Related papers: LiBeB Production and Associated Astrophysical Site…
We update Standard Big Bang Nucleosynthesis (SBBN) calculations on the basis of recent nuclear physics compilations (NACRE in particular), experimental and theoretical works. By a Monte--Carlo technique, we calculate the uncertainties on…
Elemental abundances of carbon, nitrogen, oxygen, magnesium, aluminum, and silicon are presented for a sample of twelve rapidly rotating OB star (v sin i > 60 km s^-1) members of the Cep OB2, Cyg OB3 and Cyg OB7 associations. The abundances…
The standard model of primordial nucleosynthesis by the Big Bang as selected by the WMAP-based estimate of the baryon density ($\Omega_bh^2$) predicts an abundance of $^7$Li that is a factor of three greater than the generally reported…
We compute the evolution of different abundance ratios in the Milky Way (MW) for two different sets of stellar yields. In one of them stellar rotation is taken into account and we investigate its effects on the chemical evolution model…
We predict a strikingly different $A$ and $Q^{2}$ dependence of quasielastic leptoproduction of the $\rho^{0}(1S)$-meson and its radial excitation $\rho '(2S)$ on nuclei. Whereas for the $\rho^{0}$ production nuclear transparency $T_{A}$…
Recently, an anomalous generation of multiple plasmons with large spectral weight transfer in the visible to ultraviolet range (energies below the band gap) has been experimentally observed in the insulating-like phase of oxygen-rich…
The prejudice against baryon isocurvature models is primarily because of their inconsistency with early universe light element nucleosynthesis results. We propose that incipient low metallicity (Pop II) star forming regions can be expected…
Even though the main nucleosynthetic products of type Ia supernovae belong to the iron-group, intermediate-mass alpha-nuclei (silicon, sulfur, argon, and calcium) stand out in their spectra up to several weeks past maximum brightness.…
"The purpose of numerical models is not numbers but insight." (Hamming) In the spirit of this adage, and of Don Cox's approach to scientific speaking, we discuss the questions that the latest generation of numerical models of the…
Magnetic confinement of stellar winds leads to the formation of magnetospheres, which can be sculpted into Centrifugal Magnetospheres (CMs) by rotational support of the corotating plasma. The conditions required for the CMs of magnetic…
The 18O/17O ratio of the Solar System is 5.2 while that of the interstellar medium (ISM) and young stellar objects is ~4. This difference cannot be explained by pollution of the Sun's natal molecular cloud by 18O-rich supernova ejecta…
Measurable amounts of Be could have been synthesised primordially if the Universe were non-homogeneous or in the presence of late decaying relic particles. We investigate the Be abundance in the extremely metal-poor star 2MASS J1808-5104…
An overview of the sources for heavy elements in the early Galaxy is given. It is shown that observations of abundances in metal-poor stars can be used along with a basic understanding of stellar models to guide the search for the source of…
Oxygen and carbon-rich AGB stars - and objects directly polluted by them - are excellent laboratories to investigate the nucleosynthesis and mixing processes occurring during the later phases of the of low- and intermediate-mass star…
We suggest that if the astrophysical site for r-process nucleosynthesis in the early Galaxy is confined to a narrow mass range of Type II supernova (SN II) progenitors, with a lower mass limit of Mms = 20 Msun, a unique feature in the…
The non-local thermodynamic equilibrium (NLTE) line formation of neutral boron in the atmospheres of cool stars are investigated. Our results confirm that NLTE effects for the B I resonance lines, which are due to a combination of…
We infer mechanisms of galaxy formation for a broad family of semi-analytic models (SAMs) constrained by the K-band luminosity function and HI mass function of local galaxies using tools of Bayesian analysis. Even with a broad search in…
We show that the observed ratio of the subtypes Ib,c and II core-collapse supernovae depends on the metallicity of the host galaxy, as expected on theoretical grounds. However, the observed relation differs considerably from expectations…
Several years of neutral particle measurements by the NASA/IBEX mission have yielded direct observations of interstellar neutral helium and oxygen. The data indicate the presence of secondary neutral helium and oxygen, which are created…
The problem of the origin of nitrogen is considered within the framework of an empirical approach. The oxygen abundances and nitrogen to oxygen abundances ratios are derived in HII regions of a number of spiral galaxies through the recently…