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1. The Gaia-ESO Survey: A simple explanation for the Li-rich giant problem

Author

Casey, Andrew R., Ruchti, G., Masseron, T., Randich, S., Gilmore, G., Lind, K., Grant Kennedy, Smiljanic, R., Jofre, P., Hourihane, A., Bragaglia, A., Donati, P., Koposov, S. E., Worley, C. C., Lanzafame, A., Franciosini, E., Lewis, J. R., Magrini, L., Morbidelli, L., Sacco, G. G., Bensby, T., Carraro, G., Damiani, F., Feltzing, S., Jeffries, R. D., Korn, A. J., Lardo, C., Laverny, P., Delgado Mena, E., Costado, M. T., Flaccomio, E., Frasca, A., Monaco, L., Pancino, E., Prisinzano, L., Recio-Blanco, A., Sbordone, L., Sousa, S. G., Tautvaisiene, G., Vallenari, A., Zaggia, S., Zwitter, T., Silva Aguirre, V., Chorniy, Y., Martell, S. L., Miglo, A., Chiappini, C., Montalban, J., Morel, T., and Valentini, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The discovery of lithium-rich giants contradicts expectations from canonical stellar evolution. Although multiple scenarios have been proposed to preserve or produce Li, no model can explain the ensemble properties of Li-rich giants. We report on the serendipitous discovery of 20 Li-rich giants observed through the Gaia-ESO Survey. Our sample is one of the largest in the literature, and includes nine towards the CoRoT fields. We explore all mechanisms proposed to explain Li-rich giants. While the planet accretion scenario was presented to reconcile observations of Li-rich giants across the RGB/AGB, this is inconsistent with recent studies of close-in giant planets. We highlight recent observations of the difference in hot Jupiter occurrence rates around dwarf and sub-giant stars as evidence for their tidal destruction when the convective envelope expands. Therefore any close-in giant planet is likely to be engulfed well before the host evolves up the RGB/AGB. When this occurs, simulations indicate a giant planet will provide a small reservoir of unburnt Li to replenish the stellar photospheric abundance, and subsequently induce deep mixing to produce additional Li. We argue these two independent lines of evidence actually predict the existence of Li-rich giants, and suggests they should be preferentially found before the luminosity bump at near-solar metallicities, consistent with observations. This scenario explains (indeed, predicts) the majority properties of Li-rich giants, leaving a minority population of evolved metal-poor Li-rich giants which are explainable by internal mixing processes associated with late evolutionary stages, or mass transfer from more evolved AGB stars.

Published
2016
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2. Cannibals in the thick disk: the young $��-$rich stars as evolved blue stragglers

Author

Jofre, P., Jorissen, A., Van Eck, S., Izzard, R. G., Masseron, T., Hawkins, K., Gilmore, G., Paladini, C., Escorza, A., Blanco-Cuaresma, S., and Manick, R.

Subjects
Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

Spectro-seismic measurements of red giants enabled the recent discovery of stars in the thick disk that are more massive than 1.4 M_sun. While it has been claimed that most of these stars are younger than the rest of the typical thick disk stars, we show evidence that they might be products of mass transfer in binary evolution, notably evolved blue stragglers. We took new measurements of the radial velocities in a sample of 26 stars from APOKASC, including 13 "young" stars and 13 "old" stars with similar stellar parameters but with masses below 1.2 M_sun and found that more of the "young" stars appear to be in binary systems with respect to the "old" stars. Furthermore, we show that the "young" stars do not follow the expected trend of [C/H] ratios versus mass for individual stars. However, with a population synthesis of low-mass stars including binary evolution and mass transfer, we can reproduce the observed [C/N] ratios versus mass. Our study shows how asteroseismology of solar-type red giants provides us with a unique opportunity to study the evolution of field blue stragglers after they have left the main-sequence., to be published in A&A after new RV measurements during 2016

Published
2016
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3. The Gaia-ESO Survey: processing of the FLAMES-UVES spectra

Author

Sacco, G. G., Morbidelli, L., Franciosini, E., Maiorca, E., Randich, S., Modigliani, A., Gilmore, G., Asplund, M., Binney, J., Bonifacio, P., Drew, J., Feltzing, S., Ferguson, A., Jeffries, R., Micela, G., Negueruela, I., Prusti, T., Rix, H. -W., Vallenari, A., Alfaro, E., Prieto, C. Allende, Babusiaux, C., Bensby, T., Blomme, R., Bragaglia, A., Flaccomio, E., Francois, P., Hambly, N., Irwin, M., Koposov, S., Korn, A., Lanzafame, A., Pancino, E., Recio-Blanco, A., Smiljanic, R., Van Eck, S., Walton, N., Bergemann, M., Costado, M. T., de Laverny, P., Heiter, U., Hill, V., Hourihane, A., Jackson, R., Jofre, P., Lewis, J., Lind, K., Lardo, C., Magrini, L., Masseron, T., Prisinzano, L., and Worley, C.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Astrophysics of Galaxies, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

The Gaia-ESO Survey is a large public spectroscopic survey that aims to derive radial velocities and fundamental parameters of about 10^5 Milky Way stars in the field and in clusters. Observations are carried out with the multi-object optical spectrograph FLAMES, using simultaneously the medium resolution (R~20,000) GIRAFFE spectrograph and the high resolution (R~47,000) UVES spectrograph. In this paper, we describe the methods and the software used for the data reduction, the derivation of the radial velocities, and the quality control of the FLAMES-UVES spectra. Data reduction has been performed using a workflow specifically developed for this project. This workflow runs the ESO public pipeline optimizing the data reduction for the Gaia-ESO Survey, performs automatically sky subtraction, barycentric correction and normalisation, and calculates radial velocities and a first guess of the rotational velocities. The quality control is performed using the output parameters from the ESO pipeline, by a visual inspection of the spectra and by the analysis of the signal-to-noise ratio of the spectra. Using the observations of the first 18 months, specifically targets observed multiple times at different epochs, stars observed with both GIRAFFE and UVES, and observations of radial velocity standards, we estimated the precision and the accuracy of the radial velocities. The statistical error on the radial velocities is sigma~0.4 km s^-1 and is mainly due to uncertainties in the zero point of the wavelength calibration. However, we found a systematic bias with respect to the GIRAFFE spectra (~0.9 km s^-1) and to the radial velocities of the standard stars (~0.5 kms^-1) retrieved from the literature. This bias will be corrected in the future data releases, when a common zero point for all the setups and instruments used for the survey will be established., 11 pages, 7 figures, accepted for publication on A&A

Published
2014

4. The Gaia-ESO Survey: Stellar content and elemental abundances in the massive cluster NGC 6705

Author

Cantat-Gaudin, T. Vallenari, A. Zaggia, S. Bragaglia, A. Sordo, R. Drew, J.E. Eisloeffel, J. Farnhill, H.J. Gonzalez-Solares, E. Greimel, R. Irwin, M.J. Kupcu-Yoldas, A. Jordi, C. Blomme, R. Sampedro, L. Costado, M.T. Alfaro, E. Smiljanic, R. Magrini, L. Donati, P. Friel, E.D. Jacobson, H. Abbas, U. Hatzidimitriou, D. Spagna, A. Vecchiato, A. Balaguer-Nunez, L. Lardo, C. Tosi, M. Pancino, E. Klutsch, A. Tautvaisiene, G. Drazdauskas, A. Puzeras, E. Jiménez-Esteban, F. Maiorca, E. Geisler, D. San Roman, I. Villanova, S. Gilmore, G. Randich, S. Bensby, T. Flaccomio, E. Lanzafame, A. Recio-Blanco, A. Damiani, F. Hourihane, A. Jofré, P. De Laverny, P. Masseron, T. Morbidelli, L. Prisinzano, L. Sacco, G.G. Sbordone, L. Worley, C.C.

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Context. Chemically inhomogeneous populations are observed in most globular clusters, but not in open clusters. Cluster mass seems to play a key role in the existence of multiple populations. Aims. Studying the chemical homogeneity of the most massive open clusters is needed to better understand the mechanism of their formation and determine the mass limit under which clusters cannot host multiple populations. Here we studied NGC≠6705, which is a young and massive open cluster located towards the inner region of the Milky Way. This cluster is located inside the solar circle. This makes it an important tracer of the inner disk abundance gradient. Methods. This study makes use of BVI and ri photometry and comparisons with theoretical isochrones to derive the age of NGC≠6705. We study the density profile of the cluster and the mass function to infer the cluster mass. Based on abundances of the chemical elements distributed in the first internal data release of the Gaia-ESO Survey, we study elemental ratios and the chemical homogeneity of the red clump stars. Radial velocities enable us to study the rotation and internal kinematics of the cluster. Results. The estimated ages range from 250 to 316≠Myr, depending on the adopted stellar model. Luminosity profiles and mass functions show strong signs of mass segregation. We derive the mass of the cluster from its luminosity function and from the kinematics, finding values between 3700 M and 11 000 M. After selecting the cluster members from their radial velocities, we obtain a metallicity of [Fe/H] = 0.10 ± 0.06 based on 21 candidate members. Moreover, NGC 6705 shows no sign of the typical correlations or anti-correlations between Al, Mg, Si, and Na, which are expected in multiple populations. This is consistent with our cluster mass estimate, which is lower than the required mass limit proposed in the literature to develop multiple populations. © 2014 ESO .

Published
2014

5. Lithium abundances in CEMP stars

Author

Masseron, T., Johnson, J. A., Lucatello, S., Karakas, A., Plez, B., Beers, T. C., Christlieb, N., Astrophysique Stellaire, Laboratoire Univers et Particules de Montpellier (LUPM), and Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Astrophysics - Solar and Stellar Astrophysics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical imprints of more massive stars (M > 0.8 Msun) that are now extinct. In particular, it is expected that the observed abundance of Li should deviate in these stars from the standard Spite lithium plateau. We study here a sample of 11 metal-poor stars and a double-lined spectroscopic binary with -1.8, Comment: 62 pages, 16 figures, accepted for publication in ApJ

Published
2012

6. Gaia FGK benchmark stars: abundances of alpha and iron-peak elements

Author

Jofré P., Heiter U., Soubiran C., Blanco-Cuaresma S., Masseron T., Nordlander T., Chemin L., Worley C. C., Van Eck S., Hourihane A., Gilmore G., Adibekyan V., Bergemann M., Cantat-Gaudin T., Delgado-Mena E., González Hernández J. I., Guiglion G., Lardo C., de Laverny P., Lind K., Magrini L., Mikolaitis S., Montes D., and Pancino E.

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

In the current era of large spectroscopic surveys of the Milky Way reference stars for calibrating astrophysical parameters and chemical abundances are of paramount importance. We determine elemental abundances of Mg Si Ca Sc Ti V Cr Mn Co and Ni for our predefined set of Gaia FGK benchmark stars. By analysing high resolution and high signal to noise spectra taken from several archive datasets we combined results of eight different methods to determine abundances on a line by line basis. We perform a detailed homogeneous analysis of the systematic uncertainties such as differential versus absolute abundance analysis as well as we assess errors due to NLTE and the stellar parameters in our final abundances. Our results are provided by listing final abundances and the different sources of uncertainties as well as line by line and method by method abundances. The Gaia FGK benchmark stars atmospheric parameters are already being widely used for calibration of several pipelines applied to different surveys. With the added reference abundances of 10 elements this set is very suitable to calibrate the chemical abundances obtained by these pipelines.

Published
2015

7. A VLT-UVES spectrscopic analysis of C-rich Fe-poor stars

Author

Masseron, T., Plez, B., Primas, F., Van Eck, S., and Jorissen, A.

