Astrophysics
We review the main sources of LiBeB production and show that a primary mechanism is at work in the early Galaxy involving both ejection and acceleration of He, C and O at moderate energy, which by nuclear interaction with H and He produce…
We update the Big Bang Nucleosynthesis (BBN) calculations on the basis of the recent NACRE compilation of reaction rates. In particular, we calculate the uncertainties related to the nuclear reaction rates on the abundances of 7Li and…
In this paper we present some results concerning the study of the development of galactic winds in blue compact galaxies. In particular, we model a situation very similar to that of the galaxy IZw18, the most metal poor and unevolved galaxy…
We adopt up-to-date 7Li yields from asymptotic giant branch stars in order to study the temporal evolution of this element in the solar neighbourhood. Several lithium stellar sources are considered besides the AGBs: Type II supernovae,…
The cosmological evolution of neutral hydrogen is an efficient way of tracing structure formation with redshift. It indicates the rate of evolution of gas into stars and hence the gas consumption and rate star formation history of the…
Preliminary results obtained with 320g bolometers with simultaneous ionization and heat measurements are described. After a few weeks of data taking, data accumulated with one of these detectors are beginning to exclude the upper part of…
The UV-X continuum, the X-ray spectral features, and the variability in these bands provide powerful tools for studying the innermost regions of AGNs from which we gain an insight into the accretion process. In this chapter the discussion…
SIMPLE (Superheated Instrument for Massive ParticLE searches) employs superheated droplet detectors (SDDs) to search for Weakly Interacting Massive Particle (WIMP) dark matter. As a result of the intrinsic SDD insensitivity to minimum…
This paper summarizes a project designed to study abundances in a sample of planetary nebulae representing a broad range in progenitor mass and metallicity. We collect abundances of C, N, and O determined for the entire sample and compare…
We have searched for axions which could have been produced in the solar core using an axion helioscope with a 2.3m-long 4T superconducting magnet. Axion mass region up to m_a=0.26eV was newly explored by introducing dispersion-matching gas.…
A new Solar System population of Weakly Interacting Massive Particle (WIMP) dark matter has been proposed to exist. We investigate the implications of this population on indirect signals in neutrino telescopes (due to WIMP annihilations in…
The question of the nature of the dark matter in the Universe remains one of the most outstanding unsolved problems in basic science. One of the best motivated particle physics candidates is the lightest supersymmetric particle, assumed to…
We have studied the effects on the gamma-ray flux on Earth by neutralino annihilations in caustic rings of dark matter in the Galactic halo. The caustic ring model by Sikivie has been used where dark matter particles are assumed to possess…
Clusters of galaxies are strong emitters of EUV and soft X-rays substantially in excess of the contribution from the hot intra-cluster medium at X-ray temperatures. After the initial discovery of EUV excess emission in the Virgo cluster,…
Some of the arguments which support the strong concensus for an $\Omega_o$ = 0.3, $\lambda_o$ = 0.7 model are reexamined. Corrections for Malmquist bias, local flow and metallicity suggest a revised value for $H_o$ of 63 $\pm$ 6 km/s/Mpc,…
A massive black hole is present at the centre of our galaxy and inevitably accretes dark matter particles, creating a region of very high particle density. The annihilation rate is enhanced with a large number of e+e- pairs produced either…
We generalize the spherical collapse model for the formation of dark matter halos to apply in a universe with arbitrary positive cosmological constant. We calculate the critical condition for collapse of an overdense region and give exact…
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for direct Dark Matter Search. The idea is to use superfluid He3 as a sensitive medium. The existing device, the superfluid He3 cell, will be briefly introduced. Then…
We investigate the possibility that ultra high energy cosmic rays (E > 10^19 eV) are related to the distribution of matter on large scales. The large scale structure (LSS) data stems from the recent IRAS PSCz redshift survey. We present…
Active Galactic Nuclei are fueled from material (gas or stars) that are in general far away from the gravitational influence of the central black hole, the engine thought to be responsible for their activity. The required material has a lot…