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71. Absorption-line systems in QSO spectra - CoALS
ID:
ivo://CDS.VizieR/J/A+A/412/707
Title:
Absorption-line systems in QSO spectra - CoALS
Short Name:
J/A+A/412/707
Date:
21 Oct 2021
Publisher:
CDS
Description:
Absorption lines and absorption-line systems (ALSs) observed in the spectra of QSOs contain fundamental information on distribution of matter between the observer and the QSO, and on physical processes in the Universe in different epochs of the cosmological evolution. The presented catalog contains a compilation of basic information on absorption-line systems (ALSs) in QSO spectra. The data are taken from publications available to the authors up to January 2002. The catalog includes, in particular, all the data of the catalogs by Junkkarinen et al. (1991ApJS...77..203J) and York et al. (1991MNRAS.250...24Y ). The catalog consists of table1.dat, table2.txt and the list of references in refs.dat file. The present catalog is also available at the site of the Dept. of Theor. Astrophys. of the Ioffe Physical Technical Institute: <www.ioffe.ru/astro/QC>
72. Absorption velocities for 21 super-luminous SNe Ic
ID:
ivo://CDS.VizieR/J/ApJ/845/85
Title:
Absorption velocities for 21 super-luminous SNe Ic
Short Name:
J/ApJ/845/85
Date:
21 Oct 2021
Publisher:
CDS
Description:
Super-luminous supernovae (SLSNe) are tremendously luminous explosions whose power sources and progenitors are highly debated. Broad-lined SNe Ic (SNe Ic-bl) are the only type of SNe that are connected with long-duration gamma-ray bursts (GRBs). Studying the spectral similarity and difference between the populations of hydrogen-poor SLSNe (SLSNe Ic) and of hydrogen-poor stripped-envelope core-collapse SNe, in particular SNe Ic and SNe Ic-bl, can provide crucial observations to test predictions of theories based on various power source models and progenitor models. In this paper, we collected all of the published optical spectra of 32 SLSNe Ic, 21 SNe Ic-bl, as well as 17 SNe Ic, quantified their spectral features, constructed average spectra, and compared them in a systematic way using new tools we have developed. We find that SLSNe Ic and SNe Ic-bl, including those connected with GRBs, have comparable widths for their spectral features and average absorption velocities at all phases. Thus, our findings strengthen the connection between SLSNe Ic and GRBs. In particular, SLSNe Ic have average FeII{lambda}5169 absorption velocities of -15000+/-2600km/s at 10 days after peak, which are higher than those of SNe Ic by ~7000km/s on average. SLSNe Ic also have significantly broader FeII{lambda}5169 lines than SNe Ic. Moreover, we find that such high absorption and width velocities of SLSNe Ic may be hard to explain with the interaction model, and none of the 13 SLSNe Ic with measured absorption velocities spanning over 10 days has a convincing flat velocity evolution, which is inconsistent with the magnetar model in one dimension. Lastly, we compare SN 2011kl, the first SN connected with an ultra-long GRB, with the mean spectrum of SLSNe Ic and of SNe Ic-bl.
73. AB-type RR Lyrae stars from ASAS and WASP
ID:
ivo://CDS.VizieR/J/MNRAS/445/1584
Title:
AB-type RR Lyrae stars from ASAS and WASP
Short Name:
J/MNRAS/445/1584
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this article, we present results based on high-density, high-precision Wide-Angle Search for Planets (WASP) light curves supplemented with lower-precision photometry from the All-Sky Automated Survey (ASAS) for 268 RR Lyrae stars (176 regular, 92 Blazhko). Light curves were Fourier-decomposed and coefficients from WASP were transformed to the ASAS standard using 24 common stars. Coefficients were then compared with similar data from Galactic globular clusters, the Galactic bulge and the Large and Small Magellanic Clouds (LMC and SMC). Using Fourier coefficients, we also calculated physical parameters via standard equations from the literature. We confirmed the results of previous authors, including lower amplitudes and longer rise times for Blazhko stars. It was found that in the R_31_ versus R_21_ plot the location of a star depends mainly on its metallicity and that Blazhko stars prefer a different location from modulation-free stars. Field and globular cluster RR Lyrae variables have a different {phi}21 and {phi}31 from stars in the LMC, SMC and Galactic bulge. Although there are some weak indications that Blazhko stars could tend towards a slightly lower metallicity and shorter periods, no convincing proof was found. The most interesting highlight is the identification of a very recently proposed new group of metal-rich RR Lyrae type stars. These low-luminosity, metal-strong variables, comprising both Blazhko and regular stars, have shorter periods and about 180K higher temperature at constant (B-V)_0_ than the rest of the stars in the sample.
