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2711. Stark broadening of XeVIII spectral lines
ID:
ivo://CDS.VizieR/J/MNRAS/454/1736
Title:
Stark broadening of XeVIII spectral lines
Short Name:
J/MNRAS/454/1736
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stark broadening parameters have been calculated for 60 spectral lines of XeVIII, for broadening by electron, proton, and HeIII impacts. For calculations, the semiclassical perturbation approach in the impact approximation has been used. The widths and shifts are provided for temperatures from 20000 K to 500000 K and for an electron density of 10^17^/cm^3^. Obtained results have been used to study the influence of Stark broadening on spectral lines in DO white dwarf atmospheres and it has been found that exist broad layers where this broadening mechanism is dominant in comparison with thermal Doppler broadening.
2712. Starless cores in CS(3-2) and DCO^+^(2-1) lines
ID:
ivo://CDS.VizieR/J/ApJS/153/523
Title:
Starless cores in CS(3-2) and DCO^+^(2-1) lines
Short Name:
J/ApJS/153/523
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present CS(3-2) and DCO^+^(2-1) observations of 94 starless cores and compare the results with previous CS(2-1) and N_2_H^+^(1-0) observations to study inward motions in starless cores. Eighty-four cores were detected in both CS and DCO^+^ lines. We identify 18 infall candidates based on observations of CS(3-2), CS(2-1), DCO^+^(2-1) and N_2_H^+^(1-0). The eight best candidates, L1355, L1498, L1521F, L1544, L158, L492, L694-2, and L1155C-1, each show at least four indications of infall asymmetry and no counterindications. Fits of the spectra to a two-layer radiative transfer model in ten infall candidates suggest that the median effective line of sight speed of the inward-moving gas is ~0.07km/s for CS(3-2) and ~0.04km/s for CS(2-1).
2713. Starless MDCs of NGC6334 molecular spectra
ID:
ivo://CDS.VizieR/J/A+A/622/A99
Title:
Starless MDCs of NGC6334 molecular spectra
Short Name:
J/A+A/622/A99
Date:
21 Oct 2021
Publisher:
CDS
Description:
The formation of high-mass stars remains unknown in many aspects. Two families of models compete to explain the formation of high-mass stars. On the one hand, quasi-static models predict the existence of high-mass pre-stellar cores sustained by a high degree of turbulence. On the other hand competitive accretion models predict that high-mass proto-stellar cores evolve from low/intermediate mass proto-stellar cores in dynamic environments. The aim of the present work is to bring observational constraints at the scale of high-mass cores (~0.03pc). We targeted with ALMA and MOPRA a sample of 9 starless massive dense cores (MDCs) discovered in a recent Herschel/HOBYS study. Their mass and size (~110M_{sun}_ and r=0.1pc, respectively) are similar to the initial conditions used in the quasi-static family of models explaining for the formation of high-mass stars.We present ALMA 1.4mm continuum observations that resolve the Jeans length ({lambda}_Jeans_~0.03pc) and that are sensitive to the Jeans mass (M_Jeans_~0.65M_{sun}_) in the 9 starless MDCs, together with ALMA-^12^CO(2-1) emission line observations. We also present HCO^+^(1-0), H^13^CO+(1-0) and N_2_H^+^(1-0) molecular lines from the MOPRA telescope for 8 of the 9 MDCs. The 9 starless MDCs have the mass reservoir to form high-mass stars according to the criteria by Baldeschi et al. (2017MNRAS.466.3682B). Three of the starless MDCs are subvirialized with {alpha}_vir_~0.35, and 4 MDCs show sign of collapse from their molecular emission lines. ALMA observations show very little fragmentation within the MDCs. Only two of the starless MDCs host compact continuum sources, whose fluxes correspond to <3M_{sun}_ fragments. Therefore the mass reservoir of the MDCs has not yet been accreted onto compact objects, and most of the emission is filtered out by the interferometer. These observations do not support the quasi-static models for high-mass star formation since no high-mass pre-stellar core is found in NGC6334. The competitive accretion models, on the other hand, predict a level of fragmentation much higher than what we observe
2714. Stars and globulars in NGC4494
ID:
ivo://CDS.VizieR/J/MNRAS/415/3393
Title:
Stars and globulars in NGC4494
Short Name:
J/MNRAS/415/3393
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a comprehensive analysis of the spatial, kinematic and chemical properties of stars and globular clusters (GCs) in the 'ordinary' elliptical galaxy NGC 4494 using data from the Keck and Subaru telescopes. We derive galaxy surface brightness and colour profiles out to large galactocentric radii. We compare the latter to metallicities derived using the near-infrared Calcium Triplet. We obtain stellar kinematics out to ~3.5 effective radii.
2715. Stars classified from S2/68 UV line features
ID:
ivo://CDS.VizieR/III/53
Title:
Stars classified from S2/68 UV line features
Short Name:
III/53
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog provides the spectral classifications of 1900 stars from the papers listed in References. The classifications were made from spectra obtained by the S2/68 sky survey telescope experiment aboard the TD1 satellite.
