Abundances of neutron-capture elements in G 24-25. A halo-population CH subgiant

The differences between the neutron-capture element abundances of halo stars are important to our understanding of the nucleosynthesis of elements heavier than the iron group. We present a detailed abundance analysis of carbon and twelve neutron-capture elements from Sr up to Pb for a peculiar halo star G24-25 with [Fe/H] = -1.4 in order to probe its origin. The equivalent widths of unblended lines are measured from high resolution NOT/FIES spectra and used to derive abundances based on Kurucz model atmospheres. In the case of CH, Pr, Eu, Gd, and Pb lines, the abundances are derived by fitting synthetic profiles to the observed spectra. Abundance analyses are performed both relative to the Sun and to a normal halo star G16-20 that has similar stellar parameters as G24-25. We find that G24-25 is a halo subgiant star with an unseen component. It has large overabundances of carbon and heavy s-process elements and mild overabundances of Eu and light s-process elements. This abundance distribution is consistent with that of a typical CH giant. The abundance pattern can be explained by mass transfer from a former asymptotic giant branch component, which is now a white dwarf.Comment: 11 pages, 9 figures, accepted for publication in A&

HE1327-2326, an unevolved star with [Fe/H]<-5.0. I. A Comprehensive Abundance Analysis

We present the elemental abundances of HE1327-2326, the most iron-deficient star known, determined from a comprehensive analysis of spectra obtained with the Subaru Telescope High Dispersion Spectrograph.Comment: 53 pages, 14 figures, 10 tables, to appear in Ap

Are Proposed African Monetary Unions Optimal Currency Areas? Real and Monetary Policy Convergence Analysis

A spectre is hunting embryonic African monetary zones: the EMU crisis. The introduction of common currencies in West and East Africa is facing stiff challenges in the timing of monetary convergence, the imperative of bankers to apply common modeling and forecasting methods of monetary policy transmission, as well as the requirements of common structural and institutional characteristics among candidate states. Inspired by the premise of the EMU crisis, this paper assesses real and monetary policy convergence within the proposed WAM and EAM zones. In the analysis, monetary policy targets inflation and financial dynamics of depth, efficiency, activity and size while real sector policy targets economic performance in terms of GDP growth at macro and micro levels. Findings suggest overwhelming lack of convergence; an indication that candidate countries still have to work towards harmonizing cross-country differences in fundamental, structural and institutional characteristics that hamper the convergence process

Are Proposed African Monetary Unions Optimal Currency Areas? Real, Monetary and Fiscal Policy Convergence Analysis

Purpose – A spectre is hunting embryonic African monetary zones: the EMU crisis. This paper assesses real, monetary and fiscal policy convergence within the proposed WAM and EAM zones. The introduction of common currencies in West and East Africa is facing stiff challenges in the timing of monetary convergence, the imperative of central bankers to apply common modeling and forecasting methods of monetary policy transmission, as well as the requirements of common structural and institutional characteristics among candidate states. Design/methodology/approach – In the analysis: monetary policy targets inflation and financial dynamics of depth, efficiency, activity and size; real sector policy targets economic performance in terms of GDP growth at macro and micro levels; while, fiscal policy targets debt-to-GDP and deficit-to-GDP ratios. A dynamic panel GMM estimation with data from different non-overlapping intervals is employed. The implied rate of convergence and the time required to achieve full (100%) convergence are then computed from the estimations. Findings – Findings suggest overwhelming lack of convergence: (1) initial conditions for financial development are different across countries; (2) fundamental characteristics as common monetary policy initiatives and IMF backed financial reform programs are implemented differently across countries; (3) there is remarkable evidence of cross-country variations in structural characteristics of macroeconomic performance; (4) institutional cross-country differences could also be responsible for the deficiency in convergence within the potential monetary zones; (5) absence of fiscal policy convergence and no potential for eliminating idiosyncratic fiscal shocks due to business cycle incoherence. Practical implications – As a policy implication, heterogeneous structural and institutional characteristics across countries are giving rise to different levels and patterns of financial intermediary development. Thus, member states should work towards harmonizing cross-country differences in structural and institutional characteristics that hamper the effectiveness of convergence in monetary, real and fiscal policies. This could be done by stringently monitoring the implementation of existing common initiatives and/or the adoption of new reforms programs. Originality/value – It is one of the few attempts to investigate the issue of convergence within the proposed WAM and EAM unions

Carbon enhanced metal-poor stars I : Chemical compositions of 26 stars

Original article can be found at: http://www.iop.org/EJ/journal/apj Copyright American Astronomical Society. DOI: 10.1086/509817 [Full text of this article is not available in the UHRA]Peer reviewe