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151. Holistic spectroscopy: complete reconstruction of a wide-field, multiobject spectroscopic image using a photonic comb

Author

Kos, Janez, primary, Bland-Hawthorn, Joss, additional, Betters, Christopher H, additional, Leon-Saval, Sergio, additional, Asplund, Martin, additional, Buder, Sven, additional, Casey, Andrew R, additional, D’Orazi, Valentina, additional, de Silva, Gayandhi, additional, Freeman, Ken, additional, Lewis, Geraint, additional, Lin, Jane, additional, Martell, Sarah L, additional, Schlesinger, Katharine, additional, Sharma, Sanjib, additional, Simpson, Jeffrey D, additional, Zucker, Daniel, additional, Zwitter, Tomaž, additional, Hayden, Michael, additional, Horner, Jonathan, additional, Nataf, David M, additional, and Ting, Yuan-Sen, additional

Published
2018
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152. The GALAH survey : verifying abundance trends in the open cluster M67 using non-LTE modelling

Author

Gao, Xudong, Lind, Karin, Amarsi, Anish M., Buder, Sven, Dotter, Aaron, Nordlander, Thomas, Asplund, Martin, Bland-Hawthorn, Joss, De Silva, Gayandhi M., D'Orazi, Valentina, Freeman, Ken C., Kos, Janez, Lewis, Geraint F., Lin, Jane, Martell, Sarah L., Schlesinger, Katharine J., Sharma, Sanjib, Simpson, Jeffrey D., Zucker, Daniel B., Zwitter, Tomaz, Da Costa, Gary, Anguiano, Borja, Horner, Jonathan, Hyde, Elaina A., Kafle, Prajwal R., Nataf, David M., Reid, Warren, Stello, Dennis, Ting, Yuan-Sen, Gao, Xudong, Lind, Karin, Amarsi, Anish M., Buder, Sven, Dotter, Aaron, Nordlander, Thomas, Asplund, Martin, Bland-Hawthorn, Joss, De Silva, Gayandhi M., D'Orazi, Valentina, Freeman, Ken C., Kos, Janez, Lewis, Geraint F., Lin, Jane, Martell, Sarah L., Schlesinger, Katharine J., Sharma, Sanjib, Simpson, Jeffrey D., Zucker, Daniel B., Zwitter, Tomaz, Da Costa, Gary, Anguiano, Borja, Horner, Jonathan, Hyde, Elaina A., Kafle, Prajwal R., Nataf, David M., Reid, Warren, Stello, Dennis, and Ting, Yuan-Sen

Abstract

Open cluster members are coeval and share the same initial bulk chemical composition. Consequently, differences in surface abundances between members of a cluster that are at different evolutionary stages can be used to study the effects of mixing and internal chemical processing. We carry out an abundance analysis of seven elements (Li, O, Na, Mg, Al, Si, and Fe) in 66 stars belonging to the open cluster m67, based on high resolution GALAH spectra, 1D MARCS model atmospheres, and non-local thermodynamic equilibrium (non-LTE) radiative transfer. From the non-LTE analysis, we find a typical star-to-star scatter in the abundance ratios of around O.05 dex. We find trends in the abundance ratios with effective temperature, indicating systematic differences in the surface abundances between turn-off and giant stars; these trends are more pronounced when LTE is assumed. However, trends with effective temperature remain significant for Al and Si also in non-LTE. Finally, we compare the derived abundances with prediction from stellar evolution models including effects of atomic diffusion. We find overall good agreement for the abundance patterns of dwarfs and sub-giant stars, but the abundances of cool giants are lower relative to less evolved stars than predicted by the diffusion models, in particular for Mg.

Published
2018
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153. The GALAH Survey : second data release

