- ID:
- ivo://CDS.VizieR/J/AZh/82/453
- Title:
- Catalogue of spectroscopic abundances in stars
- Short Name:
- J/AZh/82/453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We submit the compiled catalogue of effective temperatures, surface gravities, abundances of iron and magnesium, distances, velocity components, and orbital parameters for stars of solar vicinity. Atmospheric parameters and iron abundances was determined by averaging of published values, which was found from synthetic analysis of high resolution spectra on the basis of 1809 determination from 31 publications. Relative magnesium abundances for 876 dwarfs and subgiants were determined as a result of three-step iteration procedure of averaging with giving weight to each publication and each individual determination. The systematic shifts for each scale relative to reduced main scale was taken into account. We suppose that survey completeness of publications with volume more than 5 stars up to December 2003 is 90%. Spatial velocity components for most majority stars were determined on the stellar data from present day high-precision observations. Galactic orbital parameter were calculated using the Galactic model, which includes a spherical bulge, disk, and extended massive halo.
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- ID:
- ivo://CDS.VizieR/III/121
- Title:
- Catalogue of stellar abundances
- Short Name:
- III/121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue, compiled at the Torun Observatory, contains the published abundances.
- ID:
- ivo://CDS.VizieR/J/A+A/356/529
- Title:
- Catalogue of wide binaries
- Short Name:
- J/A+A/356/529
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The list contains a total of 131 binaries (115 systems) belonging to the halo or high-velocity disk. Of these, 122 correspond to wide binaries, that is, binaries with expected major semiaxes larger than 25 AU. The catalogue was constructed by identifying common proper-motion companions to the high-velocity and metal-poor stars studied by Schuster and collaborators (SN: Schuster and Nissen 1988A&AS...73..225S, SPC: Schuster, Parrao and Contreras, 1993, Cat. <J/A+AS/97/951>). Based on Stromgren photometry, Schuster et al. obtained distances, metallicities and ages for their stars. For each star of the SN and SPC catalogues a machine search for common proper-motion companions was made among the NLTT (Cat. <I/98>) stars within 12 minutes of arc. This initial list was checked to avoid errors due to misidentifications, duplicate entries, etc., and was supplemented with some companions listed in the LDS (Luyten, 1987, Cat. <I/130>) and not present in the NLTT (mostly from the southern hemisphere), as well as with additional common-proper- motion companions found in the CCDM (Dommanget and Nys, 1994, Cat. <I/211>). Additional close companions found in the CCDM were retained only if an orbit was given, or if their separations were of less than 1". Wider companions were usually eliminated, unless convincing evidence of their sharing the proper motion of the primary was found. Distances to the primaries were updated using the Hipparcos (Cat. <I/239>) catalogue. The data in the list are as follows (for details see the main paper): The first column contains the Hipparcos number, when available. Column 2 contains other identifications of the star. In the third column its multiplicity is indicated. Column 4 contains the adopted distance to the star. Columns 5 and 6 contain the absolute visual magnitudes of the primary and secondary, respectively. The angular separation between the components is given in Column 7, and the expected value of the major semiaxes in Column 8. Columns 9 and 10 contain the metallicity of the primary and its age, as determined by Schuster and collaborators. The individual ages listed were kindly provided by W. J. Schuster. The peculiar velocity of the binary is given in Column 11. Columns 12 to 15 contain the main galactic orbital parameters; we list the apocentric distance, Rmax, as well as the maximum distance away from the galactic plane reached by the star |zmax|, and the three-dimensional eccentricity e of its galactic orbit. The last column contains various notes.
- ID:
- ivo://CDS.VizieR/J/ApJ/921/91
- Title:
- Catastrophic cooling in superwinds. II.
- Short Name:
- J/ApJ/921/91
- Date:
- 15 Nov 2021
- Publisher:
- CDS
- Description:
- Superwinds and superbubbles driven by mechanical feedback from super star clusters (SSCs) are common features in many star-forming galaxies. While the adiabatic fluid model can well describe the dynamics of superwinds, several observations of starburst galaxies revealed the presence of compact regions with suppressed superwinds and strongly radiative cooling, i.e., catastrophic cooling. In the present study, we employ the non-equilibrium atomic chemistry and cooling package MAIHEM, built on the FLASH hydrodynamics code, to generate a grid of models investigating the dependence of cooling modes on the metallicity, SSC outflow parameters, and ambient density. While gas metallicity plays a substantial role, catastrophic cooling is more sensitive to high mass-loading and reduced kinetic heating efficiency. Our hydrodynamic simulations indicate that the presence of a hot superbubble does not necessarily imply an adiabatic outflow, and vice versa. Using CLOUDY photoionization models, we predict UV and optical line emission for both adiabatic and catastrophic cooling outflows, for radiation-bounded and partially density-bounded models. Although the line ratios predicted by our radiation-bounded models agree well with observations of star-forming galaxies, they do not provide diagnostics that unambiguously distinguish the parameter space of catastrophically cooling flows. Comparison with observations suggests the possibility of minor density bounding, non-equilibrium ionization, and/or observational bias toward the central outflow regions.
