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Heavy-Element Dispersion In The Metal-Poor Globular Cluster M92
(2011-07)
Dispersion among the light elements is common in globular clusters (GCs), while dispersion among heavier elements is less common. We present detection of r-process dispersion relative to Fe in 19 red giants of the metal-poor ...
New Rare Earth Element Abundance Distributions for the Sun and Five R-Process-Rich Very Metal-Poor Stars
(2009-05)
We have derived new abundances of the rare earth elements Pr, Dy, Tm, Yb, and Lu for the solar photosphere and for five very metal-poor, neutron-capture r-process-rich giant stars. The photospheric values for all five ...
VLT/FLAMES Spectroscopy Of Red Giant Branch Stars In The Fornax Dwarf Spheroidal Galaxy
(2014-12)
Context. Fornax is one of the most massive dwarf spheroidal galaxies in the Local Group. The Fornax field star population is dominated by intermediate age stars but star formation was going on over almost its entire history. ...
Chemical Compositions Of Thin-Disk, High-Metallicity Red Horizontal-Branch Field Stars
(2012-07)
We present a detailed abundance analysis and atmospheric parameters of 76 stars from a survey to identify field Galactic red horizontal-branch (RHB) stars. High-resolution echelle spectra (R similar or equal to 60,000, S/N ...
VLT/FLAMES Spectroscopy Of Red Giant Branch Stars In The Fornax Dwarf Spheroidal Galaxy
(2014-12)
Context. Fornax is one of the most massive dwarf spheroidal galaxies in the Local Group. The Fornax field star population is dominated by intermediate age stars but star formation was going on over almost its entire history. ...
Hubble Space Telescope Near-Ultraviolet Spectroscopy Of The Bright CEMP-No Star BD+44 Degrees 493
(2014-07)
We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the extremely metal-poor star BD+44 degrees 493 a ninth magnitude subgiant with [Fe/H] = -3.8 and enhanced carbon, based on data ...
Improved Laboratory Transition Probabilities for Ce II, Application to the Cerium Abundances of the Sun and Five R-Process-Rich, Metal-Poor Stars, and Rare Earth Lab Data Summary
(2009-05)
Recent radiative lifetime measurements accurate to +/- 5% using laser-induced fluorescence (LIF) on 43 even-parity and 15 odd-parity levels of Ce II have been combined with new branching fractions measured using a Fourier ...
The Two Metallicity Groups Of The Globular Cluster M22: A Chemical Perspective
(2011-08)
We present a detailed chemical composition analysis of 35 red giant stars in the globular cluster M22. High resolution spectra for this study were obtained at five observatories, and analyzed in a uniform manner. We have ...
Characterizing The Heavy Elements In Globular Cluster M22 And An Empirical S-Process Abundance Distribution Derived From The Two Stellar Groups
(2011-11)
We present an empirical s-process abundance distribution derived with explicit knowledge of the r-process component in the low-metallicity globular cluster M22. We have obtained high-resolution, high signal-to-noise spectra ...
New Detections Of Arsenic, Selenium, And Other Heavy Elements In Two Metal-Poor Stars
(2014-08)
We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope to obtain new high-quality spectra covering the 1900 <= lambda <= 2360 angstrom wavelength range for two metal-poor stars, HD 108317 and ...