Author

Buder, Sven, Asplund, Martin, Duong, Ly, Kos, Janez, Lind, Karin, Ness, Melissa K., Sharma, Sanjib, Bland-Hawthorn, Joss, Casey, Andrew R., De Silva, Gayandhi M., D'Orazi, Valentina, Freeman, Ken C., Lewis, Geraint F., Lin, Jane, Martell, Sarah L., Schlesinger, Katharine J., Simpson, Jeffrey D., Zucker, Daniel B., Zwitter, Tomaz, Amarsi, Anish M., Anguiano, Borja, Carollo, Daniela, Casagrande, Luca, Cotar, Klemen, Cottrell, Peter L., Da Costa, Gary, Gao, Xudong D., Hayden, Michael R., Horner, Jonathan, Ireland, Michael J., Kafle, Prajwal R., Munari, Ulisse, Nataf, David M., Nordlander, Thomas, Stello, Dennis, Ting, Yuan-Sen, Traven, Gregor, Watson, Fred, Wittenmyer, Robert A., Wyse, Rosemary F. G., Yong, David, Zinn, Joel C., Zerjal, Marusa, Buder, Sven, Asplund, Martin, Duong, Ly, Kos, Janez, Lind, Karin, Ness, Melissa K., Sharma, Sanjib, Bland-Hawthorn, Joss, Casey, Andrew R., De Silva, Gayandhi M., D'Orazi, Valentina, Freeman, Ken C., Lewis, Geraint F., Lin, Jane, Martell, Sarah L., Schlesinger, Katharine J., Simpson, Jeffrey D., Zucker, Daniel B., Zwitter, Tomaz, Amarsi, Anish M., Anguiano, Borja, Carollo, Daniela, Casagrande, Luca, Cotar, Klemen, Cottrell, Peter L., Da Costa, Gary, Gao, Xudong D., Hayden, Michael R., Horner, Jonathan, Ireland, Michael J., Kafle, Prajwal R., Munari, Ulisse, Nataf, David M., Nordlander, Thomas, Stello, Dennis, Ting, Yuan-Sen, Traven, Gregor, Watson, Fred, Wittenmyer, Robert A., Wyse, Rosemary F. G., Yong, David, Zinn, Joel C., and Zerjal, Marusa

Abstract

The Galactic Archaeology with HERMES (GALAH) survey is a large-scale stellar spectroscopic survey of the Milky Way, designed to deliver complementary chemical information to a large number of stars covered by the Gaia mission. We present the GALAH second public data release (GALAH DR2) containing 342 682 stars. For these stars, the GALAH collaboration provides stellar parameters and abundances for up to 23 elements to the community. Here we present the target selection, observation, data reduction, and detailed explanation of how the spectra were analysed to estimate stellar parameters and element abundances. For the stellar analysis, we have used a multistep approach. We use the physics-driven spectrum synthesis of Spectroscopy Made Easy (SME) to derive stellar labels (T-eff, log g, [Fe/H], [X/Fe], v(mic), vsin i, AKS) for a representative training set of stars. This information is then propagated to the whole sample with the data-driven method of The Cannon. Special care has been exercised in the spectral synthesis to only consider spectral lines that have reliable atomic input data and are little affected by blending lines. Departures from local thermodynamic equilibrium (LTE) are considered for several key elements, including Li, O, Na, Mg, Al, Si, and Fe, using 1D MARCS stellar atmosphere models. Validation tests including repeat observations, Gaia benchmark stars, open and globular clusters, and K2 asteroseismic targets lend confidence to our methods and results. Combining the GALAH DR2 catalogue with the kinematic information from Gaia will enable a wide range of Galactic Archaeology studies, with unprecedented detail, dimensionality, and scope.

Published
2018
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154. The GALAH survey and Gaia DR2 : (non-)existence of five sparse high-latitude open clusters

Author

Kos, Janez, de Silva, Gayandhi, Buder, Sven, Bland-Hawthorn, Joss, Sharma, Sanjib, Asplund, Martin, D'Orazi, Valentina, Duong, Ly, Freeman, Ken, Lewis, Geraint F., Lin, Jane, Lind, Karin, Martell, Sarah L., Schlesinger, Katharine J., Simpson, Jeffrey D., Zucker, Daniel B., Zwitter, Tomaz, Bedding, Timothy R., Cotar, Klemen, Horner, Jonathan, Nordlander, Thomas, Stello, Denis, Ting, Yuan-Sen, Traven, Gregor, Kos, Janez, de Silva, Gayandhi, Buder, Sven, Bland-Hawthorn, Joss, Sharma, Sanjib, Asplund, Martin, D'Orazi, Valentina, Duong, Ly, Freeman, Ken, Lewis, Geraint F., Lin, Jane, Lind, Karin, Martell, Sarah L., Schlesinger, Katharine J., Simpson, Jeffrey D., Zucker, Daniel B., Zwitter, Tomaz, Bedding, Timothy R., Cotar, Klemen, Horner, Jonathan, Nordlander, Thomas, Stello, Denis, Ting, Yuan-Sen, and Traven, Gregor

Abstract

Sparse open clusters can be found at high galactic latitudes where loosely populated clusters are more easily detected against the lower stellar background. Because most star formation takes place in the thin disc, the observed population of clusters far from the Galactic plane is hard to explain. We combined spectral parameters from the GALAH survey with the Gaia DR2 catalogue to study the dynamics and chemistry of five old sparse high-latitude clusters in more detail. We find that four of them (NGC 1252, NGC 6994, NGC 7772, NGC 7826) - originally classified in 1888 - are not clusters but are instead chance projections on the sky. Member stars quoted in the literature for these four clusters are unrelated in our multidimensional physical parameter space; the quoted cluster properties in the literature are therefore meaningless. We confirm the existence of visually similar NGC 1901 for which we provide a probabilistic membership analysis. An overdensity in three spatial dimensions proves to be enough to reliably detect sparse clusters, but the whole six-dimensional space must be used to identify members with high confidence, as demonstrated in the case of NGC 1901.