- ID:
- ivo://CDS.VizieR/J/A+A/580/A121
- Title:
- CaT/[Fe/H] calibration for Galactic bulge stars
- Short Name:
- J/A+A/580/A121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new calibration of the calcium II triplet equivalent widths versus [Fe/H], constructed upon K giant stars in the Galactic bulge. This calibration will be used to derive iron abundances for the targets of the GIBS survey, and is in general especially well suited for solar and supersolar metallicity giants, which are typical of external massive galaxies. To obtain the calibration, about 150 bulge K giants were observed with the GIRAFFE spectrograph at the VLT with a resolution of R~20000 and at R~6000. In the first case, the spectra allowed us to directly determine the Fe abundances from several unblended Fe lines, deriving what we call here high-resolution [Fe/H] measurements. The low-resolution spectra allowed us to measure equivalent widths of the two strongest lines of the near-infrared calcium II triplet at 8542 and 8662{AA}. By comparing the two measurements, we derived a relation between calcium equivalent widths and [Fe/H] that is linear over the metallicity range probed here, -1<[Fe/H]<+0.7. By adding a small second-order correction based on literature globular cluster data, we derived the unique calibration equation [Fe/H]_CaT_=-3.150+0.432W'+0.006W'^2^, with an rms dispersion of 0.197dex, valid across the whole metallicity range -2.3<[Fe/H]<+0.7.
- ID:
- ivo://CDS.VizieR/J/ApJS/194/15
- Title:
- CCCP: Carina's diffuse X-ray emission
- Short Name:
- J/ApJS/194/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a 1.42deg^2^ mosaic of diffuse X-ray emission in the Great Nebula in Carina from the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer camera. After removing >14000 X-ray point sources from the field, we smooth the remaining unresolved emission, tessellate it into segments of similar apparent surface brightness, and perform X-ray spectral fitting on those tessellates to infer the intrinsic properties of the X-ray-emitting plasma. By modeling faint resolved point sources, we estimate the contribution to the extended X-ray emission from unresolved point sources and show that the vast majority of Carina's unresolved X-ray emission is truly diffuse. Line-like correlated residuals in the X-ray spectral fits suggest that substantial X-ray emission is generated by charge exchange at the interfaces between Carina's hot, rarefied plasma and its many cold neutral pillars, ridges, and clumps.
- ID:
- ivo://CDS.VizieR/J/A+A/643/A12
- Title:
- Cchemical abundances of 6 open cluster stars
- Short Name:
- J/A+A/643/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Open clusters are excellent tracers of the chemical evolution of the Galactic disc. The spatial distribution of their elemental abundances, through the analysis of high-quality and high-resolution spectra, provides insight into the chemical evolution and mechanisms of element nucleosynthesis in regions characterised by different conditions (e.g. star formation efficiency and metallicity). In the framework of the Stellar Population Astrophysics (SPA) project, we present new observations and spectral analysis of four sparsely studied open clusters located in the solar neighbourhood, namely Collinder 350, Gulliver 51, NGC 7044, and Ruprecht 171. We exploit the HARPS-N spectrograph at the TNG telescope to acquire high-resolution optical spectra for 15 member stars of four clusters. We derive stellar parameters (Teff, logg, [Fe/H] and {xi) using both the equivalent width (EW) analysis and the spectral fitting technique. We compute elemental abundances for light, {alpha}-, iron-peak, and n-capture elements using the EW measurement approach. We investigate the origin of the correlation between metallicity and stellar parameters derived with the EW method for the coolest stars of the sample (Teff<4300K). The correlation is likely due to the challenging continuum setting and to a general inaccuracy of model atmospheres used to reproduce the conditions of very cool giant stars. We locate the properties of our clusters in the radial distributions of metallicity and abundance ratios, comparing our results with clusters from the Gaia-ESO and APOGEE surveys. We present the [X/Fe]-[Fe/H] and [X/Fe]-RGC trends for elements in common between the two surveys. Finally, we derive the C and Li abundances as a function of the evolutionary phase and compare them with theoretical models. The SPA survey, with its high-resolution spectra, allows us to fully characterise the chemistry of nearby clusters. With a single set of spectra, we provide chemical abundances for a variety of chemical elements, which are comparable to those obtained in two of the largest surveys combined. The metallicities and abundance ratios of our clusters fit very well in the radial distributions defined by the recent literature, reinforcing the importance of star clusters to outline the spatial distribution of abundances in our Galaxy. Moreover, the abundances of C and Li, modified by stellar evolution during the giant phase, agree with evolutionary prescriptions (rotation-induced mixing) for their masses and metallicities.
