Maria A. Lugaro

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Asymptotic giant branch (AGB) stars are a main site of production of nuclei heavier than iron via the s process. In massive (>4 M ) AGB stars the operation of the Ne neutron source appears to be confirmed by observations of high Rb enhancements, while the lack of Tc in these stars rules out C as a main source of neutrons. The problem is that the Rb(More)
The recently improved information on the stellar (n, γ) cross sections of neutron-magic nuclei at N = 82, and in particular of Nd, turned out to represent a sensitive test for models of s-process nucleosynthesis. While these data were found to be incompatible with the classical approach based on an exponential distribution of neutron exposures, they provide(More)
Although mainstream SiC grains, the major group of presolar SiC grains found in meteorites, are believed to have originated in the expanding envelope of asymptotic giant branch (AGB) stars during their late carbon-rich phases, their Si isotopic ratios show a distribution that cannot be explained by nucleosynthesis in this kind of stars. Previously, this(More)
Among the short-lived radioactive nuclei inferred to be present in the early solar system via meteoritic analyses, there are several heavier than iron whose stellar origin has been poorly understood. In particular, the abundances inferred for (182)Hf (half-life = 8.9 million years) and (129)I (half-life = 15.7 million years) are in disagreement with each(More)
Context. Thermally pulsating asymptotic giant branch (AGB) stars are the main producers of slow neutron capture (s-) process elements, but there are still large uncertainties associated with the formation of the main neutron source, 13C, and with the physics of these stars in general. Observations of s-process element enhancements in stars can be used as(More)
Decompressive craniectomy (DC) is a surgical practice that has been used since the late 19th century. The cerebral blood flow increase after the performance of a DC can delay and even prevent the development of cerebral circulatory arrest and brain death (BD). We aimed to determine the prevalence of BD, the use of DC, and the evolution to BD with versus(More)
We present nucleosynthesis calculations and the resulting F stellar yields for a large set of models with different masses and metallicity. During the Asymptotic Giant Branch (AGB) phase F is produced as a consequence of nucleosynthesis occurring during the convective thermal pulses and also during the interpulse periods if protons from the envelope are(More)
Observations of planetary nebulae (PNe) by Sterling, Dinerstein and Bowers have revealed abundances in the neutron-capture element Germanium (Ge) from solar to factors of 3 – 10 above solar. The enhanced Ge is an indication that the slow-neutron capture process (s process) operated in the parent star during the thermallypulsing asymptotic giant branch(More)
The abundances of (92)Nb and (146)Sm in the early solar system are determined from meteoritic analysis, and their stellar production is attributed to the p process. We investigate if their origin from thermonuclear supernovae deriving from the explosion of white dwarfs with mass above the Chandrasekhar limit is in agreement with the abundance of (53)Mn,(More)
Aims. A super-solar fluorine abundance was observed in the carbon-enhanced metal-poor (CEMP) star HE 1305+0132 ([F/Fe] = +2.90, [Fe/H] = −2.5). We propose that this observation can be explained using a binary model that involve mass transfer from an asymptotic giant branch (AGB) star companion and, based on this model, we predict F abundances in CEMP stars(More)