Subjects
Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Large surveys of very metal-poor stars have revealed in recent years that a large fraction of these objects were carbon-rich, analogous to the more metal-rich CH-stars. The abundance peculiarities of CH-stars are commonly explained by mass-transfer from a more evolved companion. In an effort to better understand the origin and importance for Galactic evolution of Fe-poor, C-rich stars, we present abundances determined from high-resolution and high signal-to-noise spectra obtained with the UVES instrument attached to the ESO/VLT. Our analysis of carbon-enhanced objects includes both CH stars and more metal-poor objects, and we explore the link between the two classes. We also present preliminary results of our ongoing radial velocity monitoring., 3 pages, 4 figures, presented at Cool Stars 13, Hamburg, 2004

Published
2006

8. Assessing spectra and thermal inversions due to TiO in hot Jupiter atmospheres

Author

Piette, AAA, Madhusudhan, N, McKemmish, LK, Gandhi, S, Masseron, T, and Welbanks, L

Subjects
planets and satellites: atmospheres, 13. Climate action, planets and satellites: composition, Astrophysics::Solar and Stellar Astrophysics, opacity, Astrophysics::Earth and Planetary Astrophysics, techniques: spectroscopic, methods: numerical
Abstract

Recent detections of thermal inversions in the dayside atmospheres of some hot Jupiters are motivating new avenues to understand the interplay between their temperature structures and other atmospheric conditions. In particular, TiO has long been proposed to cause thermal inversions in hot Jupiters, depending on other factors such as stellar irradiation, C/O, and vertical mixing. TiO also has spectral features in the optical and near-infrared that have been detected. However, interpretations of TiO signatures rely on the accuracy of TiO opacity used in the models. The recently reported Toto TiO line list provides a new opportunity to investigate these dependencies, which is the goal of the present work. First, we investigate how the Toto line list affects observable transmission and emission spectra of hot Jupiters at low and high resolution. The improvement in the Toto line list compared to a previous line list results in observable differences in the model spectra, particularly in the optical at high resolution. Secondly, we explore the interplay between temperature structure, irradiation and composition with TiO as the primary source of optical opacity, using 1D self-consistent atmospheric models. Among other trends, we find that the propensity for thermal inversions due to TiO peaks at C/O$\sim$0.9, consistent with recent studies. Using these models, we further assess metrics to quantify thermal inversions due to TiO, compared to frequently-used Spitzer photometry, over a range in C/O, irradiation, metallicity, gravity and stellar type.

9. How much can we trust high-resolution spectroscopic stellar chemical abundances?

Author

Blanco-Cuaresma, S., Thomas Nordlander, Heiter, U., Jofré, P., Masseron, T., Casamiquela, L., Tabernero, H. M., Bhat, S. S., Casey, A. R., Meléndez, J., and Ramírez, I.

Subjects
Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

To study stellar populations, it is common to combine chemical abundances from different spectroscopic surveys/studies where different setups were used. These inhomogeneities can lead us to inaccurate scientific conclusions. In this work, we studied one aspect of the problem: When deriving chemical abundances from high-resolution stellar spectra, what differences originate from the use of different radiative transfer codes?, Comment: To appear in the Highlights on Spanish Astrophysics IX, Proceedings of the XII Scientific Meeting of the Spanish Astronomical Society

10. The Gaia-ESO Survey: impact of extra mixing on C and N abundances of giant stars

Author

Lagarde, N, Reyle, C, Robin, AC, Tautvaisiene, G, Drazdauskas, A, Mikolaitis, S, Minkeviciute, R, Stonkute, E, Chorniy, Y, Bagdonas, V, Miglio, A, Nasello, G, Gilmore, G, Randich, S, Bensby, T, Bragaglia, A, Flaccomio, E, Francois, P, Korn, AJ, Pancino, E, Smiljanic, R, Bayo, A, Carraro, G, Costado, MT, Jimenez-Esteban, F, Jofre, P, Martell, SL, Masseron, T, Monaco, L, Morbidelli, L, Sbordone, L, Sousa, SG, and Zaggia, S

Subjects
Galaxy: stellar content, stars: abundances, 13. Climate action, Astrophysics::Solar and Stellar Astrophysics, Galaxy: abundances, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 14. Life underwater, stars: evolution, Astrophysics::Galaxy Astrophysics
Abstract

Context. TheGaia-ESO Public Spectroscopic Survey using FLAMES at the VLT has obtained high-resolution UVES spectra for a large number of giant stars, allowing a determination of the abundances of the key chemical elements carbon and nitrogen at their surface. The surface abundances of these chemical species are known to change in stars during their evolution on the red giant branch (RGB) after the first dredge-up episode, as a result of the extra mixing phenomena.Aims. We investigate the effects of thermohaline mixing on C and N abundances using the first comparison between theGaia-ESO survey [C/N] determinations with simulations of the observed fields using a model of stellar population synthesis.Methods. We explore the effects of thermohaline mixing on the chemical properties of giants through stellar evolutionary models computed with the stellar evolution code STAREVOL. We include these stellar evolution models in the Besançon Galaxy model to simulate the [C/N] distributions determined from the UVES spectra of theGaia-ESO survey and to compare them with the observations.Results. Theoretical predictions including the effect of thermohaline mixing are in good agreement with the observations. However, the field stars in theGaia-ESO survey with C and N abundance measurements have a metallicity close to solar, where the efficiency of thermohaline mixing is not very large. The C and N abundances derived by theGaia-ESO survey in open and globular clusters clearly show the impact of thermohaline mixing at low metallicity, which explains the [C/N] value observed in lower mass and older giant stars. Using independent observations of carbon isotopic ratio in clump field stars and open clusters, we also confirm that thermohaline mixing should be taken into account to explain the behaviour of12C/13C as a function of stellar age.Conclusions. Overall, the current model including thermohaline mixing is able to reproduce very well the C and N abundances over the whole metallicity range investigated by theGaia-ESO survey data.

11. The Gaia-ESO survey: Calibrating a relationship between age and the [C/N] abundance ratio with open clusters

Author

Casali, G, Magrini, L, Tognelli, E, Jackson, R, Jeffries, RD, Lagarde, N, Tautvaisiene, G, Masseron, T, Degl'Innocenti, S, Moroni, PG Prada, Kordopatis, G, Pancino, E, Randich, S, Feltzing, S, Sahlholdt, C, Spina, L, Friel, E, Roccatagliata, V, Sanna, N, Bragaglia, A, Drazdauskas, A, Mikolaitis, S, Minkeviciute, R, Stonkute, E, Chorniy, Y, Bagdonas, V, Jimenez-Esteban, F, Martell, S, Van Der Swaelmen, M, Gilmore, G, Vallenari, A, Bensby, T, Koposov, SE, Korn, A, Worley, C, Smiljanic, R, Bergemann, M, Carraro, G, Damiani, F, Prisinzano, L, Bonito, R, Franciosini, E, Gonneau, A, Hourihane, A, Jofre, P, Lewis, J, Morbidelli, L, Sacco, G, Sousa, SG, Zaggia, S, Lanzafame, AC, Heiter, U, Frasca, A, and Bayo, A

Subjects
13. Climate action, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Galaxy: abundances, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, open clusters and associations: general, Astrophysics::Galaxy Astrophysics, Galaxy: disk
Abstract

Context. In the era of large high-resolution spectroscopic surveys such as Gaia-ESO and APOGEE, high-quality spectra can contribute to our understanding of the Galactic chemical evolution by providing abundances of elements that belong to the different nucleosynthesis channels, and also by providing constraints to one of the most elusive astrophysical quantities: stellar age. Aims. Some abundance ratios, such as [C/N], have been proven to be excellent indicators of stellar ages. We aim at providing an empirical relationship between stellar ages and [C/N] using open star clusters, observed by the Gaia-ESO and APOGEE surveys, as calibrators. Methods. We used stellar parameters and abundances from the Gaia-ESO Survey and APOGEE Survey of the Galactic field and open cluster stars. Ages of star clusters were retrieved from the literature sources and validated using a common set of isochrones. We used the same isochrones to determine for each age and metallicity the surface gravity at which the first dredge-up and red giant branch bump occur. We studied the effect of extra-mixing processes in our sample of giant stars, and we derived the mean [C/N] in evolved stars, including only stars without evidence of extra mixing. By combining the Gaia-ESO and APOGEE samples of open clusters, we derived a linear relationship between [C/N] and (logarithmic) cluster ages. Results. We apply our relationship to selected giant field stars in the Gaia-ESO and APOGEE surveys. We find an age separation between thin- and thick-disc stars and age trends within their populations, with an increasing age towards lower metallicity populations. Conclusions. With this empirical relationship, we are able to provide an age estimate for giant stars in which C and N abundances are measured. For giant stars, the isochrone fitting method is indeed less sensitive than for dwarf stars at the turn-off. Our method can therefore be considered as an additional tool to give an independent estimate of the age of giant stars. The uncertainties in their ages is similar to those obtained using isochrone fitting for dwarf stars., Includes STFC and ERC funding.

12. The AMBRE Project: Constraining the lithium evolution in the Milky Way

Author

Prantzos, N., Masseron, T., De Pascale, M., Worley, C., Recio-Blanco, A., De Laverny, P., Guiglion, G., Mikolaitis, Š., Mikolaitis, S., ITA, GBR, and FRA

Subjects
010504 meteorology & atmospheric sciences, Milky Way, Metallicity, chemistry.chemical_element, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Abundance (ecology), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Physics::Atomic Physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, chemistry, Space and Planetary Science, Homogeneous, Astrophysics of Galaxies (astro-ph.GA), Lithium, Astrophysics::Earth and Planetary Astrophysics
Abstract

The chemical evolution of lithium in the Milky Way represents a major problem in modern astrophysics. Indeed, lithium is, on the one hand, easily destroyed in stellar interiors, and, on the other hand, produced at some specific stellar evolutionary stages that are still not well constrained. The goal of this paper is to investigate the lithium stellar content of Milky Way stars in order to put constraints on the lithium chemical enrichment in our Galaxy, in particular in both the thin and thick discs. Thanks to high-resolution spectra from the ESO archive and high quality atmospheric parameters, we were able to build a massive and homogeneous catalogue of lithium abundances for 7300 stars derived with an automatic method coupling, a synthetic spectra grid, and a Gauss-Newton algorithm. We validated these lithium abundances with literature values, including those of the Gaia benchmark stars. In terms of lithium galactic evolution, we show that the interstellar lithium abundance increases with metallicity by 1 dex from [M/H]=-1 dex to +0.0 dex. Moreover, we find that this lithium ISM abundance decreases by about 0.5 dex at super-solar metalllicity. Based on a chemical separation, we also observed that the stellar lithium content in the thick disc increases rather slightly with metallicity, while the thin disc shows a steeper increase. The lithium abundance distribution of alpha-rich, metal-rich stars has a peak at A(Li)~3 dex. We conclude that the thick disc stars suffered of a low lithium chemical enrichment, showing lithium abundances rather close to the Spite plateau while the thin disc stars clearly show an increasing lithium chemical enrichment with the metallicity, probably thanks to the contribution of low-mass stars., Comment: 15 pages, 12 figures, 2 tables

13. The Gaia -ESO Survey: The origin and evolution of s -process elements

Author

Magrini, L, Spina, L, Randich, S, Friel, E, Kordopatis, G, Worley, C, Pancino, E, Bragaglia, A, Donati, P, Tautvaišienė, G, Bagdonas, V, Delgado-Mena, E, Adibekyan, V, Sousa, SG, Jiménez-Esteban, FM, Sanna, N, Roccatagliata, V, Bonito, R, Sbordone, L, Duffau, S, Gilmore, G, Feltzing, S, Jeffries, RD, Vallenari, A, Alfaro, EJ, Bensby, T, Francois, P, Koposov, S, Korn, AJ, Recio-Blanco, A, Smiljanic, R, Bayo, A, Carraro, G, Casey, AR, Costado, MT, Damiani, F, Franciosini, E, Frasca, A, Hourihane, A, Jofré, P, De Laverny, P, Lewis, J, Masseron, T, Monaco, L, Morbidelli, L, Prisinzano, L, Sacco, G, and Zaggia, S

