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151. Abundances in the local region. III. Southern dwarfs
ID:
ivo://CDS.VizieR/J/AJ/155/111
Title:
Abundances in the local region. III. Southern dwarfs
Short Name:
J/AJ/155/111
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stellar parameters and abundances have been derived from a sample of 907 F, G, and K dwarfs. The high-resolution, high signal-to-noise spectra utilized were acquired with the HARPS spectrograph of the European Southern Observatory. The stars in the sample with -0.2<[Fe/H]<+0.2 have abundances that strongly resemble that of the Sun, except for the lithium content and the lanthanides. Near the solar temperature, stars show two orders of magnitude range in lithium content. The average content of stars in the local region appears to be enhanced at about the +0.1 level relative to the Sun for the lanthanides. There are over 100 planet hosts in this sample, and there is no discernible difference between them and the non-hosts regarding their lithium content.
152. Abundances in the Sgr dSph
ID:
ivo://CDS.VizieR/J/A+A/414/503
Title:
Abundances in the Sgr dSph
Short Name:
J/A+A/414/503
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on abundances of O, Mg, Si, Ca and Fe for 10 giants in the Sgr dwarf spheroidal derived from high resolution spectra obtained with UVES at the 8.2m Kueyen-VLT telescope. The iron abundance spans the range -0.8<~[Fe/H]<~0.0 and the dominant population is relatively metal-rich with [Fe/H]~-0.25.
153. Abundances in the ultra-faint dwarf gal. GruI & TriII
ID:
ivo://CDS.VizieR/J/ApJ/870/83
Title:
Abundances in the ultra-faint dwarf gal. GruI & TriII
Short Name:
J/ApJ/870/83
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present high-resolution spectroscopy of four stars in two candidate ultra-faint dwarf galaxies (UFDs), GrusI (GruI) and TriangulumII (TriII). Neither object currently has a clearly determined velocity dispersion, placing them in an ambiguous region of parameter space between dwarf galaxies and globular clusters (GCs). No significant metallicity difference is found for the two GruI stars, but both stars are deficient in neutron-capture elements. We verify previous results that TriII displays significant spreads in metallicity and [{alpha}/Fe]. Neutron-capture elements are not detected in our TriII data, but we place upper limits at the lower envelope of Galactic halo stars, consistent with previous very low detections. Stars with similarly low neutron-capture element abundances are common in UFDs but rare in other environments. This signature of low neutron-capture element abundances traces chemical enrichment in the least massive star-forming dark matter halos and further shows that the dominant sources of neutron-capture elements in metal-poor stars are rare. In contrast, all known GCs have similar ratios of neutron-capture elements to those of halo stars, suggesting that GCs do not form at the centers of their own dark matter halos. The low neutron-capture element abundances may be the strongest evidence that GruI and TriII are (or once were) galaxies rather than GCs, and we expect future observations of these systems to robustly find nonzero velocity dispersions or signs of tidal disruption. However, the nucleosynthetic origin of this low neutron-capture element floor remains unknown.
154. Abundances of A-F stars
ID:
ivo://CDS.VizieR/J/A+A/398/1121
Title:
Abundances of A-F stars
Short Name:
J/A+A/398/1121
Date:
21 Oct 2021
Publisher:
CDS
Description:
Fundamental parameters and abundances of 140 A and F-type stars are presented. The barycentric Julian dates and signal-to-noise ratios are also given.
155. Abundances of Baade's Window K giants
ID:
ivo://CDS.VizieR/J/ApJ/636/821
Title:
Abundances of Baade's Window K giants
Short Name:
J/ApJ/636/821
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results of a new abundance survey of the Milky Way bulge based on Keck HIRES spectra of 27 K giants in the Baade's Window (l=1{deg},b=-4{deg}) field. The spectral data used in this study are of much higher resolution and signal-to-noise ratio than previous optical studies of Galactic bulge stars. The [Fe/H] values of our stars, which range between 1.29 and +0.51, were used to recalibrate large low-resolution surveys of bulge stars. Our best value for the mean [Fe/H] of the bulge is -0.10+/-0.04. This mean value is similar to the mean metallicity of the local disk and indicates that there cannot be a strong metallicity gradient inside the solar circle. The metallicity distribution of stars confirms that the bulge does not suffer from the so-called G dwarf problem. This paper also details the new abundance techniques necessary to analyze very metal-rich K giants, including a new Fe line list and regions of low blanketing for continuum identification.
