2,540 research outputs found
R. Meynet, L. Pouzet, N. Farouki, A. Sinno, Rhétorique sémitique. Textes de la Bible et de la tradition musulmane, Paris, Cerf, 1998 (Patrimoines)
No full textHeintz Jean-Georges. R. Meynet, L. Pouzet, N. Farouki, A. Sinno, Rhétorique sémitique. Textes de la Bible et de la tradition musulmane, Paris, Cerf, 1998 (Patrimoines). In: Revue d'histoire et de philosophie religieuses, 81e année n°2, Avril-juin 2001. pp. 204-205
R. Meynet, L. Pouzet, N. Farouki, A. Sinno, Rhétorique sémitique. Textes de la Bible et de la tradition musulmane, Paris, Cerf, 1998 (Patrimoines)
No full textHeintz Jean-Georges. R. Meynet, L. Pouzet, N. Farouki, A. Sinno, Rhétorique sémitique. Textes de la Bible et de la tradition musulmane, Paris, Cerf, 1998 (Patrimoines). In: Revue d'histoire et de philosophie religieuses, 81e année n°2, Avril-juin 2001. pp. 204-205
The nature of the First Stars: the role of the isotopic ratios of barium
No full textIn the last years our group has found that many chemical anomalies
observed in very metal-poor halo stars suggest the First Stars were fast
rotators (spinstars). Recently, theoretical computations have found that
spinstars can also play a role in the chemical enrichment of neutron
capture elements providing a early contribution of s-process. By means
of a stochastic chemical evolution model, it is possible to identify the
spinstars s-process contribution as the missing component responsible
for the spread in the ratio between light (Sr) to heavy (Ba) neutron
capture elements. A specific distribution is predicted for the isotopic
ratio of Ba in halo stars and this imprint can be the smoking gun of the
existence of spinstars in the Early Universe
Existe una ética médica en Georges Canguilhem
No full textDespite recent efforts, little research has been done concerning the issue of medical ethics in Georges Canguilhem’s work. This is mainly due to the critical position the author takes regarding the humanistic medicine practices that began to [email protected]
Existe una ética médica en Georges Canguilhem
No full textDespite recent efforts, little research has been done concerning the issue of medical ethics in Georges Canguilhem’s work. This is mainly due to the critical position the author takes regarding the humanistic medicine practices that began to [email protected]
Letter from the Board of Directors of
No full text1. New A&A memberships and scientific editorial structure for the Letters section At its meeting in Tartu, Estonia on 8 May 2004, the A&A Board of
Directors decided to grant observer status on the Board to Brazil,
Chile, and Portugal (Sandqvist 2004, A&A, 426, E15). Then on 6–7
May 2005, at its meeting in La Laguna, Spain, the Board of Directors
admitted these three countries to full membership in A&A, starting
1 January 2006.
The Letters Editor, Dr. P. Schneider, will complete his terms of
service on 31 January 2006. A&A is indebted to him for his
thoughtful and competent editing over the past several years. As a
consequence of his departure, the Board has decided to restructure
the manner in which the Letters will be handled as of 1 January
2006. The Associate Editor-in-Chief, Dr. M. Walmsley, will also
become Editor-in-Chief for the Letters, and he will forward the
Letters to the appropriate topical Associate Editor to organize the
reviewing process. Likewise, the Editor-in-Chief, Dr. C. Bertout,
will become the Associate Letters-Editor-in-Chief. This change will
permit a more specialized treatment of Letters in the future and
also allow Letters to benefit from language editing. Hence, after 1
January 2006, manuscripts for Letters should be submitted via the
A&A Manuscript Management System (MMS) that is already in place for
Main Journal submissions. Letters submitted before that will be
handled by the current Letters Editor even after 1 January 2006. 2. New Associate Editor positions Considering both the increased workload on the Associate Editors due
to the above change and the continuing specialization of sub-fields
in astronomy, the Board decided to open two new positions for
Associate Editors, one specialized in Cosmology with a
particular interest in theoretical aspects and the other in
Observational Stellar Physics.
Applications are invited for these two new positions. The Associate
Editors are expected to have a broad knowledge of astronomy and
astrophysics and to have expertise in one of these two sub-fields.
Candidates should have a strong record of published research in
astronomy and astrophysics, should have experience as a referee
and/or journal editor, and be prepared to commit the time needed to
oversee the peer review of up to three hundred papers per year.
Limited support for office equipment and secretarial help, as well
as an annual indemnity, will be provided to the Associate Editors,
and the initial term of appointment is three years.