Published
2018
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157. Identifying stellar streams in Gaia DR2 with data mining techniques.

Author

Borsato, Nicholas W, Martell, Sarah L, and Simpson, Jeffrey D

Subjects
DATA mining, BIG data, RIVERS, GLOBULAR clusters, PHASE space
Abstract

Streams of stars from captured dwarf galaxies and dissolved globular clusters are identifiable through the similarity of their orbital parameters, a fact that remains true long after the streams have dispersed spatially. We calculate the integrals of motion for 31 234 stars, to a distance of 4 kpc from the Sun, which have full and accurate 6D phase space positions in the Gaia DR2 catalogue. We then apply a novel combination of data mining, numerical, and statistical techniques to search for stellar streams. This process returns five high confidence streams (including one which was previously undiscovered), all of which display tight clustering in the integral of motion space. Colour–magnitude diagrams indicate that these streams are relatively simple, old, metal-poor populations. One of these resolved streams shares very similar kinematics and metallicity characteristics with the Gaia-Enceladus dwarf galaxy remnant, but with a slightly younger age. The success of this project demonstrates the usefulness of data mining techniques in exploring large data sets. [ABSTRACT FROM AUTHOR]

Published
2020
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158. The GALAH Survey: Chemically tagging the Fimbulthul stream to the globular cluster ω Centauri.

Author

Simpson, Jeffrey D, Martell, Sarah L, Da Costa, Gary, Horner, Jonathan, Wyse, Rosemary F G, Ting, Yuan-Sen, Asplund, Martin, Bland-Hawthorn, Joss, Buder, Sven, De Silva, Gayandhi M, Freeman, Ken C, Kos, Janez, Lewis, Geraint F, Lind, Karin, Sharma, Sanjib, Zucker, Daniel B, Zwitter, Tomaž, Čotar, Klemen, Cottrell, Peter L, and Nordlander, Thomas

Subjects
GLOBULAR clusters, RIVERS, MILKY Way
Abstract

Using kinematics from Gaia and the large elemental abundance space of the second data release of the GALAH survey, we identify two new members of the Fimbulthul stellar stream, and chemically tag them to massive, multimetallic globular cluster ω Centauri. Recent analysis of the second data release of Gaia had revealed the Fimbulthul stellar stream in the halo of the Milky Way. It had been proposed that the stream is associated with the ω Cen, but this proposition relied exclusively upon the kinematics and metallicities of the stars to make the association. In this work, we find our two new members of the stream to be metal-poor stars that are enhanced in sodium and aluminium, typical of second population globular cluster stars, but not otherwise seen in field stars. Furthermore, the stars share the s-process abundance pattern seen in ω Cen, which is rare in field stars. Apart from one star within 1.5 deg of ω Cen, we find no other stars observed by GALAH spatially near ω Cen or the Fimbulthul stream that could be kinematically and chemically linked to the cluster. Chemically tagging stars in the Fimbulthul stream to ω Cen confirms the earlier work, and further links this tidal feature in the Milky Way halo to ω Cen. [ABSTRACT FROM AUTHOR]

Published
2020
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159. Discovery of a nearby 1700 km s−1 star ejected from the Milky Way by Sgr A.

Author

Koposov, Sergey E, Boubert, Douglas, Li, Ting S, Erkal, Denis, Da Costa, Gary S, Zucker, Daniel B, Ji, Alexander P, Kuehn, Kyler, Lewis, Geraint F, Mackey, Dougal, Simpson, Jeffrey D, Shipp, Nora, Wan, Zhen, Belokurov, Vasily, Bland-Hawthorn, Joss, Martell, Sarah L, Nordlander, Thomas, Pace, Andrew B, De Silva, Gayandhi M, and Wang, Mei-Yu

Subjects
MILKY Way, STELLAR parallax, MAIN sequence (Astronomy), STELLAR orbits, STELLAR dynamics
Abstract

