- ID:
- ivo://CDS.VizieR/J/A+A/508/L17
- Title:
- Abundances in solar analogs
- Short Name:
- J/A+A/508/L17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive the abundance of 19 elements in a sample of 64 stars with fundamental parameters very similar to solar, which minimizes the impact of systematic errors in our spectroscopic 1D-LTE differential analysis, using high-resolution (R~60000), high signal-to-noise ratio (S/N~200) spectra. The estimated errors in the elemental abundances relative to solar are as small as ~0.025dex. The abundance ratios [X/Fe] as a function of [Fe/H] agree closely with previously established patterns of Galactic thin-disk chemical evolution.
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- ID:
- ivo://CDS.VizieR/J/AZh/75/586
- Title:
- Abundances in solar atmosphere
- Short Name:
- J/AZh/75/586
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of the chemical composition of the solar atmosphere is performed using spectrograms of the daylight sky obtained on the ZTS telescope (dispersion 3{AA}/mm, signal-to-noise ration, S/N>100). The chemical composition derived in the framework of a Holweger-Muller atmosphere model are in excellent agreement with the generally accepted values. Analysis based on the models of Bell et al. (1976A&AS...23...37B) and Kurucz (1992RMxAA..23..181K) with Teff=5770K and logg=4.44 failed to give satisfactory results.
- ID:
- ivo://CDS.VizieR/J/AZh/88/750
- Title:
- Abundances in stars of galactic sub-structures
- Short Name:
- J/AZh/88/750
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have determined abundances of copper, zinc, sodium, and aluminium in the atmospheres of 172 F, G, and K dwarf stars (-1.0<[Fe/H]<0.3) belonging to the Galaxy's thin and thick disks and to the Hercules moving group. Our observations were performed with the ELODIE echelle spectrometer on the 1.93-m telescope of the Haute ProvenceObservatory, with a resolving power of R=42000 and signal-to-noise ratio S/N>100. The Na, Al, Cu, and Zn abundances were derived in an LTE approximation; the synthetic spectrum for the copper lines was calculated taking into account super-fine structure of the lines. We analyzed the abundances of these elements as a function of metallicity [Fe/H] for stars of the thin and thick disks of the Galaxy and the Hercules moving group. The Cu abundances and their trends with metallicity are essentially the same in the three studied sub-structures. The mean Al and Zn abundances for stars of the thin and thick disks differ significantly.
- ID:
- ivo://CDS.VizieR/J/ApJS/191/352
- Title:
- Abundances in stars of Milky Way dwarf satellites
- Short Name:
- J/ApJS/191/352
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of Fe, Mg, Si, Ca, and Ti abundances for 2961 stars in eight dwarf satellite galaxies of the Milky Way (MW): Sculptor, Fornax, Leo I, Sextans, Leo II, Canes Venatici I, Ursa Minor, and Draco. For the purposes of validating our measurements, we also observed 445 red giants in MW globular clusters and 21 field red giants in the MW halo. The measurements are based on Keck/DEIMOS medium-resolution spectroscopy (MRS) combined with spectral synthesis. We estimate uncertainties in [Fe/H] by quantifying the dispersion of [Fe/H] measurements in a sample of stars in monometallic globular clusters (GCs). We estimate uncertainties in Mg, Si, Ca, and Ti abundances by comparing to high-resolution spectroscopic abundances of the same stars. For this purpose, a sample of 132 stars with published high-resolution spectroscopy in GCs, the MW halo field, and dwarf galaxies has been observed with MRS. The standard deviations of the differences in [Fe/H] and <[{alpha}/Fe]> (the average of [Mg/Fe], [Si/Fe], [Ca/Fe], and [Ti/Fe]) between the two samples is 0.15 and 0.16, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/438/251
- Title:
- Abundances in stars with giant planets
- Short Name:
- J/A+A/438/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Na, Mg and Al abundances in a set of 98 stars with known giant planets, and in a comparison sample of 41 "single" stars. The results show that the [X/H] abundances (with X = Na, Mg and Al) are, on average, higher in stars with giant planets, a result similar to the one found for iron. However, we did not find any strong difference in the [X/Fe] ratios, for a fixed [Fe/H], between the two samples of stars in the region where the samples overlap. The data was used to study the Galactic chemical evolution trends for Na, Mg and Al and to discuss the possible influence of planets on this evolution. The results, similar to those obtained by other authors, show that the [X/Fe] ratios all decrease as a function of metallicity up to solar values. While for Mg and Al this trend then becomes relatively constant, for Na we find indications of an upturn up to [Fe/H] values close to 0.25dex. For metallicities above this value the [Na/Fe] becomes constant.
