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Showing 1 to 10 of 10 for “"asymptotic giant branch stars"”.
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The galactic evolution ofs-process elements via asymptotic giant branch stars
We attempt to study the ability of asymptotic giant branch stars to produce s-process elements as a function of initial mass and metallicity. The normal methods of extracting information from spectroscopic observations of the surfaces of these stars are reviewed and it is shown how misleading some …
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Neutron exposure and neutron flux in Asymptotic Giant Branch stars: a study of neutron capture cross sections of Zr isotopes
Nuclear astrophysics is an interdisciplinary branch of physics involving close collaboration among researchers in various subfields of nuclear physics and astrophysics, with significant emphasis in areas such as stellar modeling, measurement and theoretical estimation of nuclear reaction rates, …
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Multi-element isotopic analyses of presolar graphite grains from the Orgueil meteorite
… majority seems to originate from low-metallicity asymptotic giant branch stars. Evidence for this comes from correlated <super>12</super>C and <super>30</super>Si enrichments. In low-metallicity asymptotic giant branch stars, <super>12</super>C and <super>29,30</super>Si that are produced in the …
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Spectroscopic surface brightness fluctuations
… measure, but due to its sensitive to bright stars also used to study evolved stars in unresolved stellar populations. The wide-field spectrograph MUSE offers the possibility to apply this technique for the first time to spectroscopic data. In this thesis I develop the spectroscopic SBF …
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Stellar Halos: modelling formation in the L-Galaxies 2020 semi-analytic model
… profile. In the latter case, the stellar halo stars follow the distribution of the galaxy's dark matter. It was found that a combination of an NFW profile and gradual disruption provided the best results across the widest range of literature data, namely measurements of stellar halo mass, total …
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Star formation, quenching and chemical enrichment in local galaxies from integral field spectroscopy
… a central point source but to hot evolved (post-asymptotic giant branch) stars. In light of this, I suggest a new classification scheme for galaxies based on their line emission. By analysing the colours, star formation rates, morphologies, gas and stellar kinematics and environmental properties …
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Isotopic and Elemental Compositions of Stardust and Protosolar Dust Grains in Primitive Meteorites
… come from less than 2.2<italic>M<italic>├» Red Giant or Asymptotic Giant Branch stars. The second most abundant fraction of grains show large <super>18<super>O excesses and come from core collapse supernovae. The next most abundant fraction of grains comes from high metallicity AGB stars of …
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Correlated NanoSIMS, TEM, and XANES Studies of Presolar Grains
… in high-density presolar graphite grains from Asymptotic Giant Branch stars, whose grains are typically microstructurally distinct from SN graphite grains. These vastly different stellar environments briefly formed similar nanocrystalline structures before diverging in the structure of their …
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Mapping the interstellar magnetic field: Observations of the Goldreich-Kylafis effect towards late-type evolved stars and star-forming regions
… magnetic fields in both late-type evolved stars and star-forming regions. Observations of linearly polarized molecular line transitions arising from the Goldreich-Kylafis (G-K) effect provide valuable insight into the magnetic field geometry in these sources. Through observing with CARMA, …
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Observational and theoretical studies of SiO maser polarization toward late-type evolved stars: Insights from EVPA reversal features
… of SiO masers toward late-type evolved stars continue to be a subject of debate. Possible primary sources include the local magnetic field or anisotropic pumping, while additional polarization may arise due to conversion from linear to circular modes through scattering or Faraday …