We present the serendipitous discovery of the fastest main-sequence hyper-velocity star (HVS) by the Southern Stellar Stream Spectroscopic Survey (S5). The star S5-HVS1 is a ∼2.35 M⊙ A-type star located at a distance of ∼9 kpc from the Sun and has a heliocentric radial velocity of 1017 ± 2.7  |$\mathrm{\, km\, s^{-1}}$| without any signature of velocity variability. The current 3D velocity of the star in the Galactic frame is 1755 ± 50  |$\mathrm{\, km\, s^{-1}}$|⁠. When integrated backwards in time, the orbit of the star points unambiguously to the Galactic Centre, implying that S5-HVS1 was kicked away from Sgr A* with a velocity of ∼1800  |$\mathrm{\, km\, s^{-1}}$| and travelled for 4.8 Myr to its current location. This is so far the only HVS confidently associated with the Galactic Centre. S5-HVS1 is also the first hyper-velocity star to provide constraints on the geometry and kinematics of the Galaxy, such as the Solar motion V y ,⊙ = 246.1 ± 5.3  |$\mathrm{\, km\, s^{-1}}$| or position R 0 = 8.12 ± 0.23 kpc. The ejection trajectory and transit time of S5-HVS1 coincide with the orbital plane and age of the annular disc of young stars at the Galactic Centre, and thus may be linked to its formation. With the S5-HVS1 ejection velocity being almost twice the velocity of other hyper-velocity stars previously associated with the Galactic Centre, we question whether they have been generated by the same mechanism or whether the ejection velocity distribution has been constant over time. [ABSTRACT FROM AUTHOR]

Published
2020
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160. GALAH survey: unresolved triple Sun-like stars discovered by the Gaia mission.

Author

Čotar, Klemen, Zwitter, Tomaž, Traven, Gregor, Kos, Janez, Asplund, Martin, Bland-Hawthorn, Joss, Buder, Sven, D'Orazi, Valentina, De Silva, Gayandhi M, Lin, Jane, Martell, Sarah L, Sharma, Sanjib, Simpson, Jeffrey D, Zucker, Daniel B, Horner, Jonathan, Lewis, Geraint F, Nordlander, Thomas, Ting, Yuan-Sen, Wittenmyer, Rob A, and GALAH collaboration

Subjects
STELLAR spectra, STARS, BINARY stars, CORRECTION factors, SOLAR spectra
Abstract

The latest Gaia data release enables us to accurately identify stars that are more luminous than would be expected on the basis of their spectral type and distance. During an investigation of the 329 best solar twin candidates uncovered among the spectra acquired by the GALAH survey, we identified 64 such overluminous stars. In order to investigate their exact composition, we developed a data-driven methodology that can generate a synthetic photometric signature and spectrum of a single star. By combining multiple such synthetic stars into an unresolved binary or triple system and comparing the results to the actual photometric and spectroscopic observations, we uncovered 6 definitive triple stellar system candidates and an additional 14 potential candidates whose combined spectrum mimics the solar spectrum. Considering the volume correction factor for a magnitude-limited survey, the fraction of probable unresolved triple stars with long orbital periods is ∼2 per cent. Possible orbital configurations of the candidates were investigated using the selection and observational limits. To validate the discovered multiplicity fraction, the same procedure was used to evaluate the multiplicity fraction of other stellar types. [ABSTRACT FROM AUTHOR]

Published
2019
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161. GALAH survey and Gaia DR2: dissecting the stellar disc's phase space by age, action, chemistry, and location.

Author

Bland-Hawthorn, Joss, Sharma, Sanjib, Tepper-Garcia, Thor, Binney, James, Freeman, Ken C, Hayden, Michael R, Kos, Janez, De Silva, Gayandhi M, Ellis, Simon, Lewis, Geraint F, Asplund, Martin, Buder, Sven, Casey, Andrew R, D'Orazi, Valentina, Duong, Ly, Khanna, Shourya, Lin, Jane, Lind, Karin, Martell, Sarah L, and Ness, Melissa K

Subjects
PHASE space, ASTROMETRY, CHEMISTRY, DISK galaxies, DISTRIBUTION of stars, STELLAR dynamics
Abstract