Subjects
13. Climate action, Astrophysics::Solar and Stellar Astrophysics, Galaxy: abundances, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, open clusters and associations: general, Astrophysics::Galaxy Astrophysics, Galaxy: disk
Abstract

Several works have found an increase of the abundances of the s-process neutron-capture elements in the youngest Galactic stellar populations, giving important constraints to stellar and Galactic evolution. We aim to trace the abundance patterns and the time-evolution of five s-process elements in the first peak, Y and Zr, and in the second peak, Ba, La and Ce using the Gaia-ESO idr5 results. From the UVES spectra of cluster member stars, we determined the average composition of clusters with ages >0.1 Gyr. We derived statistical ages and distances of field stars, and we separated them in thin and thick disc populations. We studied the time evolution and dependence on metallicity of abundance ratios using open clusters and field stars. Using our large and homogeneous sample of open clusters, thin and thick disc stars, spanning an age range larger than 10 Gyr, we confirm an increase towards young ages of s-process abundances in the Solar neighbourhood. These trends are well defined for open clusters and stars located nearby the solar position and they may be explained by a late enrichment due to significant contribution to the production of these elements from long-living low-mass stars. At the same time, we found a strong dependence of the s-process abundance ratios with the Galactocentric distance and with the metallicity of the clusters and field stars. Our results, derived from the largest and homogeneous sample of s-process abundances in the literature, confirm the growth with decreasing stellar ages of the s-process abundances in both field and open cluster stars. At the same time, taking advantage of the abundances of open clusters located in a wide Galactocentric range, they open a new view on the dependence of the s-process evolution on the metallicity and star formation history, pointing to different behaviours at various Galactocentric distances.

14. Gaia FGK benchmark stars: new candidates at low metallicities

Author

Hawkins, K, Jofre, P, Heiter, U, Soubiran, C, Blanco-Cuaresma, S, Casagrande, L, Gilmore, G, Lind, K, Magrini, L, Masseron, T, Pancino, E, Randich, S, and Worley, CC

Subjects
13. Climate action, Astrophysics::Instrumentation and Methods for Astrophysics, standards, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, stars: fundamental parameters, Astrophysics::Galaxy Astrophysics, techniques: spectroscopic
Abstract

We have entered an era of large spectroscopic surveys in which we can measure, through automated pipelines, the atmospheric parameters and chemical abundances for large numbers of stars. Calibrating these survey pipelines using a set of "benchmark stars" in order to evaluate the accuracy and precision of the provided parameters and abundances is of utmost importance. The recent proposed set of Gaia FGK benchmark stars of Heiter et al. (2015) has no recommended stars within the critical metallicity range of $-2.0

15. Gaia -ESO Survey: Analysis of pre-main sequence stellar spectra

Author

Antonio Frasca, G. G. Sacco, Ignacio Negueruela, Hugo M. Tabernero, Andreas Korn, Martin Asplund, C. Babusiaux, Loredana Prisinzano, Francesco Damiani, Nigel Hambly, M. T. Costado, G. Carraro, Gerry Gilmore, Giuseppina Micela, Emilio J. Alfaro, Piercarlo Bonifacio, Annette M. N. Ferguson, A. Hourihane, Maria Bergemann, N. A. Walton, E. Brugaletta, Manuel Meyer, John D. Lewis, H. W. Rix, Michael G. Irwin, Vardan Adibekyan, R. Blomme, P. Francois, R. D. Jeffries, A. C. Lanzafame, Sergey E. Koposov, Lorenzo Spina, James Binney, Thomas Masseron, L. Morbidelli, D. Montes, K. Biazzo, S. G. Sousa, Antonella Vallenari, Rodolfo Smiljanic, J. M. Alcalá, Thomas Bensby, C. Allende Prieto, Sergio Messina, Luca Sbordone, Amelia Bayo, A. Bragaglia, Simone Zaggia, C. C. Worley, Janet E. Drew, Ettore Flaccomio, S. Van Eck, Paula Jofre, Laura Magrini, Bengt Edvardsson, Gianni Marconi, J. I. González Hernández, Michiel Cottaar, Rosaria Bonito, Lorenzo Monaco, Ulrike Heiter, J. F. Gameiro, Carmela Lardo, Sofia Feltzing, E. Franciosini, T. Prusti, R. J. Jackson, Vanessa Hill, Sofia Randich, Karin Lind, Ch. Martayan, E. Delgado Mena, A. Klutsch, INAF - Osservatorio Astrofisico di Catania (OACT), Istituto Nazionale di Astrofisica (INAF), University of Turin, INAF - Osservatorio Astrofisico di Arcetri (OAA), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto, Istituto di Astrofisica Spaziale e Fisica cosmica - Palermo (IASF-Pa), Keele University [Keele], Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Lund Observatory, Lund University [Lund], INAF - Osservatorio Astronomico di Palermo (OAPa), Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Señal [Alicante] (DFESTS), Universidad de Alicante, Agence Spatiale Européenne (ESA), European Space Agency (ESA), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Royal Observatory of Belgium [Brussels] (ROB), INAF - Osservatorio Astronomico di Bologna (OABO), Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles (ULB), Uppsala University, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare (INFN), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lanzafame A.C., Frasca A., Damiani F., Franciosini E., Cottaar M., Sousa S.G., Tabernero H.M., Klutsch A., Spina L., Biazzo K., Prisinzano L., Sacco G.G., Randich S., Brugaletta E., Delgado Mena E., Adibekyan V., Montes D., Bonito R., Gameiro J.F., Alcala J.M., Gonzalez Hernandez J.I., Jeffries R., Messina S., Meyer M., Gilmore G., Asplund M., Binney J., Bonifacio P., Drew J.E., Feltzing S., Ferguson A.M.N., Micela G., Negueruela I., Prusti T., Rix H.-W., Vallenari A., Alfaro E.J., Allende Prieto C., Babusiaux C., Bensby T., Blomme R., Bragaglia A., Flaccomio E., Francois P., Hambly N., Irwin M., Koposov S.E., Korn A.J., Smiljanic R., Van Eck S., Walton N., Bayo A., Bergemann M., Carraro G., Costado M.T., Edvardsson B., Heiter U., Hill V., Hourihane A., Jackson R.J., Jofre P., Lardo C., Lewis J., Lind K., Magrini L., Marconi G., Martayan C., Masseron T., Monaco L., Morbidelli L., Sbordone L., Worley C.C., Zaggia S., Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Astrofísica Estelar (AE), Lanzafame, A., Frasca, A., Damiani, F., Franciosini, E., Cottaar, M., Sousa, S., Tabernero, H., Klutsch, A., Spina, L., Biazzo, K., Prisinzano, L., Sacco, G., Randich, S., Brugaletta, E., Delgado Mena, E., Adibekyan, V., Montes, D., Bonito, R., Gameiro, J., Alcalá, J., González Hernández, J., Jeffries, R., Messina, S., Meyer, M., Gilmore, G., Asplund, M., Binney, J., Bonifacio, P., Drew, J., Feltzing, S., Ferguson, A., Micela, G., Negueruela, I., Prusti, T., Rix, H., Vallenari, A., Alfaro, E., Allende Prieto, C., Babusiaux, C., Bensby, T., Blomme, R., Bragaglia, A., Flaccomio, E., Francois, P., Hambly, N., Irwin, M., Koposov, S., Korn, A., Smiljanic, R., Van Eck, S., Walton, N., Bayo, A., Bergemann, M., Carraro, G., Costado, M., Edvardsson, B., Heiter, U., Hill, V., Hourihane, A., Jackson, R., Jofré, P., Lardo, C., Lewis, J., Lind, K., Magrini, L., Marconi, G., Martayan, C., Masseron, T., Monaco, L., Morbidelli, L., Sbordone, L., Worley, C., and Zaggia, S.

Subjects
Accuracy and precision, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: pre-main sequence, Surveys, fundamental parameters [Stars], Astronomical spectroscopy, surveys, Angular diameter, pre-main sequence [Stars], Astrophysics::Solar and Stellar Astrophysics, Survey, data analysis [Methods], education, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Astronomía y Astrofísica, Physics, education.field_of_study, general [Open clusters and associations], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Stars: fundamental parameter, Astronomy and Astrophysic, Effective temperature, open clusters and associations: general, Surface gravity, methods: data analysis, Accretion (astrophysics), Stars, Astrophysics - Solar and Stellar Astrophysics, Methods: data analysis, Open clusters and associations: general, Stars: fundamental parameters, Stars: pre-main sequence, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics::Earth and Planetary Astrophysics, stars: fundamental parameters, Methods: data analysi
Abstract

This paper describes the analysis of UVES and GIRAFFE spectra acquired by the Gaia-ESO Public Spectroscopic Survey in the fields of young clusters whose population includes pre-main sequence (PMS) stars. Both methods that have been extensively used in the past and new ones developed in the contest of the Gaia-ESO survey enterprise are available and used. The internal precision of these quantities is estimated by inter-comparing the results obtained by such different methods, while the accuracy is estimated by comparison with independent external data, like effective temperature and surface gravity derived from angular diameter measurements, on a sample of benchmarks stars. Specific strategies are implemented to deal with fast rotation, accretion signatures, chromospheric activity, and veiling. The analysis carried out on spectra acquired in young clusters' fields during the first 18 months of observations, up to June 2013, is presented in preparation of the first release of advanced data products. Stellar parameters obtained with the higher resolution and larger wavelength coverage from UVES are reproduced with comparable accuracy and precision using the smaller wavelength range and lower resolution of the GIRAFFE setup adopted for young stars, which allows us to provide with confidence stellar parameters for the much larger GIRAFFE sample. Precisions are estimated to be $\approx$ 120 K r.m.s. in Teff, $\approx$0.3 dex r.m.s. in logg, and $\approx$0.15 dex r.m.s. in [Fe/H], for both the UVES and GIRAFFE setups., 22 pages, 18 figures, accepted for publication on A&A

Published
2015
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16. The Gaia-ESO Survey: Chromospheric emission, accretion properties, and rotation in gamma Velorum and Chamaeleon

Author

A. Hourihane, Geert Barentsen, E. Brugaletta, Beate Stelzer, Gerry Gilmore, Paula Jofre, E. Franciosini, Thomas Masseron, G. Pace, K. Biazzo, L. Morbidelli, Luca Pasquini, Emilio J. Alfaro, A. C. Lanzafame, Lorenzo Spina, R. Bonito, Carmela Lardo, Sofia Randich, A. Bragaglia, M. T. Costado, A. Klutsch, C. C. Worley, Enrico Maiorca, S. G. Sousa, Antonio Frasca, J. F. Gameiro, G. G. Sacco, Loredana Prisinzano, Giuseppina Micela, J. M. Alcalá, V. Hill, D. Montes, Javier Lopez-Santiago, Amelia Bayo, R. D. Jeffries, Ettore Flaccomio, ITA, Frasca A., Biazzo K., Lanzafame A.C., Alcala J.M., Brugaletta E., Klutsch A., Stelzer B., Sacco G.G., Spina L., Jeffries R.D., Montes D., Alfaro E.J., Barentsen G., Bonito R., Gameiro J.F., Lopez-Santiago J., Pace G., Pasquini L., Prisinzano L., Sousa S.G., Gilmore G., Randich S., Micela G., Bragaglia A., Flaccomio E., Bayo A., Costado M.T., Franciosini E., Hill V., Hourihane A., Jofre P., Lardo C., Maiorca E., Masseron T., Morbidelli L., Worley C.C., Frasca, A., Biazzo, K., Lanzafame, A., Alcalá, J., Brugaletta, E., Klutsch, A., Stelzer, B., Sacco, G., Spina, L., Jeffries, R., Montes, D., Alfaro, E., Barentsen, G., Bonito, R., Gameiro, J., López-Santiago, J., Pace, G., Pasquini, L., Prisinzano, L., Sousa, S., Gilmore, G., Randich, S., Micela, G., Bragaglia, A., Flaccomio, E., Bayo, A., Costado, M., Franciosini, E., Hill, V., Hourihane, A., Jofré, P., Lardo, C., Maiorca, E., Masseron, T., Morbidelli, L., and Worley, C.