156. Abundances of 26 barium stars. I.
ID:
ivo://CDS.VizieR/J/A+A/454/895
Title:
Abundances of 26 barium stars. I.
Short Name:
J/A+A/454/895
Date:
21 Oct 2021
Publisher:
CDS
Description:
The abundances for Na, Al, alpha-, iron-peak, s-, and r-elements have been derived by using spectrum synthesis for a sample of 26 barium stars, including dwarf barium stars. High-resolution spectra were obtained with the FEROS spectrograph at the ESO-1.52m Telescope, along with photometric data with Fotrap at the Zeiss telescope at the LNA.
157. Abundances of 26 barium stars. II.
ID:
ivo://CDS.VizieR/J/A+A/454/917
Title:
Abundances of 26 barium stars. II.
Short Name:
J/A+A/454/917
Date:
21 Oct 2021
Publisher:
CDS
Description:
The aim of this work is to quantify the contributions of the s-, r-, and p-processes for the total abundance of heavy elements from abundances derived for a sample of 26 barium stars. The abundances of the sample stars were compared to those of normal stars, thus identifying the fraction relative to the main component of the s-process s. The fittings of the sigmaN curves (neutron-capture cross-section times abundance, plotted against atomic mass number) for the sample stars suggest that the material from the companion asymptotic giant branch star had approximately the solar isotopic composition as concerns fractions of abundances relative to the s-process main component.
158. Abundances of BHB stars in NGC 1904
ID:
ivo://CDS.VizieR/J/A+A/434/235
Title:
Abundances of BHB stars in NGC 1904
Short Name:
J/A+A/434/235
Date:
21 Oct 2021
Publisher:
CDS
Description:
The abundance measurements are based on high-resolution optical spectroscopical data, obtained during 2 observing runs with the Ultraviolet and Visual Echelle Spectrograph mounted on Kueyen (Very Large Telescope UT2). Ten target stars in the extended blue horizontal branch of the Galactic globular cluster NGC 1904 (M79) have been analysed.
159. Abundances of 3 bright extremely metal-poor giants
ID:
ivo://CDS.VizieR/J/ApJ/864/43
Title:
Abundances of 3 bright extremely metal-poor giants
Short Name:
J/ApJ/864/43
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present detailed chemical abundances of three new bright (V~11), extremely metal-poor ([Fe/H]~-3.0), r-process-enhanced halo red giants based on high-resolution, high-S/N Magellan/MIKE spectra. We measured abundances for 20-25 neutron-capture elements in each of our stars. J1432-4125 is among the most r-process-rich r-II stars, with [Eu/Fe]=+1.44+/-0.11. J2005-3057 is an r-I star with [Eu/Fe]=+0.94+/-0.07. J0858-0809 has [Eu/Fe]=+0.23+/-0.05 and exhibits a carbon abundance corrected for an evolutionary status of [C/Fe]_corr_=+0.76, thus adding to the small number of known carbon-enhanced r-process stars. All three stars show remarkable agreement with the scaled solar r-process pattern for elements above Ba, consistent with enrichment of the birth gas cloud by a neutron star merger. The abundances for Sr, Y, and Zr, however, deviate from the scaled solar pattern. This indicates that more than one distinct r-process site might be responsible for the observed neutron-capture element abundance pattern. Thorium was detected in J1432-4125 and J2005-3057. Age estimates for J1432-4125 and J2005-3057 were adopted from one of two sets of initial production ratios each by assuming the stars are old. This yielded individual ages of 12+/-6Gyr and 10+/-6Gyr, respectively.
160. Abundances of bright metal-poor stars
ID:
ivo://CDS.VizieR/J/ApJ/797/13
Title:
Abundances of bright metal-poor stars
Short Name:
J/ApJ/797/13
Date:
21 Oct 2021
Publisher:
CDS
Description:
The chemical abundances of large samples of extremely metal-poor (EMP) stars can be used to investigate metal-free stellar populations, supernovae, and nucleosynthesis as well as the formation and galactic chemical evolution of the Milky Way and its progenitor halos. However, current progress on the study of EMP stars is being limited by their faint apparent magnitudes. The acquisition of high signal-to-noise spectra for faint EMP stars requires a major telescope time commitment, making the construction of large samples of EMP star abundances prohibitively expensive. We have developed a new, efficient selection that uses only public, all-sky APASS optical, 2MASS near-infrared, and WISE mid-infrared photometry to identify bright metal-poor star candidates through their lack of molecular absorption near 4.6 microns.

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