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- ID:
- ivo://CDS.VizieR/J/A+A/465/185
- Title:
- Element abundances of 7 stars of NGC 6253
- Short Name:
- J/A+A/465/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a big FLAMES survey of 10 Galactic open clusters aiming at different goals. One of them is the determination of chemical abundances, in order to put constraints on the radial metallicity gradient in the disk and its evolution. One of the sample clusters is the very metal rich NGC 6253. We have obtained UVES high resolution spectra of seven candidate clusters members (from the turn off up to the red clump) with the goal of determining the chemical composition of NGC 6253 and to investigate its origin and role in the interpretation of the radial metallicity gradient in the disk.
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/1329
- Title:
- Elemental abundances for 176 stars
- Short Name:
- J/MNRAS/367/1329
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed an abundance analysis for F- and G- dwarfs of the Galactic thick-disc component. A sample of 176 nearby (d<=150pc) thick-disc candidate stars was chosen from the Hipparcos catalogue and subjected to a high-resolution spectroscopic analysis. Using accurate radial velocities combined with the Hipparcos astrometry, kinematics (U, V and W) and Galactic orbital parameters were computed. We estimate the probability for a star to belong to the thin disc, the thick disc or the halo. With a probability P>=70 per cent taken as certain membership, we assigned 95 stars to the thick disc, 13 to the thin disc, and 20 to the halo. The remaining 48 stars in the sample cannot be assigned with reasonable certainty to one of the three components. Abundances of C, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Ba, Ce, Nd and Eu have been obtained.
- ID:
- ivo://CDS.VizieR/J/MNRAS/364/272
- Title:
- Elemental abundances in Blanco 1
- Short Name:
- J/MNRAS/364/272
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-resolution spectroscopy is used to determine the detailed chemical abundances of a group of eight F- and G-type stars in the young open cluster Blanco 1. An average [Fe/H] of +0.04+/-0.02 (internal error)+/-0.04 (external error) is found, considerably lower than a previous spectroscopic estimate for this cluster. The difference is due mainly to our adoption of significantly cooler temperatures that are consistent with both photometric and spectroscopic constraints. Blanco 1 exhibits subsolar [Ni/Fe](0.18+/-0.01+/-0.01), [Si/Fe](0.09+/-0.02+/-0.03), [Mg/Fe](0.14+/-0.02+/-0.03) and [Ca/Fe](0.09+/-0.03+/-0.03); ratios that are not observed among nearby field stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/563
- Title:
- Elemental abundances in Hyades supercluster
- Short Name:
- J/MNRAS/415/563
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The existence of a kinematically defined moving group of stars centred at U=-40, V=-17km/s, referred to as the Hyades supercluster, has been suggested to be the debris of an originally large star-forming event, with its core being the present-day Hyades open cluster. Using high-resolution UV-Visual Echelle Spectrograph (UVES) spectra, we present the elemental abundances for a range of alpha, Fe-peak and neutron-capture elements for 26 proposed supercluster stars. Our results show that the sample stars display a heterogeneous abundance distribution, with a clump around [Fe/H]=+0.15. We also calculate stellar radial velocities and U, V, W space velocities. Enforcing strict chemical and kinematical membership criteria, we find that four supercluster stars share the Hyades open cluster abundances and kinematics, while many of the remaining stars fit the disc field kinematics and abundance range. We discuss our findings in the context of the Hyades supercluster being a dispersed star-forming remnant, a stellar stream of purely dynamical origin or a result of several processes.
- ID:
- ivo://CDS.VizieR/J/AJ/130/1111
- Title:
- Elemental abundances of field red giants
- Short Name:
- J/AJ/130/1111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We summarize a selection process to identify red giants in the direction of the southern warp of the Galactic disk, employing VI_C_ photometry and multi-object spectroscopy.
- ID:
- ivo://CDS.VizieR/J/AJ/155/68
- Title:
- Elemental abundances of KOIs in APOGEE. I.