Subjects
Astrofísica, stars: chromospheres, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Rotation, Stars: chromosphere, Open clusters and associations: individual:γVelorum, stars: low-mass, Stars: low-ma, Astrophysics::Solar and Stellar Astrophysics, Open clusters and associations: individual: Chamaeleon I, open clusters and associations: individual: γ Velorum, QC, Astrophysics::Galaxy Astrophysics, QB, Line (formation), Physics, Accretion (meteorology), Diagram, Stars: rotation, Spectral density, Astronomy and Astrophysics, Astronomy and Astrophysic, Stars, Distribution (mathematics), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Chamaeleon, Stars: pre-main sequence, Astrophysics::Earth and Planetary Astrophysics, Stars: chromospheres, Stars: low-mass
Abstract

Aims: One of the goals of the Gaia-ESO Survey (GES), which is conducted with FLAMES at the VLT, is the census and the characterization of the low-mass members of very young clusters and associations. We conduct a comparative study of the main properties of the sources belonging to γ Velorum (γ Vel) and Chamaeleon I (Cha I) young associations, focusing on their rotation, chromospheric radiative losses, and accretion. Methods: We used the fundamental parameters (effective temperature, surface gravity, lithium abundance, and radial velocity) delivered by the GES consortium in the first internal data release to select the members of γ Vel and Cha I among the UVES and GIRAFFE spectroscopic observations. A total of 140 γ Vel members and 74 Cha I members were studied. The procedure adopted by the GES to derive stellar fundamental parameters also provided measures of the projected rotational velocity (vsini). We calculated stellar luminosities through spectral energy distributions, while stellar masses were derived by comparison with evolutionary tracks. The spectral subtraction of low-activity and slowly rotating templates, which are rotationally broadened to match the vsini of the targets, enabled us to measure the equivalent widths (EWs) and the fluxes in the Hα and Hβ lines. The Hα line was also used for identifying accreting objects, on the basis of its EW and the width at the 10% of the line peak (10%W), and for evaluating the mass accretion rate (Ṁacc). Results: The distribution of vsini for the members of γ Vel displays a peak at about 10 km s-1 with a tail toward faster rotators. There is also some indication of a different vsini distribution for the members of its two kinematical populations. Most of these stars have Hα fluxes corresponding to a saturated activity regime. We find a similar distribution, but with a narrower peak, for Cha I. Only a handful of stars in γ Vel display signatures of accretion, while many more accretors were detected in the younger Cha I, where the highest Hα fluxes are mostly due to accretion, rather than to chromospheric activity. Accreting and active stars occupy two different regions in a Teff-flux diagram and we propose a criterion for distinguishing them. We derive Ṁacc in the ranges 10-11-10-9 M☉ yr-1 and 10-10-10-7 M☉ yr-1 for γ Vel and Cha I accretors, respectively. We find less scatter in the Ṁacc - M⋆ relation derived through the Hα EWs, when compared to the Hα10%W diagnostics, in agreement with other authors. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 188.B-3002.Tables 5, 6, and Appendix A are available in electronic form at http://www.aanda.orgTables 2-4 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/575/A4

Published
2015

17. The 16th Data Release of the Sloan Digital Sky Surveys : First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra

Author

Romina Ahumada, Carlos Allende Prieto, Andrés Almeida, Friedrich Anders, Scott F. Anderson, Brett H. Andrews, Borja Anguiano, Riccardo Arcodia, Eric Armengaud, Marie Aubert, Santiago Avila, Vladimir Avila-Reese, Carles Badenes, Christophe Balland, Kat Barger, Jorge K. Barrera-Ballesteros, Sarbani Basu, Julian Bautista, Rachael L. Beaton, Timothy C. Beers, B. Izamar T. Benavides, Chad F. Bender, Mariangela Bernardi, Matthew Bershady, Florian Beutler, Christian Moni Bidin, Jonathan Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Médéric Boquien, Jura Borissova, Jo Bovy, W. N. Brandt, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Martin Bureau, Adam Burgasser, Etienne Burtin, Mariana Cano-Díaz, Raffaella Capasso, Michele Cappellari, Ricardo Carrera, Solène Chabanier, William Chaplin, Michael Chapman, Brian Cherinka, Cristina Chiappini, Peter Doohyun Choi, S. Drew Chojnowski, Haeun Chung, Nicolas Clerc, Damien Coffey, Julia M. Comerford, Johan Comparat, Luiz da Costa, Marie-Claude Cousinou, Kevin Covey, Jeffrey D. Crane, Katia Cunha, Gabriele da Silva Ilha, Yu Sophia Dai, Sanna B. Damsted, Jeremy Darling, James W. Davidson, Roger Davies, Kyle Dawson, Nikhil De, Axel de la Macorra, Nathan De Lee, Anna Bárbara de Andrade Queiroz, Alice Deconto Machado, Sylvain de la Torre, Flavia Dell’Agli, Hélion du Mas des Bourboux, Aleksandar M. Diamond-Stanic, Sean Dillon, John Donor, Niv Drory, Chris Duckworth, Tom Dwelly, Garrett Ebelke, Sarah Eftekharzadeh, Arthur Davis Eigenbrot, Yvonne P. Elsworth, Mike Eracleous, Ghazaleh Erfanianfar, Stephanie Escoffier, Xiaohui Fan, Emily Farr, José G. Fernández-Trincado, Diane Feuillet, Alexis Finoguenov, Patricia Fofie, Amelia Fraser-McKelvie, Peter M. Frinchaboy, Sebastien Fromenteau, Hai Fu, Lluís Galbany, Rafael A. Garcia, D. A. García-Hernández, Luis Alberto Garma Oehmichen, Junqiang Ge, Marcio Antonio Geimba Maia, Doug Geisler, Joseph Gelfand, Julian Goddy, Violeta Gonzalez-Perez, Kathleen Grabowski, Paul Green, Catherine J. Grier, Hong Guo, Julien Guy, Paul Harding, Sten Hasselquist, Adam James Hawken, Christian R. Hayes, Fred Hearty, S. Hekker, David W. Hogg, Jon A. Holtzman, Danny Horta, Jiamin Hou, Bau-Ching Hsieh, Daniel Huber, Jason A. S. Hunt, J. Ider Chitham, Julie Imig, Mariana Jaber, Camilo Eduardo Jimenez Angel, Jennifer A. Johnson, Amy M. Jones, Henrik Jönsson, Eric Jullo, Yerim Kim, Karen Kinemuchi, Charles C. Kirkpatrick IV, George W. Kite, Mark Klaene, Jean-Paul Kneib, Juna A. Kollmeier, Hui Kong, Marina Kounkel, Dhanesh Krishnarao, Ivan Lacerna, Ting-Wen Lan, Richard R. Lane, David R. Law, Jean-Marc Le Goff, Henry W. Leung, Hannah Lewis, Cheng Li, Jianhui Lian, Lihwai Lin, Dan Long, Penélope Longa-Peña, Britt Lundgren, Brad W. Lyke, J. Ted Mackereth, Chelsea L. MacLeod, Steven R. Majewski, Arturo Manchado, Claudia Maraston, Paul Martini, Thomas Masseron, Karen L. Masters, Savita Mathur, Richard M. McDermid, Andrea Merloni, Michael Merrifield, Szabolcs Mészáros, Andrea Miglio, Dante Minniti, Rebecca Minsley, Takamitsu Miyaji, Faizan Gohar Mohammad, Benoit Mosser, Eva-Maria Mueller, Demitri Muna, Andrea Muñoz-Gutiérrez, Adam D. Myers, Seshadri Nadathur, Preethi Nair, Kirpal Nandra, Janaina Correa do Nascimento, Rebecca Jean Nevin, Jeffrey A. Newman, David L. Nidever, Christian Nitschelm, Pasquier Noterdaeme, Julia E. O’Connell, Matthew D. Olmstead, Daniel Oravetz, Audrey Oravetz, Yeisson Osorio, Zachary J. Pace, Nelson Padilla, Nathalie Palanque-Delabrouille, Pedro A. Palicio, Hsi-An Pan, Kaike Pan, James Parker, Romain Paviot, Sebastien Peirani, Karla Peña Ramŕez, Samantha Penny, Will J. Percival, Ismael Perez-Fournon, Ignasi Pérez-Ràfols, Patrick Petitjean, Matthew M. Pieri, Marc Pinsonneault, Vijith Jacob Poovelil, Joshua Tyler Povick, Abhishek Prakash, Adrian M. Price-Whelan, M. Jordan Raddick, Anand Raichoor, Amy Ray, Sandro Barboza Rembold, Mehdi Rezaie, Rogemar A. Riffel, Rogério Riffel, Hans-Walter Rix, Annie C. Robin, A. Roman-Lopes, Carlos Román-Zúñiga, Benjamin Rose, Ashley J. Ross, Graziano Rossi, Kate Rowlands, Kate H. R. Rubin, Mara Salvato, Ariel G. Sánchez, Laura Sánchez-Menguiano, José R. Sánchez-Gallego, Conor Sayres, Adam Schaefer, Ricardo P. Schiavon, Jaderson S. Schimoia, Edward Schlafly, David Schlegel, Donald P. Schneider, Mathias Schultheis, Axel Schwope, Hee-Jong Seo, Aldo Serenelli, Arman Shafieloo, Shoaib Jamal Shamsi, Zhengyi Shao, Shiyin Shen, Matthew Shetrone, Raphael Shirley, Víctor Silva Aguirre, Joshua D. Simon, M. F. Skrutskie, Anže Slosar, Rebecca Smethurst, Jennifer Sobeck, Bernardo Cervantes Sodi, Diogo Souto, David V. Stark, Keivan G. Stassun, Matthias Steinmetz, Dennis Stello, Julianna Stermer, Thaisa Storchi-Bergmann, Alina Streblyanska, Guy S. Stringfellow, Amelia Stutz, Genaro Suárez, Jing Sun, Manuchehr Taghizadeh-Popp, Michael S. Talbot, Jamie Tayar, Aniruddha R. Thakar, Riley Theriault, Daniel Thomas, Zak C. Thomas, Jeremy Tinker, Rita Tojeiro, Hector Hernandez Toledo, Christy A. Tremonti, Nicholas W. Troup, Sarah Tuttle, Eduardo Unda-Sanzana, Marica Valentini, Jaime Vargas-González, Mariana Vargas-Magaña, Jose Antonio Vázquez-Mata, M. Vivek, David Wake, Yuting Wang, Benjamin Alan Weaver, Anne-Marie Weijmans, Vivienne Wild, John C. Wilson, Robert F. Wilson, Nathan Wolthuis, W. M. Wood-Vasey, Renbin Yan, Meng Yang, Christophe Yèche, Olga Zamora, Pauline Zarrouk, Gail Zasowski, Kai Zhang, Cheng Zhao, Gongbo Zhao, Zheng Zheng, Guangtun Zhu, Hu Zou, Department of Physics, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofisica de Canarias (IAC), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional Autónoma de México (UNAM), Department of Astrophysical Sciences [Princeton], Princeton University, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Department of Astronomy, Yale University [New Haven], University of Notre Dame [Indiana] (UND), Department of Physics and Astronomy [Philadelphia], University of Pennsylvania [Philadelphia], University of Wisconsin-Madison, Texas Tech University Health Sciences Center, Texas Tech University [Lubbock] (TTU), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), California Institute of Technology (CALTECH), Sub-department of Astrophysics [Oxford], Department of Physics [Oxford], University of Oxford [Oxford]-University of Oxford [Oxford], Center for Astrophysics and Space Sciences [La Jolla] (CASS), University of California [San Diego] (UC San Diego), University of California-University of California, Department of Psychology, St John's University, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Departamento de FisicaTeorica e IFT-UAM/CSIC, Universidad Autonoma de Madrid (UAM), Lowell Observatory [Flagstaff], Observatorio Nacional [Rio de Janeiro], Vernalis (R&D) Ltd, Special Care Dentistry, UCLH Eastman Dental Hospital, University of Utah, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universidad de La Laguna [Tenerife - SP] (ULL), University of Virginia [Charlottesville], University of Wyoming (UW), School of Physics and Astronomy, University of Birmingham [Birmingham], Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Arizona State University [Tempe] (ASU), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Max-Planck-Institut für Astronomie (MPIA), Texas Christian University (TCU), Department of Physics and Astronomy [Irvine], University of California [Irvine] (UCI), Department of Physics and Astronomy [Pittsburgh], University of Pittsburgh (PITT), Pennsylvania Commonwealth System of Higher Education (PCSHE)-Pennsylvania Commonwealth System of Higher Education (PCSHE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), New York University [New York] (NYU), NYU System (NYU), Research Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, New Mexico State University, Pennsylvania State University (Penn State), Penn State System, Princess Margaret Hospital, University of Toronto, Cognition, Langues, Langage, Ergonomie (CLLE-ERSS), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Toulouse - Jean Jaurès (UT2J)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), J. A. Baker Institute, Cornell University [New York], Institute of Infection, Immunity & Inflammation, University of Glasgow, Sainsbury Laboratory Cambridge University (SLCU), University of Cambridge [UK] (CAM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Carnegie Observatories, Carnegie Institution for Science [Washington], Institute of Science and Technology [Austria] (IST Austria), Universidad de Atacama, Department of Chemical and Biomolecular Engineering, Universidad de Antofagasta, Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Institute of cosmology and gravitation, University of Portsmouth, Institut d'Astronomie et d'Astrophysique [Bruxelles] (IAA), Université libre de Bruxelles (ULB), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Max-Planck-Institut für Astrophysik (MPA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Département des Sciences et Gestion de l'Environnement/Océanologie [Liège], Université de Liège, Universidad Andrés Bello [Santiago] (UNAB), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Montana State University (MSU), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Institut Lagrange de Paris, Sorbonne Université (SU), The Wellcome Trust Centre for Human Genetics [Oxford], University of Oxford [Oxford], Liverpool John Moores University (LJMU), Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), Chinese Academy of Sciences [Beijing] (CAS), McDonald Observatory, University of Texas at Austin [Austin], Astronomy Centre, University of Sussex, Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], University of Washington [Seattle], Vanderbilt University [Nashville], Stellar Astrophysics Centre [Aarhus] (SAC), University of Colorado [Boulder], Laboratoire de Biochimie Médicale (LBM), CHU Rouen, Normandie Université (NU)-Normandie Université (NU), University of St Andrews [Scotland], Instituto de Astronomıa, universidad catolica del Norte, Institut d'Astrophysique et de Géophysique [Liège], Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Department of Computer Science and Engineering [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Dunlap Institute for Astronomy and Astrophysics [Toronto], World Bank, State Key Laboratory in Computer Science [Beijing] (SKLCS), Institute of Software Chinese Academy of Sciences [Beijing], Nanjing University of Information Science and Technology (NUIST), Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Johns Hopkins University (JHU), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Pennsylvania, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Oxford-University of Oxford, University of California (UC)-University of California (UC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universidad Autónoma de Madrid (UAM), University of Virginia, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), University of California [Irvine] (UC Irvine), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Carnegie Institution for Science, Institute of Science and Technology [Klosterneuburg, Austria] (IST Austria), Harvard University-Smithsonian Institution, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Oxford, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Ahumada R., Prieto C.A., Almeida A., Anders F., Anderson S.F., Andrews B.H., Anguiano B., Arcodia R., Armengaud E., Aubert M., Avila S., Avila-Reese V., Badenes C., Balland C., Barger K., Barrera-Ballesteros J.K., Basu S., Bautista J., Beaton R.L., Beers T.C., Benavides B.I.T., Bender C.F., Bernardi M., Bershady M., Beutler F., Bidin C.M., Bird J., Bizyaev D., Blanc G.A., Blanton M.R., Boquien M., Borissova J., Bovy J., Brandt W.N., Brinkmann J., Brownstein J.R., Bundy K., Bureau M., Burgasser A., Burtin E., Cano-Diaz M., Capasso R., Cappellari M., Carrera R., Chabanier S., Chaplin W., Chapman M., Cherinka B., Chiappini C., Doohyun Choi P., Chojnowski S.D., Chung H., Clerc N., Coffey D., Comerford J.M., Comparat J., Da Costa L., Cousinou M.-C., Covey K., Crane J.D., Cunha K., Ilha G.D.S., Dai Y.S., Damsted S.B., Darling J., Davidson J.W., Davies R., Dawson K., De N., De La Macorra A., De Lee N., Queiroz A.B.D.A., Deconto Machado A., De La Torre S., Dell'Agli F., Du Mas Des Bourboux H., Diamond-Stanic A.M., Dillon S., Donor J., Drory N., Duckworth C., Dwelly T., Ebelke G., Eftekharzadeh S., Davis Eigenbrot A., Elsworth Y.P., Eracleous M., Erfanianfar G., Escoffier S., Fan X., Farr E., Fernandez-Trincado J.G., Feuillet D., Finoguenov A., Fofie P., Fraser-Mckelvie A., Frinchaboy P.M., Fromenteau S., Fu H., Galbany L., Garcia R.A., Garcia-Hernandez D.A., Oehmichen L.A.G., Ge J., Maia M.A.G., Geisler D., Gelfand J., Goddy J., Gonzalez-Perez V., Grabowski K., Green P., Grier C.J., Guo H., Guy J., Harding P., Hasselquist S., Hawken A.J., Hayes C.R., Hearty F., Hekker S., Hogg D.W., Holtzman J.A., Horta D., Hou J., Hsieh B.-C., Huber D., Hunt J.A.S., Chitham J.I., Imig J., Jaber M., Angel C.E.J., Johnson J.A., Jones A.M., Jonsson H., Jullo E., Kim Y., Kinemuchi K., Kirkpatrick Iv C.C., Kite G.W., Klaene M., Kneib J.-P., Kollmeier J.A., Kong H., Kounkel M., Krishnarao D., Lacerna I., Lan T.-W., Lane R.R., Law D.R., Le Goff J.-M., Leung H.W., Lewis H., Li C., Lian J., Lin L., Long D., Longa-Peña P., Lundgren B., Lyke B.W., Ted Mackereth J., Macleod C.L., Majewski S.R., Manchado A., Maraston C., Martini P., Masseron T., Masters K.L., Mathur S., McDermid R.M., Merloni A., Merrifield M., Meszaros S., Miglio A., Minniti D., Minsley R., Miyaji T., Mohammad F.G., Mosser B., Mueller E.-M., Muna D., Muñoz-Gutierrez A., Myers A.D., Nadathur S., Nair P., Nandra K., Do Nascimento J.C., Nevin R.J., Newman J.A., Nidever D.L., Nitschelm C., Noterdaeme P., O'Connell J.E., Olmstead M.D., Oravetz D., Oravetz A., Osorio Y., Pace Z.J., Padilla N., Palanque-Delabrouille N., Palicio P.A., Pan H.-A., Pan K., Parker J., Paviot R., Peirani S., Ramrez K.P., Penny S., Percival W.J., Perez-Fournon I., Perez-Rafols I., Petitjean P., Pieri M.M., Pinsonneault M., Poovelil V.J., Povick J.T., Prakash A., Price-Whelan A.M., Raddick M.J., Raichoor A., Ray A., Rembold S.B., Rezaie M., Riffel R.A., Riffel R., Rix H.-W., Robin A.C., Roman-Lopes A., Roman-Zuñiga C., Rose B., Ross A.J., Rossi G., Rowlands K., Rubin K.H.R., Salvato M., Sanchez A.G., Sanchez-Menguiano L., Sanchez-Gallego J.R., Sayres C., Schaefer A., Schiavon R.P., Schimoia J.S., Schlafly E., Schlegel D., Schneider D.P., Schultheis M., Schwope A., Seo H.-J., Serenelli A., Shafieloo A., Shamsi S.J., Shao Z., Shen S., Shetrone M., Shirley R., Aguirre V.S., Simon J.D., Skrutskie M.F., Slosar A., Smethurst R., Sobeck J., Sodi B.C., Souto D., Stark D.V., Stassun K.G., Steinmetz M., Stello D., Stermer J., Storchi-Bergmann T., Streblyanska A., Stringfellow G.S., Stutz A., Suarez G., Sun J., Taghizadeh-Popp M., Talbot M.S., Tayar J., Thakar A.R., Theriault R., Thomas D., Thomas Z.C., Tinker J., Tojeiro R., Toledo H.H., Tremonti C.A., Troup N.W., Tuttle S., Unda-Sanzana E., Valentini M., Vargas-Gonzalez J., Vargas-Magaña M., Vazquez-Mata J.A., Vivek M., Wake D., Wang Y., Weaver B.A., Weijmans A.-M., Wild V., Wilson J.C., Wilson R.F., Wolthuis N., Wood-Vasey W.M., Yan R., Yang M., Yeche C., Zamora O., Zarrouk P., Zasowski G., Zhang K., Zhao C., Zhao G., Zheng Z., Zhu G., Zou H., Alfred P. Sloan Foundation, and Department of Energy (US)

Subjects
Optical telescopes, SAMPLE, Astrophysics, 01 natural sciences, Astronomi, astrofysik och kosmologi, Infrared astronomy, Observatory, Astronomy, Astrophysics and Cosmology, Astrophysics::Solar and Stellar Astrophysics, REDSHIFT 0.8, redshift surveys, stellar spectral lines, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, media_common, Astronomy databases, Redshift surveys, Physics, Astrophysics::Instrumentation and Methods for Astrophysics, stellar properties, CATALOG, astro-ph.CO, astronomy databases, Data release, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], infrared astonomy, TELESCOPE, astro-ph.GA, media_common.quotation_subject, Astrophysics::Cosmology and Extragalactic Astrophysics, MASS, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Galactic abundances, Stellar properties, 0103 physical sciences, Astrophysics::Galaxy Astrophysics, DISTANCES, Stellar spectral lines, 010308 nuclear & particles physics, Astronomy and Astrophysics, optical telescopes, 115 Astronomy, Space science, Galaxy, GALAXY, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], STELLAR, 13. Climate action, Space and Planetary Science, Sky, [SDU]Sciences of the Universe [physics], galactic abundances, MILKY, astro-ph.IM, SDSS-IV MANGA
Abstract

This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17)., Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS website is www.sdss.org.

