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1411. Line list for seven target PAndAS clusters
ID:
ivo://CDS.VizieR/J/MNRAS/448/1314
Title:
Line list for seven target PAndAS clusters
Short Name:
J/MNRAS/448/1314
Date:
21 Oct 2021
Publisher:
CDS
Description:
Detailed chemical abundances are presented for seven M31 outer halo globular clusters (with projected distances from M31 greater than 30 kpc), as derived from high-resolution integrated light spectra taken with the Hobby-Eberly Telescope. Five of these clusters were recently discovered in the Pan-Andromeda Archaeological Survey (PAndAS) - this paper presents the first determinations of integrated Fe, Na, Mg, Ca, Ti, Ni, Ba, and Eu abundances for these clusters. Four of the target clusters (PA06, PA53, PA54, and PA56) are metal poor ([Fe/H]< -1.5), {alpha}-enhanced (though they are possibly less {alpha}-enhanced than Milky Way stars at the 1{sigma} level), and show signs of star-to-star Na and Mg variations. The other three globular clusters (H10, H23, and PA17) are more metal rich, with metallicities ranging from [Fe/H]=-1.4 to -0.9. While H23 is chemically similar to Milky Way field stars, Milky Way globular clusters, and other M31 clusters, H10 and PA17, have moderately low [Ca/Fe], compared to Milky Way field stars and clusters. Additionally, PA17's high [Mg/Ca] and [Ba/Eu] ratios are distinct from Milky Way stars, and are in better agreement with the stars and clusters in the Large Magellanic Cloud. None of the clusters studied here can be conclusively linked to any of the identified streams from PAndAS; however, based on their locations, kinematics, metallicities, and detailed abundances, the most metal-rich PAndAS clusters H23 and PA17 may be associated with the progenitor of the Giant Stellar Stream, H10 may be associated with the SW cloud, and PA53 and PA56 may be associated with the eastern cloud.
1412. Line list for the NGC 1851 stars
ID:
ivo://CDS.VizieR/J/MNRAS/446/3319
Title:
Line list for the NGC 1851 stars
Short Name:
J/MNRAS/446/3319
Date:
21 Oct 2021
Publisher:
CDS
Description:
We measure the C+N+O abundance sum in red giant stars in two Galactic globular clusters, NGC 1851 and NGC 6752. NGC 1851 has a split subgiant branch which could be due to different ages or C+N+O content while NGC 6752 is representative of the least complex globular clusters. For NGC 1851 and NGC 6752, we obtain average values of A(C+N+O)=8.16+/-0.10 ({sigma}=0.34) and 7.62+/-0.02 ({sigma}=0.06), respectively. When taking into account the measurement errors, we find a constant C+N+O abundance sum in NGC 6752. The C+N+O abundance dispersion is only 0.06 dex, and such a result requires that the source of the light element abundance variations does not increase the C+N+O sum in this cluster. For NGC 1851, we confirm a large spread in C+N+O. In this cluster, the anomalous RGB has a higher C+N+O content than the canonical RGB by a factor of 4 (~0.6 dex). This result lends further support to the idea that the two subgiant branches in NGC 1851 are roughly coeval, but with different CNO abundances.
1413. Linelist of 14 Galactic post-AGB stars
ID:
ivo://CDS.VizieR/J/A+A/587/A6
Title:
Linelist of 14 Galactic post-AGB stars
Short Name:
J/A+A/587/A6
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper is part of a larger project in which we systematically study the chemical abundances of Galactic and extragalactic post-asymptotic giant branch (post-AGB) stars. The goal at large is to provide improved observational constraints to the models of the complex interplay between the AGB s-process nucleosynthesis and the associated mixing processes. Aims. Lead (Pb) is the final product of the s-process nucleosynthesis and is predicted to have large overabundances with respect to other s-process elements in AGB stars of low metallicities. However, Pb abundance studies of s-process enriched post-AGB stars in the Magellanic Clouds show a discrepancy between observed and predicted Pb abundances. The determined upper limits based on spectral studies are much lower than what is predicted. In this paper, we focus specifically on the Pb abundance of 14 Galactic s-process enhanced post-AGB stars to check whether the same discrepancy is present in the Galaxy as well. Among these 14 objects, two were not yet subject to a detailed abundance study in the literature. We apply the same method to obtain accurate abundances for the 12 others. Our homogeneous abundance results provide the input of detailed spectral synthesis computations in the spectral regions where Pb lines are located. We used high-resolution UVES and HERMES spectra for detailed spectral abundance studies of our sample of Galactic post-AGB stars. None of the sample stars display clear Pb lines, and we only deduced upper limits of the Pb abundance by using spectrum synthesis in the spectral ranges of the strongest Pb lines.