- ID:
- ivo://CDS.VizieR/J/A+A/416/1117
- Title:
- Abundances in the early Galaxy
- Short Name:
- J/A+A/416/1117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the framework of the ESO Large Programme "First Stars", very high-quality spectra of some 70 very metal-poor dwarfs and giants were obtained with the ESO VLT and UVES spectrograph. These stars are likely to have descended from the first generation(s) of stars formed after the Big Bang, and their detailed composition provides constraints on issues such as the nature of the first supernovae, the efficiency of mixing processes in the early Galaxy, the formation and evolution of the halo of the Galaxy, and the possible sources of reionization of the Universe. This paper presents the abundance analysis of an homogeneous sample of 35 giants selected from the HK survey of Beers et al. (1992, Cat. <J/AJ/103/1987>, 1999, Cat. <J/AJ/117/981>), emphasizing stars of extremely low metallicity: 30 of our 35 stars are in the range -4.1<[Fe/H]<-2.7, and 22 stars have [Fe/H]<-3.0. Our new VLT/UVES spectra, at a resolving power of R~45000 and with signal-to-noise ratios of 100-200 per pixel over the wavelength range 330-1000 nm, are greatly superior to those of the classic studies of McWilliam et al. (1995AJ....109.2757M) and Ryan et al. (1996ApJ...471..254R).
- ID:
- ivo://CDS.VizieR/J/A+A/410/527
- Title:
- Abundances in the Galactic disk
- Short Name:
- J/A+A/410/527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In table 3 we list all spectral lines that have been used in the determination of abundances. Column 1 gives the wavelength (in Angstrom), column 2 the lower excitation potential (in eV), column 3 the correction factor to the classical Unsoeld damping constant, and column 5 the radiation damping constant. An "S" in column 4 indicates that the broadening by collisions have been taken from Anstee & O'Mara (1995MNRAS.276..859A), Barklem & O'Mara (1997MNRAS.290..102B, 1998MNRAS.300..863B), and Barklem et al. (1998MNRAS.296.1057B, 2000, Cat. <J/A+AS/142/467>), instead of the classical Unsoeld broadening (indicated by a "U"). The solar abundance that is given for each element is the photospheric value from Grevesse & Sauval (1998SSRv...85..161G ). Column 6 gives our adopted log gf - values and column 7 the references. In table 6 we give the derived abundances for all individual elements (atoms and ions). The results for each star consist of three rows. The top row gives the mean abundance, the middle row gives the (1 sigma) standard deviation around the mean, and the third row gives the number of spectral lines that was used in computing the mean. All abundances are given relatively our solar values, which in turn is normalized to the standard photospheric values in Grevesse & Sauval (1998SSRv...85..161G ).
- ID:
- ivo://CDS.VizieR/J/A+A/419/469
- Title:
- Abundances in the galaxy HS 0837+4717
- Short Name:
- J/A+A/419/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of high S/N long-slit spectroscopy with the Multiple Mirror (MMT) and the SAO 6-m (BTA) telescopes, optical imaging with the Wise 1-m telescope and HI observations with the Nancay Radio Telescope of the very metal-deficient (12+log(O/H)=7.64) luminous (M_B_=-18.1mag) blue compact galaxy (BCG) HS 0837+4717.
- ID:
- ivo://CDS.VizieR/J/AJ/133/694
- Title:
- Abundances in the HR 1614 moving group
- Short Name:
- J/AJ/133/694
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present abundances for a sample of F, G, and K dwarfs of the HR 1614 moving group based on high-resolution, high signal-to-noise ratio spectra from the Anglo-Australian Telescope UCLES instrument. Our sample includes stars from Feltzing and Holmberg, as well as from Eggen. Abundances were derived for Na, Mg, Al, Si, Ca, Mn, Fe, Ni, Zr, Ba, Ce, Nd, and Eu.
- ID:
- ivo://CDS.VizieR/J/AJ/150/88
- Title:
- Abundances in the local region. I. G and K giants
- Short Name:
- J/AJ/150/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Parameters and abundances for 1133 stars of spectral types F, G, and K of luminosity class III have been derived. In terms of stellar parameters, the primary point of interest is the disagreement between gravities derived with masses determined from isochrones, and gravities determined from an ionization balance. This is not a new result per se, but the size of this sample emphasizes the severity of the problem. A variety of arguments led to the selection of the ionization-balance gravity as the working value. The derived abundances indicate that the giants in the solar region have Sun-like total abundances and abundance ratios. Stellar evolution indicators have also been investigated with the Li abundances and the [C/Fe] and C/O ratios, indicating that standard processing has been operating in these stars. The more salient result for stellar evolution is that the [C/Fe] data across the red-giant clump indicates the presence of mass-dependent mixing in accord with standard stellar evolution predictions.