74. Abunbances of 9 red giants of Pal 14
ID:
ivo://CDS.VizieR/J/A+A/537/A83
Title:
Abunbances of 9 red giants of Pal 14
Short Name:
J/A+A/537/A83
Date:
21 Oct 2021
Publisher:
CDS
Description:
Chemical abundances of 25 elements, which include {alpha}-, iron peak-, and neutron-capture elements, in the outer halo globular cluster Palomar 14 have been determined for the nine red giants observed with the FLAMES/UVES spectrograph. The abundance pattern of Pal 14 is similar to the inner halo GCs, halo field stars, and GCs of recognized extragalactic origin, but differs from what is customarily found in dSphs field stars. The abundance properties of Pal 14 as well as those of the other outer halo GCs are thus compatible with an accretion origin from dSphs. The neutron-capture elements show an r-process signature.
75. Abundance-age relations with open clusters
ID:
ivo://CDS.VizieR/J/A+A/652/A25
Title:
Abundance-age relations with open clusters
Short Name:
J/A+A/652/A25
Date:
22 Feb 2022
Publisher:
CDS
Description:
Precise chemical abundances coupled with reliable ages are key ingredients to understand the chemical history of our Galaxy. Open Clusters (OCs) are useful for this purpose because they provide ages with good precision. The aim of this work is to investigate the relations of different chemical abundance ratios vs age traced by red clump (RC) stars in OCs. We analyze a large sample of "NGoodstars" reliable members in "NClusters" OCs with available high-resolution spectroscopy. We applied a differential line-by-line analysis to provide a comprehensive chemical study of "NElements" chemical species. This sample is among the largest samples of OCs homogeneously characterized in terms of atmospheric parameters, detailed chemistry, and ages. In our metallicity range (-0.2<[M/H]<+0.2) we find that while most Fe-peak and {alpha} elements have flat dependence with age, the s-process elements show decreasing trends with increasing age with a remarkable knee at 1Gyr. For Ba, Ce, Y, Mo and Zr we find a plateau at young ages (<1Gyr). We investigate the relations of all possible combinations among the computed chemical species with age. We find 19 combinations with significant slopes, including [Y/Mg] and [Y/Al]. The ratio [Ba/{alpha}] is the one with the most significant correlations found. We find that the [Y/Mg] relation found in the literature using Solar twins is compatible with the one found here in the Solar neighbourhood. The age-abundance relations show larger scatter for clusters at large distances (d>1kpc) than for the Solar neighbourhood, particularly in the outer disk. We conclude that these relations need to be understood also in terms of the complexity of the chemical space introduced by the Galactic dynamics, on top of pure nucleosynthetic arguments, especially out of the local bubble.
76. Abundance analysis of 4 red giants in NGC 6558
ID:
ivo://CDS.VizieR/J/A+A/619/A178
Title:
Abundance analysis of 4 red giants in NGC 6558
Short Name:
J/A+A/619/A178
Date:
21 Oct 2021
Publisher:
CDS
Description:
NGC 6558 is a bulge globular cluster with a blue horizontal branch (BHB), combined with a metallicity of [Fe/H]~-1.0. It is similar to HP 1 and NGC 6522, which could be among the oldest objects in the Galaxy. Element abundances in these clusters could reveal the nature of the first supernovae. We aim to carry out detailed spectroscopic analysis for four red giants of NGC 6558, in order to derive the abundances of the light elements C, N, O, Na, Al, the {alpha}-elements Mg, Si, Ca, Ti, and the heavy elements Y, Ba, and Eu. High-resolution spectra of four stars with FLAMES-UVES@VLT UT2-Kueyen were analysed. Spectroscopic parameter-derivation was based on excitation and ionization equilibrium of FeI and FeII. This analysis results in a metallicity of [Fe/H]=-1.17+/-0.10 for NGC 6558. We find the expected {alpha}-element enhancements in O and Mg with [O/Fe]=+0.40, [Mg/Fe]=+0.33, and low enhancements in Si and Ca. Ti has a moderate enhancement of [Ti/Fe]=+0.22. The r-element Eu appears very enhanced with a mean value of [Eu/Fe]=+0.63. The first peak s-elements Y and Sr are also enhanced, these results have however to be treated with caution, given the uncertainties in the continuum definition; the use of neutral species (Sr I, YI), instead of the dominant ionized species is another source of uncertainty. Ba appears to have a solar abundance ratio relative to Fe. NGC 6558 shows an abundance pattern that could be typical of the oldest inner bulge globular clusters, together with the pattern in the similar clusters NGC 6522 and HP 1. They show low abundances of the odd-Z elements Na and Al, and of the explosive nucleosynthesis {alpha}-elements Si, Ca, and Ti. The hydrostatic burning {alpha}-elements O and Mg are normally enhanced as expected in old stars enriched with yields from core-collapse supernovae, and the iron-peak elements Mn, Cu, Zn show low abundances, which is expected forMn and Cu, but not for Zn. Finally, the cluster trio NGC 6558, NGC 6522 and HP 1 have relatively high abundances of first-peak heavy elements, variable second-peak element Ba, and the r-element Eu is enhanced. The latter is particularly high in NGC 6558.
