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- ID:
- ivo://CDS.VizieR/J/AJ/120/1841
- Title:
- Abundances and Kinematics of Halo and Disk Stars
- Short Name:
- J/AJ/120/1841
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The table gives the equivalent widths of the 168 stars used in the abundance analyses. For stars that may have multiple observations the mean value of the measurements is given for each line. Only lines used in the final abundance analysis are provided.
- ID:
- ivo://CDS.VizieR/J/ApJ/754/L38
- Title:
- Abundances and radial velocities of M13 giants
- Short Name:
- J/ApJ/754/L38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present O, Na, and Fe abundances, as well as radial velocities, for 113 red giant branch (RGB) and asymptotic giant branch (AGB) stars in the globular cluster M13. The abundances and velocities are based on spectra obtained with the WIYN-Hydra spectrograph, and the observations range in luminosity from the horizontal branch (HB) to RGB tip. The results are examined in the context of recent globular cluster formation scenarios. We find that M13 exhibits many key characteristics that suggest its formation and chemical enrichment are well described by current models. Some of these observations include the central concentration of O-poor stars, the notable decrease in [O/Fe] (but small increase in [Na/Fe]) with increasing luminosity that affects primarily the "extreme" population, the small fraction of stars with halo-like composition, and the paucity of O-poor AGB stars. In agreement with recent work, we conclude that the most O-poor M13 giants are likely He-enriched and that most (all?) O-poor RGB stars evolve to become extreme HB and AGB-manqu\'e stars. In contrast, the "primordial" and "intermediate" population stars appear to experience standard HB and AGB evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/511/L10
- Title:
- Abundances and space velocities of 94 stars
- Short Name:
- J/A+A/511/L10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Precise abundance ratios are determined for 94 dwarf stars with 5200<Teff<6300K, -1.6<[Fe/H]<-0.4, and distances D<~335pc. Most of them have halo kinematics, but 16 thick-disk stars are included. Equivalent widths of atomic lines are measured from VLT/UVES and NOT/FIES spectra with resolutions R~55000 and R~40000, respectively. An LTE abundance analysis based on MARCS models is applied to derive precise differential abundance ratios of Na, Mg, Si, Ca, Ti, Cr, and Ni with respect to Fe.
- ID:
- ivo://CDS.VizieR/J/AJ/150/187
- Title:
- Abundances and stellar parameters of LAMOST stars
- Short Name:
- J/AJ/150/187
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe an application of the SEGUE Stellar Parameter Pipeline (SSPP) to medium-resolution stellar spectra obtained by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), in order to determine estimates of the stellar atmospheric parameters (T_eff_, logg, and [Fe/H]) and the abundance ratios ([{alpha}/Fe] and [C/Fe]). By performing a coordinate match with the LAMOST stellar database, we selected stars with LAMOST spectra in common with stars having available spectroscopy from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), the RAdial Velocity Experiment (RAVE), and the Sloan Extension for Galactic Understanding and Exploration (SEGUE). We ran the selected LAMOST stellar spectra from each survey through SSPP, and compared the stellar parameters down to signal-to-noise ratio (S/N) of 10 and chemical abundances down to S/N=20 derived by SSPP with those determined by the APOGEE, RAVE, and SEGUE software pipelines. Our results show that the derived stellar parameters generally agree quite well, even though there exist some small systematic offsets with small scatter in T_eff_, logg, and [Fe/H], due to the use of different temperature scales, abundance scales, and calibrations adopted by each survey. Comparison of the [{alpha}/Fe] determinations for LAMOST spectra suggests no sign of significant systematic offsets (< -0.04dex), with a small scatter (<0.08dex) relative to stars in common with APOGEE and SEGUE. The [C/Fe] estimates determined for the LAMOST spectra also exhibit good agreement, with a very small offset (~0.01dex) and scatter (~0.12dex) relative to the SEGUE stars, while there exists about a -0.19dex offset, with a small scatter of ~0.13dex, for the APOGEE sample. Due to the existence of small offsets in the stellar parameters and abundances among difference data sets, optimal results when combining the different data sets will be obtained by removing the offsets. Once accomplished, the stellar parameters and chemical abundances estimated by SSPP from the LAMOST stellar spectra should provide a reliable database for studies of the Galactic disk and halo systems.
