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Related papers: Galactic Sodium from AGB Stars

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We present a new generation of chemically consistent evolutionary synthesis models for galaxies of various spectral types from E through Sd. The models follow the chemical enrichment of the ISM and take into account the increasing initial…

We present different chemical evolution models for the ultrafaint dwarf galaxy Bootes I. We either assume that the galaxy accretes its mass through smooth infall of gas of primordial chemical composition (classical models) or adopt mass…

Astrophysics of Galaxies · Physics 2015-06-23 Donatella Romano , Michele Bellazzini , Else Starkenburg , Ryan Leaman

We examine how the atomic and molecular gas components of galaxies evolve to higher redshifts using the semi-analytic galaxy formation models of Fu et al. (2010) in which we track the surface density profiles of gas in disks. We adopt two…

Astrophysics of Galaxies · Physics 2015-06-04 Jian Fu , Guinevere Kauffmann , Cheng Li , Qi Guo

Context: Stars evolving through the asymptotic giant branch (AGB) phase provide significant feedback to their host system, in form of both gas enriched in nuclear-burning products and dust formed in their winds, which they eject into the…

Solar and Stellar Astrophysics · Physics 2020-07-07 Paolo Ventura , Flavia Dell'Agli , Maria Lugaro , Donatella Romano , Marco Tailo , Andres Yague

The asymptotic giant branch (AGB) phase is the final stage of nuclear burning for low-mass stars. Although Milky Way globular clusters are now known to harbour (at least) two generations of stars they still provide relatively homogeneous…

We present stellar yields computed from detailed models of intermediate mass asymptotic giant branch stars of low metallicity. In this work, the whole main microphysics inputs have been updated, and in particular alpha-enhancement is…

Astrophysics · Physics 2009-11-13 Paolo Ventura , Francesca D'Antona

This paper investigates the peculiar behaviour of the light even (alpha-elements) and odd atomic number elements in red giants in the galactic bulge, both in terms of the chemical evolution of the bulge, and in terms of possible deep-mixing…

Astrophysics · Physics 2009-11-11 A. Lecureur , V. Hill , M. Zoccali , B. Barbuy , A. Gomez , D. Minniti , S. Ortolani , A. Renzini

We present new analytic solutions for one-zone (fully mixed) chemical evolution models and explore their implications. In contrast to existing analytic models, we incorporate a realistic delay time distribution for Type Ia supernovae (SNIa)…

Astrophysics of Galaxies · Physics 2017-03-22 David H. Weinberg , Brett H. Andrews , Jenna Freudenburg

Observations give evidences of the presence of metals in the intergalactic medium (IGM). The stars responsible for transforming hydrogen and helium into more complex atoms do not form outside the galaxies in the standard scenario of galaxy…

Astrophysics · Physics 2009-11-11 Yohan Dubois , Romain Teyssier

We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) database (Suda et al. 2008, PASJ, 60, 1159).The analyses of carbon-enhanced stars in our…

Astrophysics of Galaxies · Physics 2015-05-20 Takuma Suda , Shimako Yamada , Yutaka Katsuta , Yutaka Komiya , Chikako Ishizuka , Wako Aoki , Masayuki Y. Fujimoto

We have extended our analytical chemical evolution modelling ideas for the Galaxy to the Magellanic Clouds. Unlike previous authors, we assume neither a steepened IMF nor selective galactic winds, since among the alpha-particle elements…

Astrophysics · Physics 2009-07-28 B. E. J. Pagel , G. Tautvaisiene

Lithium abundances are presented for 91 dwarf and subgiant stars in the Galactic bulge. The analysis is based on line synthesis of the 7Li line at 6707 {\AA} in high-resolution spectra obtained during gravitational microlensing events, when…

Astrophysics of Galaxies · Physics 2020-02-26 T. Bensby , S. Feltzing , J. C. Yee , J. A. Johnson , A. Gould , M. Asplund , J. Meléndez , S. Lucatello

Recent theoretical yields and chemical evolution models demonstrate that intermediate-mass AGB stars cannot reproduce the observed abundance distributions of O, Na, Mg, and Al. As a further observational test of this finding, we present…

We study the temporal evolution of the 7Li abundance in the gaseous medium for all the components (halo, disk and bulge) of our Galaxy. We adopt nucleosynthesis prescriptions on stellar lithium production based upon recent observational…

Astrophysics · Physics 2016-08-30 Donatella Romano

We model the evolution of the abundances of light elements in carbon-enhanced metal-poor (CEMP) stars, under the assumption that such stars are formed by mass transfer in a binary system. We have modelled the accretion of material ejected…

Astrophysics · Physics 2009-11-13 Richard J. Stancliffe

We propose a new chemical evolution model aimed at explaining the chemical properties of globular clusters (GC) stars. Our model depends upon the existence of (i) a peculiar pre-enrichment phase in the GC's parent galaxy associated with…

Astrophysics of Galaxies · Physics 2009-11-13 Andrea Marcolini , Brad K. Gibson , Amanda I. Karakas , Patricia Sanchez-Blazquez

Chemical abundances provide important clues to the evolution of galaxies. Ionized nebulae are one of the main sources of chemical abundance measurements, especially in external galaxies. Studies of H II regions have shown that the overall…

Astrophysics · Physics 2007-05-23 G. A. Shields

Isotope ratios have opened a new window into the study of the details of stellar evolution, supernovae, and galactic chemical evolution. We present the evolution of the isotope ratios of elemental abundances (from C to Zn) in the solar…

Astrophysics of Galaxies · Physics 2015-05-27 Chiaki Kobayashi , Amanda I. Karakas , Hideyuki Umeda

In the first paper in this series, we proposed a new framework in which to model the chemical evolution of globular clusters. This model, is predicated upon the assumption that clusters form within an interstellar medium enriched locally by…

We present a homogeneous chemical abundance analysis of 16 elements in 190 metal-poor Galactic halo stars (38 program and 152 literature objects). The sample includes 171 stars with [Fe/H] < -2.5, of which 86 are extremely metal poor,…