We use the second data releases of the European Space Agency Gaia astrometric survey and the high-resolution Galactic Archaeology with HERMES (GALAH) spectroscopic survey to analyse the structure of our Galaxy's disc components. With GALAH, we separate the α-rich and α-poor discs (with respect to Fe), which are superposed in both position and velocity space, and examine their distributions in action space. We study the distribution of stars in the zV |$\mathrm{ z}$| phase plane, for both V ϕ and VR, and recover the remarkable 'phase spiral' discovered by Gaia. We identify the anticipated quadrupole signature in zV |$\mathrm{ z}$| of a tilted velocity ellipsoid for stars above and below the Galactic plane. By connecting our work with earlier studies, we show that the phase spiral is likely to extend well beyond the narrow solar neighbourhood cylinder in which it was found. The phase spiral is a signature of corrugated waves that propagate through the disc, and the associated non-equilibrium phase mixing. The radially asymmetric distribution of stars involved in the phase spiral reveals that the corrugation, which is mostly confined to the α-poor disc, grows in z -amplitude with increasing radius. We present new simulations of tidal disturbance of the Galactic disc by the Sagittarius (Sgr) dwarf. The effect on the zV |$\mathrm{ z}$| phase plane lasts |${\gtrsim } 2\, \mathrm{Gyr}$|⁠, but a subsequent disc crossing wipes out the coherent structure. We find that the phase spiral was excited |${\lesssim } 0.5\, \mathrm{Gyr}$| ago by an object like Sgr with total mass ∼3 × 1010 M⊙ (stripped down from ∼5 × 1010 M⊙ when it first entered the halo) passing through the plane. [ABSTRACT FROM AUTHOR]

Published
2019
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162. The GALAH Survey and Galactic Archaeology in the Next Decade

Author

Skillen, I, Balcells, M, Trager, SC, Martell, Sarah L ; https://orcid.org/0000-0002-3430-4163, Skillen, I, Balcells, M, Trager, SC, and Martell, Sarah L ; https://orcid.org/0000-0002-3430-4163

Abstract

The field of Galactic Archaeology aims to understand the origins and evolution of the stellar populations in the Milky Way, as a way to understand galaxy formation and evolution in general. The GALAH (Galactic Archaeology with HERMES) Survey is an ambitious Australian-led project to explore the Galactic history of star formation, chemical evolution, minor mergers and stellar migration. GALAH is using the HERMES spectrograph, a novel, highly multiplexed, four-channel high-resolution optical spectrograph, to collect high-quality R ~ 28,000 spectra for one million stars in the Milky Way. From these data we will determine stellar parameters, radial velocities and abundances for up to 29 elements per star, and carry out a thorough chemical tagging study of the nearby Galaxy. There are clear complementarities between GALAH and other ongoing and planned Galactic Archaeology surveys, and also with ancillary stellar data collected by of major cosmological surveys. Combined, these data sets will provide a revolutionary view of the structure and history of the Milky Way.

Published
2016

163. CHEMICAL TAGGING CAN WORK: IDENTIFICATION OF STELLAR PHASE-SPACE STRUCTURES PURELY BY CHEMICAL-ABUNDANCE SIMILARITY

Author

Hogg, David W., primary, Casey, Andrew R., additional, Ness, Melissa, additional, Rix, Hans-Walter, additional, Foreman-Mackey, Daniel, additional, Hasselquist, Sten, additional, Ho, Anna Y. Q., additional, Holtzman, Jon A., additional, Majewski, Steven R., additional, Martell, Sarah L., additional, Mészáros, Szabolcs, additional, Nidever, David L., additional, and Shetrone, Matthew, additional

Published
2016
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164. APOGEE chemical abundances of globular cluster giants in the inner Galaxy

Author

Schiavon, Ricardo P., primary, Johnson, Jennifer A., additional, Frinchaboy, Peter M., additional, Zasowski, Gail, additional, Mészáros, Szabolcs, additional, García-Hernández, D. A., additional, Cohen, Roger E., additional, Tang, Baitian, additional, Villanova, Sandro, additional, Geisler, Douglas, additional, Beers, Timothy C., additional, Fernández-Trincado, J. G., additional, García Pérez, Ana E., additional, Lucatello, Sara, additional, Majewski, Steven R., additional, Martell, Sarah L., additional, O'Connell, Robert W., additional, Prieto, Carlos Allende, additional, Bizyaev, Dmitry, additional, Carrera, Ricardo, additional, Lane, Richard R., additional, Malanushenko, Elena, additional, Malanushenko, Viktor, additional, Muñoz, Ricardo R., additional, Nitschelm, Christian, additional, Oravetz, Daniel, additional, Pan, Kaike, additional, Roman-Lopes, Alexandre, additional, Schultheis, Matthias, additional, and Simmons, Audrey, additional

Published
2016
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167. Chemical tagging with APOGEE: discovery of a large population of N-rich stars in the inner Galaxy