- ID:
- ivo://CDS.VizieR/J/ApJ/747/102
- Title:
- ^12^C/^13^C ratio for 18 galactic R CrB stars
- Short Name:
- J/ApJ/747/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observed spectra of R Coronae Borealis (RCB) and hydrogen-deficient carbon (HdC) stars are analyzed by synthesizing the C_2_ Swan bands (1, 0), (0, 0), and (0, 1) using our detailed line list and the Uppsala model atmospheres. The (0, 1) and (0, 0) C_2_ bands are used to derive the ^12^C abundance, and the (1, 0) ^12^C^13^C band to determine the ^12^C/^13^C ratios. The carbon abundance derived from the C_2_ Swan bands is about the same for the adopted models constructed with different carbon abundances over the range 8.5 (C/He=0.1%) to 10.5 (C/He=10%). Carbon abundances derived from C I lines are about a factor of four lower than the carbon abundance of the adopted model atmosphere over the same C/He interval, as reported by Asplund et al., who dubbed the mismatch between adopted and derived C abundance as the "carbon problem." In principle, the carbon abundances obtained from C_2_ Swan bands and that assumed for the model atmosphere can be equated for a particular choice of C/He that varies from star to star. Then, the carbon problem for C_2_ bands is eliminated. However, such C/He ratios are in general less than those of the extreme helium stars, the seemingly natural relatives to the RCB and HdC stars. A more likely solution to the C_2_ carbon problem may lie in a modification of the model atmosphere's temperature structure. The derived carbon abundances and the ^12^C/^13^C ratios are discussed in light of the double degenerate and the final flash scenarios.
- ID:
- ivo://CDS.VizieR/J/ApJ/678/985
- Title:
- c2d Spitzer survey of interstellar ices. I.
- Short Name:
- J/ApJ/678/985
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low-luminosity YSOs (L~0.1-10L_{sun}_) using 3-38um Spitzer and ground-based spectra. The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra of well-studied massive YSOs (L~10^5^L_{sun}_). The long-known 6.0 and 6.85um bands are detected toward all sources, with the Class 0-type YSOs showing the deepest bands ever observed. The 6.0um band is often deeper than expected from the bending mode of pure solid H_2_O. The additional 5-7um absorption consists of five independent components, which, by comparison to laboratory studies, must be from at least eight different carriers. Much of this absorption is due to simple species likely formed by grain surface chemistry, at abundances of 1%-30% for CH_3_OH, 3%-8% for NH_3_, 1%-5% for HCOOH, ~6% for H_2_CO, and ~0.3% for HCOO- relative to solid H_2_O. The 6.85um band has one or two carriers, of which one may be less volatile than H_2_O. Its carrier(s) formed early in the molecular cloud evolution and do not survive in the diffuse ISM. If an NH_4_^+^ -containing salt is the carrier, its abundance relative to solid H_2_O is ~7%, demonstrating the efficiency of low-temperature acid-base chemistry or cosmic-ray-induced reactions. Possible origins are discussed for enigmatic, very broad absorption between 5 and 8um. Finally, the same ices are observed toward massive and low-mass YSOs, indicating that processing by internal UV radiation fields is a minor factor in their early chemical evolution.
- ID:
- ivo://CDS.VizieR/J/AJ/126/1362
- Title:
- Century Survey Galactic Halo Project. I.
- Short Name:
- J/AJ/126/1362
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Century Survey Galactic Halo Project is a photometric and spectroscopic survey from which we select relatively blue stars (V-R<0.30mag) as probes of the Milky Way halo. The survey strip spans the range of Galactic latitude 35{deg}<b<88{deg}, allowing us to study the nature of populations of stars and their systematic motions as a function of Galactic latitude. One of our primary goals is to use blue horizontal-branch stars to trace potential star streams in the halo, and to test the hierarchical model for the formation of the Galaxy. In this paper we discuss spectroscopy and multipassband photometry for a sample of 764 blue stars in the Century Survey region. Our sample consists predominantly of A- and F-type stars. We describe our techniques for determination of radial velocities, effective temperatures, metallicities, and surface gravities. Based on these measurements, we derive distance estimates by comparison with a set of calibrated isochrones. We devote special attention to the classification of blue horizontal-branch stars, and compare the results obtained from the application of the techniques of Kinman et al. 1994, Cat. <J/AJ/108/1722>, Wilhelm et al. (1999, Cat. <J/AJ/117/2308>), and Clewley et al. (2002MNRAS.337...87C). We identify 55 blue horizontal-branch stars. Our large sample of stars also uncovers a number of unusual objects, including three carbon-enhanced stars, a late B-type star located 0.8kpc above the Galactic plane, and a DZ white dwarf.