- ID:
- ivo://CDS.VizieR/J/A+AS/113/299
- Title:
- Abundances and velocities for cluster giants
- Short Name:
- J/A+AS/113/299
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large dataset consisting of giants in the field, and in open and globular clusters. A total of 122 giants were observed in the fields of 8 open clusters. A total of 342 giants were observed in the fields of 25 globular clusters. A total of 36 field stars with well known abundances and luminosities were also observed. Table 8 lists the spectral indices measured for the giants observed with the Argus and Red Channel spectrographs during 1991 and 1992. The central and continuum passbands for these indices are defined in Table 6.
- ID:
- ivo://CDS.VizieR/J/AJ/130/2140
- Title:
- Abundances and velocities in globular clusters
- Short Name:
- J/AJ/130/2140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled a sample of globular clusters with high-quality stellar abundances from the literature to compare to the chemistries of stars in the Galaxy and in dwarf spheroidal galaxies. Of the 45 globular clusters examined, 29 also have kinematic information. Most of the globular clusters belong to the Galactic halo; however, a significant number have disk kinematics or belong to the bulge.
- ID:
- ivo://CDS.VizieR/J/ApJ/754/91
- Title:
- Abundances and velocities of NGC 6397 stars
- Short Name:
- J/ApJ/754/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used three sets of high-resolution spectra acquired with the multifiber facility FLAMES at the Very Large Telescope of the European Southern Observatory to investigate the chemical and kinematical properties of a sample of 42 horizontal branch (HB) stars, 18 blue straggler stars (BSSs), and 86 main-sequence (MS) turnoff (TO) and sub-giant branch stars in the nearby globular cluster NGC 6397. We measured rotational velocities and Fe, O, and Mg abundances. All of the unevolved stars in our sample have low rotational velocites (vsin i<10km/s), while the HB stars and BSSs show a broad distribution, with values ranging from 0 to ~70km/s. For HB stars with T<10500K there is a clear temperature-oxygen anticorrelation that can be understood if the star position along the HB is mainly determined by the He content. The hottest BSSs and HB stars (with temperatures T>8200K and T>10500K, respectively) also show significant deviations in their iron abundance with respect to the cluster metallicity (as traced by the unevolved stars, [Fe/H]=-2.12). While similar chemical patterns have already been observed in other hot HB stars, this is the first evidence ever collected for BSSs. We interpret these abundance anomalies as due to the metal radiative levitation, occurring in stars with shallow or no convective envelopes.
- ID:
- ivo://CDS.VizieR/J/A+A/569/A55
- Title:
- Abundances and vsini for 348 red giants
- Short Name:
- J/A+A/569/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Li and alpha-elements abundances, as well as rotational velocities for 348 stars. Li has been detected in 92 stars, of which 82 are giants. Those data ware used to investigate various channels of Li enrichment in giants.
- ID:
- ivo://CDS.VizieR/J/ApJ/743/140
- Title:
- Abundances (Be,{alpha}) in metal-poor stars
- Short Name:
- J/ApJ/743/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The light elements, Li, Be, and B, provide tracers for many aspects of astronomy including stellar structure, Galactic evolution, and cosmology. We have made observations of Be in 117 metal-poor stars ranging in metallicity from [Fe/H]=-0.5 to -3.5 with Keck I/HIRES. Our spectra are high resolution (~42000) and high signal to noise (the median is 106 per pixel). We have determined the stellar parameters spectroscopically from lines of FeI, FeII, TiI, and TiII. The abundances of Be and O were derived by spectrum synthesis techniques, while abundances of Fe, Ti, and Mg were found from many spectral line measurements. We have kinematic information on 114 stars in our sample and they divide equally into dissipative and accretive stars.