- Short Name:
- J/AJ/155/68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has observed ~600 transiting exoplanets and exoplanet candidates from Kepler (Kepler Objects of Interest, KOIs), most with >=18 epochs. The combined multi-epoch spectra are of high signal-to-noise ratio (typically >=100) and yield precise stellar parameters and chemical abundances. We first confirm the ability of the APOGEE abundance pipeline, ASPCAP, to derive reliable [Fe/H] and effective temperatures for FGK dwarf stars - the primary Kepler host stellar type - by comparing the ASPCAP-derived stellar parameters with those from independent high-resolution spectroscopic characterizations for 221 dwarf stars in the literature. With a sample of 282 close-in (P<100 days) KOIs observed in the APOGEE KOI goal program, we find a correlation between orbital period and host star [Fe/H] characterized by a critical period, P_crit_=8.3_-4.1_^+0.1^ days, below which small exoplanets orbit statistically more metal-enriched host stars. This effect may trace a metallicity dependence of the protoplanetary disk inner radius at the time of planet formation or may be a result of rocky planet ingestion driven by inward planetary migration. We also consider that this may trace a metallicity dependence of the dust sublimation radius, but we find no statistically significant correlation with host T_eff_ and orbital period to support such a claim.
- ID:
- ivo://CDS.VizieR/J/AJ/159/46
- Title:
- Elemental abundances of 416 stars in 5 dSphs of M31
- Short Name:
- J/AJ/159/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep spectroscopy from Keck/DEIMOS (DEep Imaging Multi-Object Spectrograph) of Andromeda I, III, V, VII, and X, all of which are dwarf spheroidal satellites (dSphs) of M31. The sample includes 256 spectroscopic members across all five dSphs. We confirm previous measurements of the velocity dispersions and dynamical masses, and we provide upper limits on bulk rotation. Our measurements confirm that M31 satellites obey the same relation between stellar mass and stellar metallicity as Milky Way (MW) satellites and other dwarf galaxies in the Local Group. The metallicity distributions show trends with stellar mass that are similar to those of MW satellites, including evidence in massive satellites for external influence, like pre-enrichment or gas accretion. We present the first measurements of individual element ratios, like [Si/Fe], in the M31 system, as well as measurements of the average [{alpha}/Fe] ratio. The trends of [{alpha}/Fe] with [Fe/H] also follow the same galaxy mass-dependent patterns as MW satellites. Less massive galaxies have more steeply declining slopes of [{alpha}/Fe] that begin at lower [Fe/H]. Finally, we compare the chemical evolution of M31 satellites to M31's Giant Stellar Stream and smooth halo. The properties of the M31 system support the theoretical prediction that the inner halo is composed primarily of massive galaxies that were accreted early. As a result, the inner halo exhibits higher [Fe/H] and [{alpha}/Fe] than surviving satellite galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/811/78
- Title:
- Elemental depletions in the Magellanic Clouds
- Short Name:
- J/ApJ/811/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the composition of gas and dust in the Large and Small Magellanic Clouds (LMC and SMC) using UV absorption spectroscopy. We measure PII and FeII along 84 spatially distributed sightlines toward the MCs using archival Far Ultraviolet Spectroscopic Explorer observations. For 16 of those sightlines, we also measure SiII, CrII, and ZnII from new Hubble Space Telescope Cosmic Origins Spectrograph observations. We analyze these spectra using a new spectral line analysis technique based on a semi-parametric Voigt profile model. We have combined these measurements with HI and H_2_ column densities and reference stellar abundances from the literature to derive gas-phase abundances, depletions, and gas-to-dust ratios (GDRs). Of our 84 P and 16 Zn measurements, 80 and 13, respectively, are depleted by more than 0.1dex, suggesting that P and Zn abundances are not accurate metallicity indicators at and above the metallicity of the SMC. Si, Cr, and Fe are systematically less depleted in the SMC than in the Milky Way (MW) or LMC. The minimum Si depletion in the SMC is consistent with zero. We find GDR ranges of 190-565 in the LMC and 480-2100 in the SMC, which is broadly consistent with GDRs from the literature. These ranges represent actual location to location variation and are evidence of dust destruction and/or growth in the diffuse neutral phase of the interstellar medium. Where they overlap in metallicity, the gas-phase abundances of the MW, LMC, and SMC and damped Ly{alpha} systems evolve similarly with metallicity.
- ID:
- ivo://CDS.VizieR/J/other/IBVS/5480
- Title:
- Elements for 80 eclipsing binaries
- Short Name:
- J/other/IBVS/548
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This research presents new elements for 80 eclipsing binaries found with the help of the ASAS-3, Hipparcos and TASS databases.