Author

Schiavon, Ricardo P., primary, Zamora, Olga, additional, Carrera, Ricardo, additional, Lucatello, Sara, additional, Robin, A. C., additional, Ness, Melissa, additional, Martell, Sarah L., additional, Smith, Verne V., additional, García-Hernández, D. A., additional, Manchado, Arturo, additional, Schönrich, Ralph, additional, Bastian, Nate, additional, Chiappini, Cristina, additional, Shetrone, Matthew, additional, Mackereth, J. Ted, additional, Williams, Rob A., additional, Mészáros, Szabolcs, additional, Allende Prieto, Carlos, additional, Anders, Friedrich, additional, Bizyaev, Dmitry, additional, Beers, Timothy C., additional, Chojnowski, S. Drew, additional, Cunha, Katia, additional, Epstein, Courtney, additional, Frinchaboy, Peter M., additional, García Pérez, Ana E., additional, Hearty, Fred R., additional, Holtzman, Jon A., additional, Johnson, Jennifer A., additional, Kinemuchi, Karen, additional, Majewski, Steven R., additional, Muna, Demitri, additional, Nidever, David L., additional, Nguyen, Duy Cuong, additional, O'Connell, Robert W., additional, Oravetz, Daniel, additional, Pan, Kaike, additional, Pinsonneault, Marc, additional, Schneider, Donald P., additional, Schultheis, Matthias, additional, Simmons, Audrey, additional, Skrutskie, Michael F., additional, Sobeck, Jennifer, additional, Wilson, John C., additional, and Zasowski, Gail, additional

Published
2016
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168. The GALAH survey: the data reduction pipeline

Author

Kos, Janez, primary, Lin, Jane, additional, Zwitter, Tomaž, additional, Žerjal, Maruška, additional, Sharma, Sanjib, additional, Bland-Hawthorn, Joss, additional, Asplund, Martin, additional, Casey, Andrew R., additional, De Silva, Gayandhi M., additional, Freeman, Ken C., additional, Martell, Sarah L., additional, Simpson, Jeffrey D., additional, Schlesinger, Katharine J., additional, Zucker, Daniel, additional, Anguiano, Borja, additional, Bacigalupo, Carlos, additional, Bedding, Timothy R., additional, Betters, Christopher, additional, Da Costa, Gary, additional, Duong, Ly, additional, Hyde, Elaina, additional, Ireland, Michael, additional, Kafle, Prajwal R., additional, Leon-Saval, Sergio, additional, Lewis, Geraint F., additional, Munari, Ulisse, additional, Nataf, David, additional, Stello, Dennis, additional, Tinney, C. G., additional, Traven, Gregor, additional, Watson, Fred, additional, and Wittenmyer, Robert A., additional

Published
2016
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170. GALAH survey: a catalogue of carbon-enhanced stars and CEMP candidates.

Author

Čotar, Klemen, Zwitter, Tomaž, Kos, Janez, Munari, Ulisse, Martell, Sarah L, Asplund, Martin, Bland-Hawthorn, Joss, Buder, Sven, De Silva, Gayandhi M, Freeman, Kenneth C, Sharma, Sanjib, Anguiano, Borja, Carollo, Daniela, Horner, Jonathan, Lewis, Geraint F, Nataf, David M, Nordlander, Thomas, Stello, Denis, Ting, Yuan-Sen, and Tinney, Chris

Subjects
STARS, MOLECULAR absorption spectra, SIGNAL-to-noise ratio, SUPERVISED learning, RADIAL velocity of stars
Abstract

Swan bands – characteristic molecular absorption features of the C2 molecule – are a spectroscopic signature of carbon-enhanced stars. They can also be used to identify carbon-enhanced metal-poor (CEMP) stars. The GALAH (GALactic Archaeology with Hermes) is a magnitude-limited survey of stars producing high-resolution, high-signal-to-noise spectra. We used 627 708 GALAH spectra to search for carbon-enhanced stars with a supervised and unsupervised classification algorithm, relying on the imprint of the Swan bands. We identified 918 carbon-enhanced stars, including 12 already described in the literature. An unbiased selection function of the GALAH survey allows us to perform a population study of carbon-enhanced stars. Most of them are giants, out of which we find 28 CEMP candidates. A large fraction of our carbon-enhanced stars with repeated observations show variation in radial velocity, hinting that there is a large fraction of variables among them. 32 of the detected stars also show strong Lithium enhancement in their spectra. [ABSTRACT FROM AUTHOR]

Published
2019
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171. The GALAH survey: co-orbiting stars and chemical tagging.