2716. Stars in the Carina dSph galaxy field
ID:
ivo://CDS.VizieR/J/AJ/130/2677
Title:
Stars in the Carina dSph galaxy field
Short Name:
J/AJ/130/2677
Date:
21 Oct 2021
Publisher:
CDS
Description:
The question of the existence of active and prominent tidal disruption around various Galactic dwarf spheroidal (dSph) galaxies remains controversial. That debate often centers on the nature (bound vs. unbound) of extended populations of stars claimed to lie outside the bounds of single King profiles fitted to the density distributions of dSph centers. However, the more fundamental issue of the very existence of the previously reported extended populations is still contentious. We present a critical evaluation of the debate centering on one particular dSph, Carina, for which claims both for and against the existence of stars beyond the King limiting radius have been made.
2717. Stars of very low metal abundance. I
ID:
ivo://CDS.VizieR/J/AJ/90/2089
Title:
Stars of very low metal abundance. I
Short Name:
J/AJ/90/2089
Date:
21 Oct 2021
Publisher:
CDS
Description:
An objective-prism and a narrowband interference filter have been used in combination on the Curtis Schmidt telescope at CTIO to conduct a search for extremely metal-poor stars. The filter restricts the bandpass to the region around the H and K lines of CaII; the metal-poor candidates are those stars with weak or absent H and K. Slit spectra (1 A resolution) of some 450 candidates are used to measure equivalent widths of the CaII K line and Balmer features. A calibration of the K-line strength for giants in the metal-poor globular cluster NGC 6397 and field dwarfs and giants of known metallicity is used to identify survey candidates with metal abundance [Fe/H]<=-2.0; a list of 134 such stars is presented. UBV photometry is used to distinguish between two groups of metal-poor stars: a group with objects near the main-sequence turnoff, on the subgiant branch, and on the giant branch; and a second group with objects on the red horizontal branch (RHB) and asymptotic giant branch (AGB). The RHB-AGB stars exhibit the well-known weak G-band effect; three CH-strong objects are identified among the subgiants.
2718. Statistical properties of exoplanets II
ID:
ivo://CDS.VizieR/J/A+A/398/363
Title:
Statistical properties of exoplanets II
Short Name:
J/A+A/398/363
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table2 file is an extended version of table 2 in the paper. It contains the stellar parameters as well as the number of FeI and FeII lines used (and the rms around the mean value) in the analysis, the spectrograph used, and the derived stellar masses for each star. Velocity files contains the U, V, and W space velocities for the planet host stars used in Figs. 9 and 10.
2719. STELIB: A library of stellar spectra at R~2000
ID:
ivo://CDS.VizieR/III/232
Title:
STELIB: A library of stellar spectra at R~2000
Short Name:
III/232
Date:
21 Oct 2021
Publisher:
CDS
Description:
STELIB is a new spectroscopic stellar library, available at http://webast.ast.obs-mip.fr/stelib . It consists in an homogeneous library of stellar spectra in the visible range (3200 to 9500){AA}), with an intermediate spectral resolution (<~3{AA}) and sampling (1{AA}), and corrected from interstellar absorption. This library includes 255 stars of various spectral types and luminosity classes, spanning a relatively wide range in metallicity. The spectral resolution, wavelength and spectral type coverage of this library represents a substantial improvement over previous libraries used in population synthesis models. The overall absolute photometric uncertainty is 3%. The data were obtained during two runs, one at the 1m Jacobus Kaptein Telescope (JKT), Roque de los Muchachos Observatory, La Palma, Canary Islands, Spain, between 1994 March 28 and April 4, and a second one at the 2.3m of the Australian National University at Siding Spring (SSO), Australia, between 1994 December 25 and 31.
2720. Stellar abundances from LAMOST MRS (SPCAnet)
ID:
ivo://CDS.VizieR/J/ApJ/891/23
Title:
Stellar abundances from LAMOST MRS (SPCAnet)
Short Name:
J/ApJ/891/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
The fundamental stellar atmospheric parameters (Teff and logg) and 13 chemical abundances are derived for medium-resolution spectroscopy from Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Medium Resolution Survey (MRS) data sets with a deep-learning method. The neural networks we designed, named SPCANet, precisely map LAMOST MRS spectra to stellar parameters and chemical abundances. The stellar labels derived by SPCANet have precisions of 119K for Teff and 0.17dex for logg. The abundance precision of 11 elements including [C/H], [N/H], [O/H], [Mg/H], [Al/H], [Si/H], [S/H], [Ca/H], [Ti/H], [Cr/H], [Fe/H], and [Ni/H] are 0.06 {\sim} 0.12 dex, while that of [Cu/H] is 0.19dex. These precisions can be reached even for spectra with signal-to-noise ratios as low as 10. The results of SPCANet are consistent with those from other surveys such as APOGEE, GALAH, and RAVE, and are also validated with the previous literature values including clusters and field stars.

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