Published
2020
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18. The Gaia -ESO Survey: Properties of newly discovered Li-rich giants

Author

C. Régulo, Giovanni Carraro, Luca Sbordone, Amelia Bayo, Rafael A. García, E. Franciosini, Thierry Morel, X. Fu, Arnas Drazdauskas, Thomas Bensby, Alejandra Recio-Blanco, Laura Magrini, B. Mosser, Angela Bragaglia, Savita Mathur, Simone Zaggia, L. Prisinzano, L. Morbidelli, R. de Assis Peralta, Lorenzo Monaco, A. C. Lanzafame, Antonio Frasca, Sofia Randich, M. T. Costado, Paula Jofre, V. Adibekyan, P. de Laverny, Karin Lind, Andreas J. Korn, Rodolfo Smiljanic, Grazina Tautvaisiene, L. Pasquini, Elena Pancino, Thomas Masseron, Marica Valentini, S. G. Sousa, Saskia Hekker, Antonella Vallenari, Josefina Montalbán, Gerard Gilmore, D. Feuillet, Carmela Lardo, Sofia Feltzing, Sarah L. Martell, INAF - Osservatorio Astronomico di Bologna (OABO), Istituto Nazionale di Astrofisica (INAF), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Matériaux divisés, interfaces, réactivité, électrochimie (MADIREL), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Space Science Institute [Boulder] (SSI), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Departamento de Astrofísica [La laguna], Universidad de La Laguna [Tenerife - SP] (ULL), School of Physics and Astronomy, University of Birmingham [Birmingham], Dipartimento di Scienze e Tecnologie Aerospaziali - Politecnico, Politecnico di Milano [Milan] (POLIMI), Lund Observatory, Lund University [Lund], INAF - Osservatorio Astronomico di Padova (OAPD), Department of Astronomy and Space Physics [Uppsala], Uppsala University, INAF - Osservatorio Astrofisico di Catania (OACT), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare (INFN), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Smiljanic R., Franciosini E., Bragaglia A., Tautvaisiene G., Fu X., Pancino E., Adibekyan V., Sousa S.G., Randich S., Montalban J., Pasquini L., Magrini L., Drazdauskas A., Garcia R.A., Mathur S., Mosser B., Regulo C., De Assis Peralta R., Hekker S., Feuillet D., Valentini M., Morel T., Martell S., Gilmore G., Feltzing S., Vallenari A., Bensby T., Korn A.J., Lanzafame A.C., Recio-Blanco A., Bayo A., Carraro G., Costado M.T., Frasca A., Jofre P., Lardo C., De Laverny P., Lind K., Masseron T., Monaco L., Morbidelli L., Prisinzano L., Sbordone L., Zaggia S., ITA, USA, GBR, FRA, DEU, ESP, AUS, BEL, CHL, DNK, LTU, POL, PRT, SWE, CHE, Universidade do Porto = University of Porto, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Gilmore, Gerard [0000-0003-4632-0213], Apollo - University of Cambridge Repository, Osservatorio Astronomico di Bologna (OABO), Universidade do Porto [Porto], Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional de Colombia, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Fisica Nucleare [Milano] (INFN), and PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
barium stars, k-giant, Astrophysics, Stars: late-type, GALACTIC BULGE, mass-loss, 7. Clean energy, 01 natural sciences, LITHIUM ENRICHMENT, Bulge, Planet, Asymptotic giant branch, EVOLVED STARS, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Physics, K-GIANT, [PHYS]Physics [physics], open clusters, red giants, LATE-TYPE STARS, Evolution [Stars], Red-giant branch, evolved stars, Stars: evolution, Astrophysics - Solar and Stellar Astrophysics, late-type [Stars], chemical-composition, Astrophysics::Earth and Planetary Astrophysics, Stars: abundance, stars: abundances, late-type stars, FOS: Physical sciences, Abundances [Stars], Astrophysics::Cosmology and Extragalactic Astrophysics, galactic bulge, CHEMICAL-COMPOSITION, 0103 physical sciences, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Infrared excess, 010308 nuclear & particles physics, Astronomy and Astrophysics, MASS-LOSS, BARIUM STARS, Accretion (astrophysics), lithium enrichment, RED GIANTS, Stars, Stars: abundances, Space and Planetary Science, 13. Climate action, OPEN CLUSTERS, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Open cluster
Abstract

Aims. We report 20 new lithium-rich giants discovered within the Gaia-ESO Survey, including the first Li-rich giant with an evolutionary stage confirmed by CoRoT (Convection, Rotation and planetary Transits) data. We present a detailed overview of the properties of these 20 stars., Methods. Atmospheric parameters and abundances were derived in model atmosphere analyses using medium-resolution GIRAFFE or high-resolution UVES (Ultraviolet and Visual Echelle Spectrograph) spectra. These results are part of the fifth internal data release of the Gaia-ESO Survey. The Li abundances were corrected for non-local thermodynamical equilibrium effects. Other stellar properties were investigated for additional peculiarities (the core of strong lines for signs of magnetic activity, infrared magnitudes, rotational velocities, chemical abundances, and Galactic velocities). We used Gaia DR2 parallaxes to estimate distances and luminosities., Results. The giants have A(Li) > 2.2 dex. The majority of them (14 of 20 stars) are in the CoRoT fields. Four giants are located in the field of three open clusters, but are not members. Two giants were observed in fields towards the Galactic bulge, but likely lie in the inner disc. One of the bulge field giants is super Li-rich with A(Li) = 4.0 dex., Conclusions. We identified one giant with infrared excess at 22 mu m. Two other giants, with large v sin i, might be Li-rich because of planet engulfment. Another giant is found to be barium enhanced and thus could have accreted material from a former asymptotic giant branch companion. Otherwise, in addition to the Li enrichment, the evolutionary stages are the only other connection between these new Li-rich giants. The CoRoT data confirm that one Li-rich giant is at the core-He burning stage. The other giants are concentrated in close proximity to the red giant branch luminosity bump, the core-He burning stages, or the early-asymptotic giant branch. This is very clear from the Gaia-based luminosities of the Li-rich giants. This is also seen when the CoRoT Li-rich giants are compared to a larger sample of 2252 giants observed in the CoRoT fields by the Gaia-ESO Survey, which are distributed throughout the red giant branch in the T-eff-log g diagram. These observations show that the evolutionary stage is a major factor for the Li enrichment in giants. Other processes, such as planet accretion, contribute at a smaller scale.

Published
2018
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19. The Gaia-ESO Survey: revisiting the Li-rich giant problem

Author

L. Morbidelli, Tomaž Zwitter, Thomas Masseron, Grant M. Kennedy, Lorenzo Monaco, S. G. Sousa, Rodolfo Smiljanic, A. Hourihane, Loredana Prisinzano, Giovanni Carraro, Laura Magrini, Angela Bragaglia, E. Franciosini, Alejandra Recio-Blanco, P. de Laverny, Clare Worley, Gražina Tautvaišienė, G. Ruchti, A. C. Lanzafame, P. Donati, G. G. Sacco, M. T. Costado, Sofia Randich, Karin Lind, Thierry Morel, Andreas Korn, Marica Valentini, E. Delgado Mena, Luca Sbordone, Simone Zaggia, Sergey E. Koposov, V. Silva Aguirre, Cristina Chiappini, Antonio Frasca, R. D. Jeffries, Francesco Damiani, P. Francois, Paula Jofre, James R. Lewis, Andrea Miglio, Ettore Flaccomio, Gerard Gilmore, Thomas Bensby, Y. Chorniy, Elena Pancino, Carmela Lardo, Sofia Feltzing, Sarah L. Martell, Josefina Montalbán, Andrew R. Casey, Antonella Vallenari, Casey, Andrew [0000-0003-0174-0564], Gilmore, Gerard [0000-0003-4632-0213], Kennedy, Grant [0000-0001-6831-7547], Koposov, Sergey [0000-0003-2644-135X], Worley, Clare [0000-0001-9310-2898], Apollo - University of Cambridge Repository, Casey A.R., Ruchti G., Masseron T., Randich S., Gilmore G., Lind K., Kennedy G.M., Koposov S.E., Hourihane A., Franciosini E., Lewis J.R., Magrini L., Morbidelli L., Sacco G.G., Worley C.C., Feltzing S., Jeffries R.D., Vallenari A., Bensby T., Bragaglia A., Flaccomio E., Francois P., Korn A.J., Lanzafame A., Pancino E., Recio-Blanco A., Smiljanic R., Carraro G., Costado M.T., Damiani F., Donati P., Frasca A., Jofre P., Lardo C., de Laverny P., Monaco L., Prisinzano L., Sbordone L., Sousa S.G., Tautvaisiene G., Zaggia S., Zwitter T., Mena E.D., Chorniy Y., Martell S.L., Aguirre V.S., Miglio A., Chiappini C., Montalban J., Morel T., and Valentini M.

Subjects
stars: abundancess, astro-ph.SR, stars: abundances, Metallicity, Bright giant, FOS: Physical sciences, CLUSTER NGC 362, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, GALACTIC BULGE, 01 natural sciences, Abundance, Planet, QB460, 0103 physical sciences, Hot Jupiter, EVOLVED STARS, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Stellar evolution, QC, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QB, Physics, 010308 nuclear & particles physics, MASS RED GIANTS, Astronomy, Astronomy and Astrophysics, PLANET FORMATION, Giant star, Stars, Accretion (astrophysics), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, K-GIANTS, LITHIUM ABUNDANCES, STELLAR EVOLUTION, PRE-MAIN-SEQUENCE, SUN-LIKE STARS, Astrophysics::Earth and Planetary Astrophysics, QB799
Abstract

The discovery of lithium-rich giants contradicts expectations from canonical stellar evolution. Here we report on the serendipitous discovery of 20 Li-rich giants observed during the Gaia-ESO Survey, which includes the first nine Li-rich giant stars known towards the CoRoT fields. Most of our Li-rich giants have near-solar metallicities, and stellar parameters consistent with being before the luminosity bump. This is difficult to reconcile with deep mixing models proposed to explain lithium enrichment, because these models can only operate at later evolutionary stages: at or past the luminosity bump. In an effort to shed light on the Li-rich phenomenon, we highlight recent evidence of the tidal destruction of close-in hot Jupiters at the sub-giant phase. We note that when coupled with models of planet accretion, the observed destruction of hot Jupiters actually predicts the existence of Li-rich giant stars, and suggests Li-rich stars should be found early on the giant branch and occur more frequently with increasing metallicity. A comprehensive review of all known Li-rich giant stars reveals that this scenario is consistent with the data. However more evolved or metal-poor stars are less likely to host close-in giant planets, implying that their Li-rich origin requires an alternative explanation, likely related to mixing scenarios rather than external phenomena., This work is based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 188.B-3002. These data products have been processed by the Cambridge Astronomy Survey Unit (CASU) at the Institute of Astronomy, University of Cambridge, and by the FLAMES/UVES reduction team at INAF/Osservatorio Astrofisico di Arcetri. These data have been obtained from the $\textit{Gaia}$-ESO Survey Data Archive, prepared and hosted by the Wide Field Astronomy Unit, Institute for Astronomy, University of Edinburgh, which is funded by the UK Science and Technology Facilities Council. This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541. We acknowledge the support from INAF and the Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR) in the form of the grant Premiale VLT 2012 and the Chemical and Dynamical Evolution of the Milky Way and Local Group Galaxies (prot. 2010LY5N2T). The results presented here benefit from discussions held during the $\textit{Gaia}$-ESO workshops and conferences supported by the ESF (European Science Foundation) through the GREAT Research Network Programme. GR acknowledges support from the project grant ‘The New Milky Way’ from the Knut and Alice Wallenberg Foundation. GMK is supported by the Royal Society as a Royal Society University Research Fellow. LS acknowledges support provided by the Chilean Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC120009, awarded to the Millennium Institute of Astrophysics, MAS. Funding for the Stellar Astrophysics Centre is provided by the Danish National Research Foundation. The research is supported by the ASTERISK project (ASTERoseismic Investigations with SONG and Kepler) funded by the European Research Council (Grant agreement no. 267864). VSA acknowledges support from VILLUM FONDEN (research grant 10118). SLM acknowledges support from the Australian Research Council through DECRA fellowship DE140100598. TM acknowledges financial support from Belspo for contract PRODEX Gaia-DPAC. JM acknowledges the support from the European Research Council Consolidator Grant funding scheme (project STARKEY, G.A. no. 615604). This research has made use of the ExoDat Database, operated at LAM-OAMP, Marseille, France, on behalf of the CoRoT/Exoplanet programme. This research made use of astropy, a community-developed core python package for Astronomy (Astropy Collaboration et al. 2013). This research has made use of NASA's Astrophysics Data System Bibliographic Services., This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/mnras/stw1512