77. Abundance analysis of 9 very metal-poor stars
ID:
ivo://CDS.VizieR/J/ApJ/838/90
Title:
Abundance analysis of 9 very metal-poor stars
Short Name:
J/ApJ/838/90
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have performed a differential line-by-line chemical abundance analysis, ultimately relative to the Sun, of nine very metal-poor main-sequence (MS) halo stars, near [Fe/H]=-2dex. Our abundances range from -2.66<=[Fe/H]<=-1.40dex with conservative uncertainties of 0.07dex. We find an average [{alpha}/Fe]=0.34+/-0.09dex, typical of the Milky Way. While our spectroscopic atmosphere parameters provide good agreement with Hubble Space Telescope parallaxes, there is significant disagreement with temperature and gravity parameters indicated by observed colors and theoretical isochrones. Although a systematic underestimate of the stellar temperature by a few hundred degrees could explain this difference, it is not supported by current effective temperature studies and would create large uncertainties in the abundance determinations. Both 1D and <3D> hydrodynamical models combined with separate 1D non-LTE effects do not yet account for the atmospheres of real metal-poor MS stars, but a fully 3D non-LTE treatment may be able to explain the ionization imbalance found in this work.
78. Abundance distribution of stars with planets
ID:
ivo://CDS.VizieR/J/MNRAS/370/163
Title:
Abundance distribution of stars with planets
Short Name:
J/MNRAS/370/163
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a uniform, high-precision spectroscopic metallicity study of 136 G-type stars from the Anglo-Australian Planet Search, 20 of which are known to harbour extrasolar planets (as at 2005 July). Abundances in Fe, C, Na, Al, Si, Ca, Ti and Ni are presented, along with Stroemgen photometric metallicities. This study is one of several recent studies examining the metallicities of a sample of planet-host and non-planet-host stars that were obtained from a single sample, and analysed in an identical manner, providing an unbiased estimate of the metallicity trends for planet-bearing stars. We find that non-parametric tests of the distribution of metallicities for planet-host and non-planet-host stars are significantly different at a level of 99.4 per cent confidence. We confirm the previously observed trend for planet-host stars to have higher mean metallicities than non-planet-host stars, with a mean metallicity for planet-host stars of [Fe/H]=0.06+/-0.03dex compared with [Fe/H]=0.09+/-0.01dex for non-host-stars in our sample. This enrichment is also seen in the other elements studied. Based on our findings, we suggest that this observed enhancement is more likely a relic of the original gas cloud from which the star and its planets formed, rather than being due to 'pollution' of the stellar photosphere.
79. Abundance gradients from disk PNs
ID:
ivo://CDS.VizieR/J/A+A/282/436
Title:
Abundance gradients from disk PNs
Short Name:
J/A+A/282/436
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new determination of the radial abundance gradients of O/H, Ne/H, S/H, and Ar/H is made for disk planetary nebulae, (PN), that is, those objects of Peimbert types I, II, and III. On the basis of a sample containing 200 nebulae, it can be concluded that these gradients are generally similar, and of the same order of magnitude as the O/H gradient displayed by galactic HII regions. Some distance-independent correlations confirm the accuracy of the abundances and support the interpretation of the gradients in terms of chemical evolution models. The time evolution of the abundance gradients in the Milky Way is investigated, and their variation with the types of PN are compared with predictions of chemical evolution models.
80. Abundance gradients in low SB spirals
ID:
ivo://CDS.VizieR/J/MNRAS/454/3664
Title:
Abundance gradients in low SB spirals
Short Name:
J/MNRAS/454/3664
Date:
21 Oct 2021
Publisher:
CDS
Description:
We acquired spectra of 141 HII regions in 10 late-type low surface brightness galaxies (LSBGs). The analysis of the chemical abundances obtained from the nebular emission lines shows that metallicity gradients are a common feature of LSBGs, contrary to previous claims concerning the absence of such gradients in this class of galaxies. The average slope, when expressed in units of the isophotal radius, is found to be significantly shallower in comparison to galaxies of high surface brightness. This result can be attributed to the reduced surface brightness range measured across their discs, when combined with a universal surface mass density-metallicity relation. With a similar argument we explain the common abundance gradient observed in high surface brightness galaxy (HSBG) discs and its approximate dispersion. This conclusion is reinforced by our result that LSBGs share the same common abundance gradient with HSBGs, when the slope is expressed in terms of the exponential disc scalelength.

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