Applicants should submit a curriculum vitae, a list of publications,
and a concise covering letter that summarizes the candidate's
qualifications and the reasons for seeking an Associate Editor
position. The likelihood of support from the home institute for the
task should also be discussed in the application. Applications
should preferably be e-mailed or sent/faxed to the Chairman of the
Board of Directors:
Dr. Georges Meynet, Geneva Observatory, 1290 Sauverny, Switzerland, email [email protected]
Synthesis of 19F in Wolf-Rayet stars
No full textMeynet & Arnould (1993) have suggested that Wolf-Rayet (WR) stars could significantly contaminate the Galaxy with 19F. In their scenario, 19F is synthesized at the beginning of the He-burning phase from the 14N left over by the previous CNO-burning core, and is ejected in the interstellar medium when the star enters its WC phase. Recourse to CNO seeds makes the 19F yields metallicity-dependent. These yields are calculated on grounds of detailed stellar evolutionary sequences for an extended range of initial masses (from 25 to 120 M⊙) and metallicities (Z = 0.008, 0.02 and 0.04). The adopted mass loss rate prescription enables to account for the observed variations of WR populations in different environments. The 19F abundance in the WR winds of 60 M⊙ model stars is found to be about 10 to 70 times higher than its initial value, depending on the metallicity. This prediction is used in conjunction with a very simple model for the chemical evolution of the Galaxy to predict that WR stars could be significant (dominant?) contributors to the solar system fluorine content. We also briefly discuss the implications of our model on the possible detection of fluorine at high redshift.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
The thermonuclear production of19F by Wolf-Rayet stars revisited
No full textNew models of rotating and non-rotating stars are computed for initial masses between 25 and 120 M⊙ and for metallicities Z = 0.004, 0.008, 0.020, and 0.040 with the aim of reexamining the wind contribution of Wolf-Rayet (WR) stars to the 19F enrichment of the interstellar medium. Models with an initial rotation velocity vi = 300 km s -1 are found to globally eject less 19F than the non-rotating models. We compare our new predictions with those of Meynet & Arnould (2000, A&A, 355, 176), and demonstrate that the 19F yields are very sensitive to the still uncertain 19F(α, p) 22Ne rate and to the adopted mass loss rates. Using the recommended mass loss rate values that take into account the clumping of the WR wind and the NACRE reaction rates, when available, we obtain WR 19F yields that are significantly lower than predicted by Meynet & Arnould (2000, A&A, 355, 176) and that would make WR stars non-important contributors to the galactic 19F budget. In view, however, of the large nuclear and mass loss rate uncertainties, we consider that the question of the WR contribution to the galactic 19F remains quite open. © ESO 2005.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
About this researcher blog on Georges Focus
No full textGeorges Focus, who died in 1708, was a French painter who became crazy at the end of his life. He is the author of a bit more than 130 drawings, accompanied by poems, of great technical quality, made while suffering from psychological disorders. These bizarre works are also marked by great erudition and many precise allusions to contemporary personalities and events. They are a source of micro-history for research on 17th century French society, literature and fine arts. Public domain, htt..
New eyes on the first stars: the old bulge component and the important role of PNe in this context
No full textMost of the current observational efforts in finding the chemical
imprints left by the first stars have focused on the most metal-poor
(and probably oldest) stars found in the MW halo. Very metal-poor stars
were also found in ultra-faint dwarf galaxies, which are intriguing
dark-matter dominated objects with very low average metallicities.
Studies based on the chemical and kinematic properties of stars in the
different MW components have shown that not only the halo, but also the
bulge is a potential host of some of the oldest stars in our Galaxy. The
oldest Globular Cluster of the MW is located in the Bulge (Barbuy et al.
2009), and recently it has been possible to measure ages for microlensed
dwarf stars in the Bulge, finding very old objects. These both
observational results show that the oldest objects in the Bulge have
metallicities around [Fe/H] = -1, hence offering a new window on the
First Stars (Chiappini et al. 2011). Indeed, the correspondence between
age and metallicity is strongly dependent on the star formation history
of the particular studied component, and this suggestion has far
reaching implications.What I would like to show in my talk is the
importance Planetary Nebulae can play in this hot field. I will show
that by studying the PNe metallicity bulge distribution one can
highlight the "old Bulge" component. Once this important observational
constraint is used to guide chemical evolution models of the oldest
bulge population, one can use these models to look for imprints of the
first stars in the bulge. A comparison with what we have found so far
for the halo, and the new insights we can get by adding the Galactic
Bulge in this interesting topic will be shown and discussed
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