Published
2016
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20. The Gaia-ESO Survey: Empirical determination of the precision of stellar radial velocities and projected rotation velocities

Author

Annette M. N. Ferguson, Francesco Damiani, Gerard Gilmore, Angela Bragaglia, Martin Asplund, Giovanni Carraro, Vanessa Hill, L. Morbidelli, Paula Jofre, Antonio Frasca, Elena Pancino, A. C. Lanzafame, M. T. Costado, Bengt Edvardsson, A. Hourihane, Thomas Bensby, Antonella Vallenari, T. Prusti, Andreas Korn, Nicholas A. Walton, Carmela Lardo, Lorenzo Monaco, Sofia Feltzing, Ulrike Heiter, P. de Laverny, L. Prisinzano, Emilio J. Alfaro, C. Babusiaux, E. Franciosini, Clare Worley, Hans-Walter Rix, C. Allende Prieto, S. G. Sousa, Laura Magrini, Rodolfo Smiljanic, Christophe Martayan, G. G. Sacco, Maria Bergemann, P. Francois, R. J. Jackson, R. Blomme, Alejandra Recio-Blanco, Nigel Hambly, Sofia Randich, Karin Lind, Piercarlo Bonifacio, Gianni Marconi, R. D. Jeffries, Luca Sbordone, James R. Lewis, S. Van Eck, Amelia Bayo, James Binney, I. Neguerela, Simone Zaggia, Ettore Flaccomio, Janet E. Drew, Mike Irwin, Giuseppina Micela, Sergey E. Koposov, Thomas Masseron, Jackson R.J., Jeffries R.D., Lewis J., Koposov S.E., Sacco G.G., Randich S., Gilmore G., Asplund M., Binney J., Bonifacio P., Drew J.E., Feltzing S., Ferguson A.M.N., Micela G., Neguerela I., Prusti T., Rix H.-W., Vallenari A., Alfaro E.J., Allende Prieto C., Babusiaux C., Bensby T., Blomme R., Bragaglia A., Flaccomio E., Francois P., Hambly N., Irwin M., Korn A.J., Lanzafame A.C., Pancino E., Recio-Blanco A., Smiljanic R., Van Eck S., Walton N., Bayo A., Bergemann M., Carraro G., Costado M.T., Damiani F., Edvardsson B., Franciosini E., Frasca A., Heiter U., Hill V., Hourihane A., Jofre P., Lardo C., De Laverny P., Lind K., Magrini L., Marconi G., Martayan C., Masseron T., Monaco L., Morbidelli L., Prisinzano L., Sbordone L., Sousa S.G., Worley C.C., Zaggia S., Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Astrofísica Estelar (AE), Keele University [Keele], Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), School of Physics, Astronomy and Mathematics [Hatfield], University of Hertfordshire [Hatfield] (UH), Lund Observatory, Lund University [Lund], INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), Agence Spatiale Européenne (ESA), European Space Agency (ESA), INAF - Osservatorio Astronomico di Padova (OAPD), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Royal Observatory of Belgium [Brussels] (ROB), INAF - Osservatorio Astronomico di Bologna (OABO), Institut de Mécanique des Fluides et des Solides (IMFS), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Uppsala], Uppsala University, INAF - Osservatorio Astrofisico di Catania (OACT), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles (ULB), University of Turin, Ecole Polytechnique Fédérale de Lausanne (EPFL), Max-Planck-Institut für Astrophysik (MPA), Max-Planck-Gesellschaft, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare (INFN), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Metallicity, FOS: Physical sciences, stars: kinematics and dynamics, open clusters and associations: general, Open clusters and associations: general, Stars: kinematics and dynamics, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Spectral line, Normal distribution, Astronomi, astrofysik och kosmologi, Observatory, Astronomy, Astrophysics and Cosmology, Astrophysics::Solar and Stellar Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), kinematics and dynamics [stars], QC, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, QB, Astronomía y Astrofísica, [PHYS]Physics [physics], Physics, Very Large Telescope, Kinematics and dynamics, Astrometry, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Satellite, Astrophysics::Earth and Planetary Astrophysics, general [open clusters and associations], Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

The Gaia-ESO Survey (GES) is a large public spectroscopic survey at the European Southern Observatory Very Large Telescope. A key aim is to provide precise radial velocities (RVs) and projected equatorial velocities (v sin i) for representative samples of Galactic stars, that will complement information obtained by the Gaia astrometry satellite. We present an analysis to empirically quantify the size and distribution of uncertainties in RV and v sin i using spectra from repeated exposures of the same stars. We show that the uncertainties vary as simple scaling functions of signal-to-noise ratio (S/N) and v sin i, that the uncertainties become larger with increasing photospheric temperature, but that the dependence on stellar gravity, metallicity and age is weak. The underlying uncertainty distributions have extended tails that are better represented by Student's t-distributions than by normal distributions. Parametrised results are provided, that enable estimates of the RV precision for almost all GES measurements, and estimates of the v sin i precision for stars in young clusters, as a function of S/N, v sin i and stellar temperature. The precision of individual high S/N GES RV measurements is 0.22-0.26 km/s, dependent on instrumental configuration., 13 pages, accepted for publication in Astronomy & Astrophysics

Published
2015
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21. Gaia FGK benchmark stars: abundances of α and iron-peak elements

Author

Rosanna Sordo, Caroline Soubiran, A. Hourihane, Tristan Cantat-Gaudin, Elena Pancino, Alejandra Recio-Blanco, Carmela Lardo, L. Chemin, J. I. González Hernández, Gerry Gilmore, Ulrike Heiter, S. G. Sousa, Vardan Adibekyan, Elisa Delgado-Mena, Šarūnas Mikolaitis, S. Blanco-Cuaresma, Guillaume Guiglion, D. Montes, Maria Bergemann, Hugo M. Tabernero, Thomas Masseron, S. Van Eck, Antonella Vallenari, P. de Laverny, Clare Worley, Karin Lind, Paula Jofre, Thomas Nordlander, Laura Magrini, M2A 2015, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles (ULB), Jofre P., Heiter U., Soubiran C., Blanco-Cuaresma S., Masseron T., Nordlander T., Chemin L., Worley C.C., Van Eck S., Hourihane A., Gilmore G., Adibekyan V., Bergemann M., Cantat-Gaudin T., Delgado-Mena E., Gonzalez Hernandez J.I., Guiglion G., Lardo C., De Laverny P., Lind K., Magrini L., Mikolaitis S., Montes D., Pancino E., Recio-Blanco A., Sordo R., Sousa S., Tabernero H.M., and Vallenari A.

Subjects
Astrofísica, Milky Way, FOS: Physical sciences, Astrophysics, Spectral line, Astronomi, astrofysik och kosmologi, Abundance (ecology), stars: atmospheres, data analysis [methods], Calibration, Astronomy, Astrophysics and Cosmology, Astrophysics::Solar and Stellar Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QC, QB, atmospheres [stars], Physics, abundances [Galaxy], Astronomy and Astrophysics, Iron peak, methods: data analysis, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Galaxy: abundance, Astronomía, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Homogeneous, Benchmark (computing), Galaxy: abundances, Astrophysics::Earth and Planetary Astrophysics, Methods: data analysi
Abstract

In the current era of large spectroscopic surveys of the Milky Way, reference stars for calibrating astrophysical parameters and chemical abundances are of paramount importance. We determine elemental abundances of Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Co and Ni for our predefined set of Gaia FGK benchmark stars. By analysing high-resolution and high-signal to noise spectra taken from several archive datasets, we combined results of eight different methods to determine abundances on a line-by-line basis. We perform a detailed homogeneous analysis of the systematic uncertainties, such as differential versus absolute abundance analysis, as well as we assess errors due to NLTE and the stellar parameters in our final abundances. Our results are provided by listing final abundances and the different sources of uncertainties, as well as line-by-line and method-by-method abundances. The Gaia FGK benchmark stars atmospheric parameters are already being widely used for calibration of several pipelines applied to different surveys. With the added reference abundances of 10 elements this set is very suitable to calibrate the chemical abundances obtained by these pipelines., Comment: Accepted for publication in A&A, Printer format: 65 pages, 18 figures, 25 tables

Published
2015
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22. The Gaia-ESO Survey: the most metal-poor stars in the Galactic bulge

Author

Alejandra Recio-Blanco, David M. Nataf, Sofia Randich, Karin Lind, A. Hourihane, Carmela Lardo, Sofia Feltzing, G. G. Sacco, Martin Asplund, C. C. Worley, Paula Jofre, Andreas Korn, David Yong, C. Allende Prieto, L. M. Howes, G. S. Da Costa, Enrico Maiorca, Manuela Zoccali, Francesco Damiani, L. Morbidelli, Vanessa Hill, Maria Bergemann, Ulrike Heiter, Andrew R. Casey, Rodolfo Smiljanic, Gerard Gilmore, Stefan Keller, Michael S. Bessell, Dante Minniti, Patrick Tisserand, Laura Magrini, Anna F. Marino, Brian P. Schmidt, Antonella Vallenari, Thomas Masseron, Luca Casagrande, Ettore Flaccomio, P. de Laverny, Elena Pancino, Thomas Bensby, Christopher Owen, M. T. Costado, Howes L.M., Asplund M., Casey A.R., Keller S.C., Yong D., Gilmore G., Lind K., Worley C., Bessell M.S., Casagrande L., Marino A.F., Nataf D.M., Owen C.I., Da Costa G.S., Schmidt B.P., Tisserand P., Randich S., Feltzing S., Vallenari A., Allende Prieto C., Bensby T., Flaccomio E., Korn A.J., Pancino E., Recio-Blanco A., Smiljanic R., Bergemann M., Costado M.T., Damiani F., Heiter U., Hill V., Hourihane A., Jofre P., Lardo C., de Laverny P., Magrini L., Maiorca E., Masseron T., Morbidelli L., Sacco G.G., Minniti D., and Zoccali M.