1414. Line lists
ID:
ivo://CDS.VizieR/J/MNRAS/447/492
Title:
Line lists
Short Name:
J/MNRAS/447/492
Date:
21 Oct 2021
Publisher:
CDS
Description:
Knowledge of the elemental abundances of symbiotic giants is essential to address the role of chemical composition in the evolution of symbiotic binaries, to map their parent population, and to trace their mass transfer history. However, there are few symbiotic giants for which the photospheric abundances are fairly well determined. This is the second in a series of papers on chemical composition of symbiotic giants determined from high-resolution (R~50000) near-IR spectra. Results are presented for the late-type giant star in the AE Ara, BX Mon, KX TrA, and CL Sco systems. Spectrum synthesis employing standard local thermal equilibrium (LTE) analysis and stellar atmosphere models were used to obtain photospheric abundances of CNO and elements around the iron peak (Sc, Ti, Fe, and Ni). Our analysis resulted in sub-solar metallicities in BX Mon, KX TrA, and CL Sco by [Fe/H]~-0.3 or -0.5 depending on the value of microturbulence. AE Ara shows metallicity closer to solar by ~0.2 dex. The enrichment in ^14^N isotope found in all these objects indicates that the giants have experienced the first dredge-up. In the case of BX Mon first dredge-up is also confirmed by the low ^12^C/^13^C isotopic ratio of ~8.
1415. Linelists for C3H- from CALPGM
ID:
ivo://CDS.VizieR/J/ApJ/783/36
Title:
Linelists for C3H- from CALPGM
Short Name:
J/ApJ/783/36
Date:
21 Oct 2021
Publisher:
CDS
Description:
Pety et al. have reported the detection of eight transitions of a closed-shell, linear molecule (B11244) in observations toward the Horsehead photodissociation region (PDR), which they attribute to the l-C_3_H^+^ cation. Recent high-level ab initio calculations have called this assignment into question; the anionic C_3_H^-^ molecule has been suggested as a more likely candidate. Here, we examine observations of the Horsehead PDR, Sgr B2(N), TMC-1, and IRC+10216 in the context of both l-C_3_H^+^ and C_3_H^-^. We find no observational evidence of K_a_=1 lines, which should be present were the carrier indeed C_3_H^-^. Additionally, we find a strong anticorrelation between the presence of known molecular anions and B11244 in these regions. Finally, we discuss the formation and destruction chemistry of C_3_H^-^ in the context of the physical conditions in the regions. Based on these results, we conclude there is little evidence to support the claim that the carrier is C_3_H^-^.
1416. Line positions for TiO singlet states
ID:
ivo://CDS.VizieR/J/ApJS/236/46
Title:
Line positions for TiO singlet states
Short Name:
J/ApJS/236/46
Date:
21 Oct 2021
Publisher:
CDS
Description:
A consistent set of spectroscopic constants for the a^1^{Delta}, d^1^{Sigma}^+^, b^1^{Pi}, c^1^{Phi}, and f^1^{Delta} states of ^48^Ti^16^O has been determined from analysis of the b^1^{Pi}-a^1^{Delta}, b^1^{Pi}-d^1^{Sigma}^+^, c^1^{Phi}-a^1^{Delta}, and f^1^{Delta}-a^1^{Delta} systems. Three Fourier transform emission spectra have been used for the analysis. New bands of the b^1^{Pi}-a^1^{Delta} and c^1^{Phi}-a^1^{Delta} systems have been fitted. The first analysis of the c^1^{Phi}-a^1^{Delta} system using Fourier transform spectra is also provided. Extensive and improved line positions are measured. TiO is prominent in the spectra of oxygen-rich cool stellar objects and may be present in hot-Jupiter exoplanet atmospheres.
1417. Line ratios in giant HII region H 1013
ID:
ivo://CDS.VizieR/J/A+A/551/A82
Title:
Line ratios in giant HII region H 1013
Short Name:
J/A+A/551/A82
Date:
21 Oct 2021
Publisher:
CDS
Description:
While collisionally excited lines in HII regions allow one to easily probe the chemical composition of the interstellar medium in galaxies, the possible presence of important temperature fluctuations casts some doubt on the derived abundances. To provide new insights into this question, we have carried out a detailed study of a giant HII region, H1013, located in the galaxy M101, for which many observational data exist and which has been claimed to harbour temperature temperature fluctuations at a level of t^2^=0.03-0.06.