Author

Simpson, Jeffrey D, Martell, Sarah L, Da Costa, Gary, Casey, Andrew R, Freeman, Ken C, Horner, Jonathan, Ting, Yuan-Sen, Nataf, David M, Lewis, Geraint F, Ness, Melissa K, Zucker, Daniel B, Cottrell, Peter L, Čotar, Klemen, Asplund, Martin, Bland-Hawthorn, Joss, Buder, Sven, D'Orazi, Valentina, De Silva, Gayandhi M, Duong, Ly, and Kos, Janez

Subjects
STELLAR orbits, STAR formation, BINARY stars, DISKS (Astrophysics), MILKY Way
Abstract

We present a study using the second data release of the GALAH survey of stellar parameters and elemental abundances of 15 pairs of stars identified by Oh et al. They identified these pairs as potentially co-moving pairs using proper motions and parallaxes from Gaia DR1. We find that 11 very wide (>1 pc) pairs of stars do in fact have similar Galactic orbits, while a further four claimed co-moving pairs are not truly co-orbiting. Eight of the 11 co-orbiting pairs have reliable stellar parameters and abundances, and we find that three of those are quite similar in their abundance patterns, while five have significant [Fe/H] differences. For the latter, this indicates that they could be co-orbiting because of the general dynamical coldness of the thin disc, or perhaps resonances induced by the Galaxy, rather than a shared formation site. Stars such as these, wide binaries, debris of past star formation episodes, and coincidental co-orbiters, are crucial for exploring the limits of chemical tagging in the Milky Way. [ABSTRACT FROM AUTHOR]

Published
2019
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172. GRACES observations of young [α/Fe]-rich stars

Author

Yong, David, primary, Casagrande, Luca, additional, Venn, Kim A., additional, Chené, André-Nicolas, additional, Keown, Jared, additional, Malo, Lison, additional, Martioli, Eder, additional, Alves-Brito, Alan, additional, Asplund, Martin, additional, Dotter, Aaron, additional, Martell, Sarah L., additional, Meléndez, Jorge, additional, and Schlesinger, Katharine J., additional

Published
2016
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173. Studying Young Stars with Large Spectroscopic Surveys

Author

Martell, Sarah L. and Martell, Sarah L.

Abstract

Galactic archaeology is the study of the history of star formation and chemical evolution in the Milky Way, based on present-day stellar populations. Studies of young stars are a key anchor point for Galactic archaeology, since quantities like the initial mass function and the star formation rate can be studied directly in young clusters and star forming regions. Conversely, massive spectroscopic Galactic archaeology surveys can be used as a data source for young star studies., Comment: To appear in Proc. IAU Symp. 314 (Kastner, Stelzer & Metchev, eds)

Published
2015
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174. Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the APOGEE Survey

Author

Meszaros, Szabolcs, Martell, Sarah L., Shetrone, Matthew, Lucatello, Sara, Troup, Nicholas W., Bovy, Jo, Cunha, Katia, Garcia-Hernandez, Domingo A., Overbeek, Jamie C., Prieto, Carlos Allende, Beers, Timothy C., Frinchaboy, Peter M., Perez, Ana E. Garcia, Hearty, Fred R., Holtzman, Jon, Majewski, Steven R., Nidever, David L., Schiavon, Ricardo P., Schneider, Donald P., Sobeck, Jennifer S., Smith, Verne V., Zamora, Olga, Zasowski, Gail, Meszaros, Szabolcs, Martell, Sarah L., Shetrone, Matthew, Lucatello, Sara, Troup, Nicholas W., Bovy, Jo, Cunha, Katia, Garcia-Hernandez, Domingo A., Overbeek, Jamie C., Prieto, Carlos Allende, Beers, Timothy C., Frinchaboy, Peter M., Perez, Ana E. Garcia, Hearty, Fred R., Holtzman, Jon, Majewski, Steven R., Nidever, David L., Schiavon, Ricardo P., Schneider, Donald P., Sobeck, Jennifer S., Smith, Verne V., Zamora, Olga, and Zasowski, Gail

Abstract

We investigate the light-element behavior of red giant stars in Northern globular clusters (GCs) observed by the SDSS-III Apache Point Observatory Galactic Evolution Experiment (APOGEE). We derive abundances of nine elements (Fe, C, N, O, Mg, Al, Si, Ca, and Ti) for 428 red giant stars in 10 globular clusters. The intrinsic abundance range relative to measurement errors is examined, and the well-known C-N and Mg-Al anticorrelations are explored using an extreme-deconvolution code for the first time in a consistent way. We find that Mg and Al drive the population membership in most clusters, except in M107 and M71, the two most metal-rich clusters in our study, where the grouping is most sensitive to N. We also find a diversity in the abundance distributions, with some clusters exhibiting clear abundance bimodalities (for example M3 and M53) while others show extended distributions. The spread of Al abundances increases significantly as cluster average metallicity decreases as previously found by other works, which we take as evidence that low metallicity, intermediate mass AGB polluters were more common in the more metal poor clusters. The statistically significant correlation of [Al/Fe] with [Si/Fe] in M15 suggests that $^{28}$Si leakage has occurred in this cluster. We also present C, N and O abundances for stars cooler than 4500 K and examine the behavior of A(C+N+O) in each cluster as a function of temperature and [Al/Fe]. The scatter of A(C+N+O) is close to its estimated uncertainty in all clusters and independent on stellar temperature. A(C+N+O) exhibits small correlations and anticorrelations with [Al/Fe] in M3 and M13, but we cannot be certain about these relations given the size of our abundance uncertainties. Star-to-star variations of $\alpha-$elements (Si, Ca, Ti) abundances are comparable to our estimated errors in all clusters., Comment: 22 pages, 13 figures, 8 tables, accepted to AJ, fixed some typos in text