Subjects
010504 meteorology & atmospheric sciences, Evolution, Metallicity, K-type main-sequence star, Milky Way, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Bulge, 0103 physical sciences, Galaxy formation and evolution, Population II-Galaxy, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Physics, Spiral galaxy, Bulge-Galaxy, Astronomy, Astronomy and Astrophysics, Stars, Astrophysics - Astrophysics of Galaxies, Galaxy, Abundances-star, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics
Abstract

We present the first results of the EMBLA survey (Extremely Metal-poor BuLge stars with AAOmega), aimed at finding metal-poor stars in the Milky Way bulge, where the oldest stars should now preferentially reside. EMBLA utilises SkyMapper photometry to pre-select metal-poor candidates, which are subsequently confirmed using AAOmega spectroscopy. We describe the discovery and analysis of four bulge giants with -2.72, Comment: 7 pages, 5 figures. Accepted for publication by MNRAS

Published
2014
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23. The Gaia-ESO Survey: Stellar content and elemental abundances in the massive cluster NGC 6705

Author

Douglas Geisler, Paula Jofre, Thomas Bensby, A. Hourihane, A. Kupcu-Yoldas, Gerard Gilmore, F. M. Jiménez-Esteban, Robert Greimel, L. Prisinzano, E. Puzeras, E. A. Gonzalez-Solares, Ettore Flaccomio, Carmela Lardo, Arnas Drazdauskas, P. Donati, Tristan Cantat-Gaudin, Alejandra Recio-Blanco, A. Klutsch, A. C. Lanzafame, I. San, L. Sampedro, Luca Sbordone, Emilio J. Alfaro, Enrico Maiorca, L. Balaguer-Núñez, S. Villanova, Elena Pancino, Simone Zaggia, Despina Hatzidimitriou, H. J. Farnhill, Laura Magrini, J. Eisloeffel, Rodolfo Smiljanic, Antonella Vallenari, Angela Bragaglia, A. Spagna, Ummi Abbas, Monica Tosi, R. Blomme, Heather R. Jacobson, Alberto Vecchiato, Clare Worley, G. G. Sacco, L. Morbidelli, Mike Irwin, Janet E. Drew, R. Sordo, Thomas Masseron, Carme Jordi, Sofia Randich, Grazina Tautvaisiene, Francesco Damiani, P. deLaverny, M. T. Costado, Eileen D. Friel, Cantat-Gaudin T., Vallenari A., Zaggia S., Bragaglia A., Sordo R., Drew J.E., Eisloeffel J., Farnhill H.J., Gonzalez-Solares E., Greimel R., Irwin M.J., Kupcu-Yoldas A., Jordi C., Blomme R., Sampedro L., Costado M.T., Alfaro E., Smiljanic R., Magrini L., Donati P., Friel E.D., Jacobson H., Abbas U., Hatzidimitriou D., Spagna A., Vecchiato A., Balaguer-Nunez L., Lardo C., Tosi M., Pancino E., Klutsch A., Tautvaisiene G., Drazdauskas A., Puzeras E., Jimenez-Esteban F., Maiorca E., Geisler D., San Roman I., Villanova S., Gilmore G., Randich S., Bensby T., Flaccomio E., Lanzafame A., Recio-Blanco A., Damiani F., Hourihane A., Jofre P., De Laverny P., Masseron T., Morbidelli L., Prisinzano L., Sacco G.G., Sbordone L., and Worley C.C.

Subjects
Physics, 010308 nuclear & particles physics, Milky Way, Metallicity, Stars: abundances, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Open clusters and associations: general, 01 natural sciences, Open clusters and associations: individual: NGC 6705, Photometry (optics), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Globular cluster, 0103 physical sciences, Cluster (physics), Mass segregation, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Red clump, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Open cluster
Abstract

Context. Chemically inhomogeneous populations are observed in most globular clusters, but not in open clusters. Cluster mass seems to play a key role in the existence of multiple populations. Aims. Studying the chemical homogeneity of the most massive open clusters is needed to better understand the mechanism of their formation and determine the mass limit under which clusters cannot host multiple populations. Here we studied NGC≠6705, which is a young and massive open cluster located towards the inner region of the Milky Way. This cluster is located inside the solar circle. This makes it an important tracer of the inner disk abundance gradient. Methods. This study makes use of BVI and ri photometry and comparisons with theoretical isochrones to derive the age of NGC≠6705. We study the density profile of the cluster and the mass function to infer the cluster mass. Based on abundances of the chemical elements distributed in the first internal data release of the Gaia-ESO Survey, we study elemental ratios and the chemical homogeneity of the red clump stars. Radial velocities enable us to study the rotation and internal kinematics of the cluster. Results. The estimated ages range from 250 to 316≠Myr, depending on the adopted stellar model. Luminosity profiles and mass functions show strong signs of mass segregation. We derive the mass of the cluster from its luminosity function and from the kinematics, finding values between 3700 M and 11 000 M. After selecting the cluster members from their radial velocities, we obtain a metallicity of [Fe/H] = 0.10 ± 0.06 based on 21 candidate members. Moreover, NGC 6705 shows no sign of the typical correlations or anti-correlations between Al, Mg, Si, and Na, which are expected in multiple populations. This is consistent with our cluster mass estimate, which is lower than the required mass limit proposed in the literature to develop multiple populations.

Published
2014

24. TheGaia-ESO Survey: Kinematics of seven Galactic globular clusters

Author

Carmela Lardo, Sofia Feltzing, Alejandra Recio-Blanco, Elena Pancino, Maria Bergemann, Michele Bellazzini, C. Allende Prieto, Thomas Masseron, Sofia Randich, G. G. Sacco, Gerard Gilmore, R. D. Jeffries, Paolo Donati, Giovanni Carraro, Emilio J. Alfaro, Sergey E. Koposov, M. T. Costado, Francesco Damiani, L. Morbidelli, A. Hourihane, Angela Bragaglia, Paula Jofre, Ettore Flaccomio, Gianni Marconi, Antonella Vallenari, P. de Laverny, Clare Worley, Lardo C., Pancino E., Bellazzini M., Bragaglia A., Donati P., Gilmore G., Randich S., Feltzing S., Jeffries R.D., Vallenari A., Alfaro E.J., Allende Prieto C., Flaccomio E., Koposov S.E., Recio-Blanco A., Bergemann M., Carraro G., Costado M.T., Damiani F., Hourihane A., Jofre P., De Laverny P., Marconi G., Masseron T., Morbidelli L., Sacco G.G., Worley C.C., ITA, GBR, FRA, DEU, ESP, and SWE

Subjects
Physics, astro-ph.GA, Milky Way, FOS: Physical sciences, Velocity dispersion, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Kinematics, Astrophysics - Astrophysics of Galaxies, Galaxy, Radial velocity, Stars, General, Globular clusters, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Globular cluster, Cluster (physics), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, QC, Astrophysics::Galaxy Astrophysics, QB
Abstract

The Gaia-ESO survey is a large public spectroscopic survey aimed at investigating the origin and formation history of our Galaxy by collecting spectroscopy of representative samples (about 10^5 Milky Way stars) of all Galactic stellar populations, in the field and in clusters. The survey uses globular clusters as intra- and inter-survey calibrators, deriving stellar atmospheric parameters and abundances of a significant number of stars in clusters, along with radial velocity determinations. We used precise radial velocities of a large number of stars in seven globular clusters (NGC 1851, NGC 2808, NGC 4372, NGC 4833, NGC 5927, NGC 6752, and NGC 7078) to validate pipeline results and to preliminarily investigate the cluster internal kinematics. Radial velocity measurements were extracted from FLAMES/GIRAFFE spectra processed by the survey pipeline as part of the second internal data release of data products to ESO. We complemented our sample with ESO archival data obtained with different instrument configurations. Reliable radial velocity measurements for 1513 bona fide cluster star members were obtained in total. We measured systemic rotation, estimated central velocity dispersions, and present velocity dispersion profiles of all the selected clusters, providing the first velocity dispersion curve and the first estimate of the central velocity dispersion for the cluster NGC~5927. Finally, we explore the possible link between cluster kinematics and other physical parameters. The analysis we present here demonstrates that Gaia-ESO survey data are sufficiently accurate to be used in studies of kinematics of stellar systems and stellar populations in the Milky Way., Comment: 10 pages, 5 tables, 18 figures. Accepted to A&A

Published
2015
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25. TheGaia-ESO Survey: radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk

Author

M. Bergemann, G. R. Ruchti, A. Serenelli, S. Feltzing, A. Alves-Brito, M. Asplund, T. Bensby, P. Gruiters, U. Heiter, A. Hourihane, A. Korn, K. Lind, A. Marino, P. Jofre, T. Nordlander, N. Ryde, C. C. Worley, G. Gilmore, S. Randich, A. M. N. Ferguson, R. D. Jeffries, G. Micela, I. Negueruela, T. Prusti, H.-W. Rix, A. Vallenari, E. J. Alfaro, C. Allende Prieto, A. Bragaglia, S. E. Koposov, A. C. Lanzafame, E. Pancino, A. Recio-Blanco, R. Smiljanic, N. Walton, M. T. Costado, E. Franciosini, V. Hill, C. Lardo, P. de Laverny, L. Magrini, E. Maiorca, T. Masseron, L. Morbidelli, G. Sacco, G. Kordopatis, G. Tautvaišienė, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Astrofísica Estelar (AE), Bergemann M., Ruchti G.R., Serenelli A., Feltzing S., Alves-Brito A., Asplund M., Bensby T., Gruiters P., Heiter U., Hourihane A., Korn A., Lind K., Marino A., Jofre P., Nordlander T., Ryde N., Worley C.C., Gilmore G., Randich S., Ferguson A.M.N., Jeffries R.D., Micela G., Negueruela I., Prusti T., Rix H.-W., Vallenari A., Alfaro E.J., Allende Prieto C., Bragaglia A., Koposov S.E., Lanzafame A.C., Pancino E., Recio-Blanco A., Smiljanic R., Walton N., Costado M.T., Franciosini E., Hill V., Lardo C., De Laverny P., Magrini L., Maiorca E., Masseron T., Morbidelli L., Sacco G., Kordopatis G., and Tautvaisiene G.

Subjects
Solar neighborhood, Milky Way, Metallicity, Formation, FOS: Physical sciences, Galaxia, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Surveys, fundamental parameters [Stars], Astronomia ultravioleta, 01 natural sciences, Spectral line, Galaxy: disk, Stars:fundamental parameter, Fundamental parameters, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Abundances, Disc, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Astronomía y Astrofísica, Mapeamentos astronômicos, Physics, 010308 nuclear & particles physics, Plane (geometry), Stars:abundance, Vertical distance, Astronomy and Astrophysics, Composicao estelar, Astrophysics - Astrophysics of Galaxies, Espectros estelares, Stars, Galaxy, formation [Galaxy], Galaxy: formation, Disk, Space and Planetary Science, abundances [Stars], Astrophysics of Galaxies (astro-ph.GA), Magnitude (astronomy), Astrophysics::Earth and Planetary Astrophysics, disk [Galaxy]
Abstract

We study the relationship between age, metallicity, and alpha-enhancement of FGK stars in the Galactic disk. The results are based upon the analysis of high-resolution UVES spectra from the Gaia-ESO large stellar survey. We explore the limitations of the observed dataset, i.e. the accuracy of stellar parameters and the selection effects that are caused by the photometric target preselection. We find that the colour and magnitude cuts in the survey suppress old metal-rich stars and young metal-poor stars. This suppression may be as high as 97% in some regions of the age-metallicity relationship. The dataset consists of 144 stars with a wide range of ages from 0.5 Gyr to 13.5 Gyr, Galactocentric distances from 6 kpc to 9.5 kpc, and vertical distances from the plane 0 < |Z| < 1.5 kpc. On this basis, we find that i) the observed age-metallicity relation is nearly flat in the range of ages between 0 Gyr and 8 Gyr; ii) at ages older than 9 Gyr, we see a decrease in [Fe/H] and a clear absence of metal-rich stars; this cannot be explained by the survey selection functions; iii) there is a significant scatter of [Fe/H] at any age; and iv) [Mg/Fe] increases with age, but the dispersion of [Mg/Fe] at ages > 9 Gyr is not as small as advocated by some other studies. In agreement with earlier work, we find that radial abundance gradients change as a function of vertical distance from the plane. The [Mg/Fe] gradient steepens and becomes negative. In addition, we show that the inner disk is not only more alpha-rich compared to the outer disk, but also older, as traced independently by the ages and Mg abundances of stars., accepted for publication in A&A

Published
2014
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