1418. Line ratios in z~2-3 galaxies from KBSS-MOSFIRE
ID:
ivo://CDS.VizieR/J/ApJ/795/165
Title:
Line ratios in z~2-3 galaxies from KBSS-MOSFIRE
Short Name:
J/ApJ/795/165
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present initial results of a deep near-IR spectroscopic survey covering the 15 fields of the Keck Baryonic Structure Survey using the recently commissioned MOSFIRE spectrometer on the Keck 1 telescope. We focus on a sample of 251 galaxies with redshifts 2.0<z<2.6, star formation rates (SFRs) 2<~SFR<~200 M_{sun}_/yr, and stellar masses 8.6<log(M_*_/M_{sun}_)<11.4, with high-quality spectra in both H- and K-band atmospheric windows. We show unambiguously that the locus of z~2.3 galaxies in the "BPT" nebular diagnostic diagram exhibits an almost entirely disjointed, yet similarly tight, relationship between the line ratios [N II] {lambda}6585/H{alpha} and [O III]/H{beta} as compared to local galaxies. Using photoionization models, we argue that the offset of the z~2.3 BPT locus relative to that at z~0 is caused by a combination of harder stellar ionizing radiation field, higher ionization parameter, and higher N/O at a given O/H compared to most local galaxies, and that the position of a galaxy along the z~2.3 star-forming BPT locus is surprisingly insensitive to gas-phase oxygen abundance. The observed nebular emission line ratios are most easily reproduced by models in which the net stellar ionizing radiation field resembles a blackbody with effective temperature T_eff_=50000-60000 K, the gas-phase oxygen abundances lie in the range 0.2<Z/Z_{sun}_<1.0, and the ratio of gas-phase N/O is close to the solar value. We critically assess the applicability at high redshift of commonly used strong line indices for estimating gas-phase metallicity, and consider the implications of the small intrinsic scatter of the empirical relationship between excitation-sensitive line indices and M_*_(i.e., the "mass-metallicity" relation) at z=~2.3.
1419. Lines and continuum sky emission in the NIR
ID:
ivo://CDS.VizieR/J/A+A/581/A47
Title:
Lines and continuum sky emission in the NIR
Short Name:
J/A+A/581/A47
Date:
21 Oct 2021
Publisher:
CDS
Description:
Determining the intensity of lines and continuum airglow emission in the H-band is important for the design of faint-object infrared spectrographs. Existing spectra at low/medium resolution cannot disentangle the true sky-continuum from instrumental effects (e.g. diffuse light in the wings of strong lines). We aim to obtain, for the first time, a high resolution infrared spectrum deep enough to set significant constraints on the continuum emission between the lines in the H-band. During the second commissioning run of the GIANO high-resolution spectrograph at the La Palma Observatory, we pointed the instrument directly to the sky and obtained a deep spectrum that extends from 0.97 to 2.4 micron and includes the whole H-band. The spectrum shows about 1500 emission lines, a factor of two more than in previous works. Of these, 80% are identified as OH transitions; half of these are from highly excited molecules (hot-OH component). The other lines are attributable to O_2_ or unidentified. Several of the faint lines are in spectral regions that were previously believed to be free of lines emission. The continuum in the H-band is marginally detected at a level of about 300photons/m^2^/s/arcsec^2^/um. The observed spectrum and the list of observed sky-lines are published in electronic format. Our measurements indicate that the sky continuum in the H-band could be even darker than previously believed. However, the myriad of airglow emission lines severely limits the spectral ranges where very low background can be effectively achieved with low/medium resolution spectrographs. We identify a few spectral bands that could still remain quite dark at the resolving power foreseen for VLT-MOONS (R~6,600).
1420. Lines in the infrared solar spectrum
ID:
ivo://CDS.VizieR/J/A+AS/113/71
Title:
Lines in the infrared solar spectrum
Short Name:
J/A+AS/113/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
We list 603 spectral lines between 1.0, 1.8um that are judged to be relatively unblended from a visual inspection of spectra of the quiet sun. Much of the atomic data of relevance to studies of solar and stellar magnetism, convection and atmospheric structure are also provided. Particular attention is paid to blending by telluric lines. We determine the level of blending both in the presence and the absence of telluric lines. We also describe how telluric blends may be removed from spectra with high spectral resolution.

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