana di Fisica C. - Italian Physical Society. - 1124-1896. ; 31:1, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- FLUKA is a multipurpose Monte Carto code describing transport and interaction with matter of a, large variety of particles over a wide energy range ill complex geometries. FLUKA is successfully applied ill several fields, including, but not only particle physics, cosmic-ray physics, dosimetry, radioprotection, hadron therapy. space radiation, accelerator design and neutronics. Here we briefly review recent model developments and provide examples of applications to hadron therapy, including calculation of physical and biological dose for comparison with analytical treatment planning engines as well as beta(+)-activation for therapy monitoring by means of positron emission tomography.
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| 3. |
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| 4. |
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| 5. |
- Meszaros, A., et al.
(författare)
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On the origin of the dark gamma-ray bursts
- 2005
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Ingår i: Nuovo cimento della societa italiana de fisica. C, Geophysics and space physics. - 1124-1896 .- 1826-9885. ; 28:3, s. 311-314
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Tidskriftsartikel (refereegranskat)abstract
- The origin of dark bursts-i.e. that have no observed afterglows in X-ray, optical/NIR and radio ranges-is unclear yet. Different possibilities-instrumental biases, very high redshifts, extinction in the host galaxies-are discussed and shown to be important. On the other hand, the dark bursts should not form a new subgroup of long gamma-ray bursts themselves.
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| 6. |
- Ryde, Felix, et al.
(författare)
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The conspicuous gamma-ray burst of 30 May 1996
- 2005
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Ingår i: Nuovo cimento della societa italiana de fisica. C, Geophysics and space physics. - 1124-1896 .- 1826-9885. ; 28:3, s. 335-338
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Tidskriftsartikel (refereegranskat)abstract
- The spectra of the majority of bursts exhibit a low-energy power law index, a, that is either a constant or becomes softer with time. However, in the burst of 30 May 1996 a becomes harder. Here we show that this behavior can be explained by a hybrid model consisting of a thermal and a non-thermal component. In this burst the power law index of the non-thermal component changes drastically from s similar to -1.5 to s similar to -0.67 at approximately 5 seconds after the trigger, thereby revealing, at low energies, the thermal component with its hard Rayleigh-Jeans tail. This leads to the large alpha-values that are found if the Band function is fitted to the spectra. We suggest that the change in s could be due to a transition from fast to slow cooling of the electrons emitting in the BATSE range. This could be due to the fact that the magnetic field strength becomes weaker.
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| 7. |
- Sparvoli, R., et al.
(författare)
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Cosmic rays studies with the PAMELA space experiment
- 2009
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Ingår i: Nuovo cimento della societa italiana de fisica. C, Geophysics and space physics. - 1124-1896 .- 1826-9885. ; 32:5-6, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- The instrument PAMELA, in orbit since June 15th, 2006 on board the Russian satellite Resurs DK1, is delivering to ground 16 Gigabytes of data per day. The apparatus is designed to study charged particles in the cosmic radiation, with a particular focus on antiparticles as a possible signature of dark matter annihilation in the galactic halo; the combination of a magnetic spectrometer and different detectors-indeed- allows antiparticles to be reliably identified from a large background of other charged particles. New results on the antiproton-to-proton and positron-to-all-electron ratios over a wide energy range (1-100GeV) have been recently released by the PAMELA Collaboration, and will be summarized in this paper. While the antiproton-to-proton ratio does not show particular differences from an antiparticle standard secondary production, in the positron-to-all-electron ratio an enhancement is clearly seen at energies above 10 GeV. Possible interpretations of this effect will be briefly discussed.
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