Published
2015
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175. The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III

Author

Alam, Shadab, Albareti, Franco D., Prieto, Carlos Allende, Anders, F., Anderson, Scott F., Andrews, Brett H., Armengaud, Eric, Aubourg, Éric, Bailey, Stephen, Bautista, Julian E., Beaton, Rachael L., Beers, Timothy C., Bender, Chad F., Berlind, Andreas A., Beutler, Florian, Bhardwaj, Vaishali, Bird, Jonathan C., Bizyaev, Dmitry, Blake, Cullen H., Blanton, Michael R., Blomqvist, Michael, Bochanski, John J., Bolton, Adam S., Bovy, Jo, Bradley, A. Shelden, Brandt, W. N., Brauer, D. E., Brinkmann, J., Brown, Peter J., Brownstein, Joel R., Burden, Angela, Burtin, Etienne, Busca, Nicolás G., Cai, Zheng, Capozzi, Diego, Rosell, Aurelio Carnero, Carrera, Ricardo, Chen, Yen-Chi, Chiappini, Cristina, Chojnowski, S. Drew, Chuang, Chia-Hsun, Clerc, Nicolas, Comparat, Johan, Covey, Kevin, Croft, Rupert A. C., Cuesta, Antonio J., Cunha, Katia, da Costa, Luiz N., Da Rio, Nicola, Davenport, James R. A., Dawson, Kyle S., De Lee, Nathan, Delubac, Timothée, Deshpande, Rohit, Dutra-Ferreira, Letícia, Dwelly, Tom, Ealet, Anne, Ebelke, Garrett L., Edmondson, Edward M., Eisenstein, Daniel J., Escoffier, Stephanie, Esposito, Massimiliano, Fan, Xiaohui, Fernández-Alvar, Emma, Feuillet, Diane, Ak, Nurten Filiz, Finley, Hayley, Finoguenov, Alexis, Flaherty, Kevin, Fleming, Scott W., Font-Ribera, Andreu, Foster, Jonathan, Frinchaboy, Peter M., Galbraith-Frew, J. G., García-Hernández, D. A., Pérez, Ana E. García, Gaulme, Patrick, Ge, Jian, Génova-Santos, R., Ghezzi, Luan, Gillespie, Bruce A., Girardi, Léo, Goddard, Daniel, Gontcho, Satya Gontcho A, Hernández, Jonay I. González, Grebel, Eva K., Grieb, Jan Niklas, Grieves, Nolan, Gunn, James E., Guo, Hong, Harding, Paul, Hasselquist, Sten, Hawley, Suzanne L., Hayden, Michael, Hearty, Fred R., Ho, Shirley, Hogg, David W., Holley-Bockelmann, Kelly, Holtzman, Jon A., Honscheid, Klaus, Huehnerhoff, Joseph, Jiang, Linhua, Johnson, Jennifer A., Kinemuchi, Karen, Kirkby, David, Kitaura, Francisco, Klaene, Mark A., Kneib, Jean-Paul, Koenig, Xavier P., Lam, Charles R., Lan, Ting-Wen, Lang, Dustin, Laurent, Pierre, Goff, Jean-Marc Le, Leauthaud, Alexie, Lee, Khee-Gan, Lee, Young Sun, Licquia, Timothy C., Liu, Jian, Long, Daniel C., López-Corredoira, Martín, Lorenzo-Oliveira, Diego, Lucatello, Sara, Lundgren, Britt, Lupton, Robert H., Mack III, Claude E., Mahadevan, Suvrath, Maia, Marcio A. G., Majewski, Steven R., Malanushenko, Elena, Malanushenko, Viktor, Manchado, A., Manera, Marc, Mao, Qingqing, Maraston, Claudia, Marchwinski, Robert C., Margala, Daniel, Martell, Sarah L., Martig, Marie, Masters, Karen L., McBride, Cameron K., McGehee, Peregrine M., McGreer, Ian D., McMahon, Richard G., Ménard, Brice, Menzel, Marie-Luise, Merloni, Andrea, Mészáros, Szabolcs, Miller, Adam A., Miralda-Escudé, Jordi, Miyatake, Hironao, Montero-Dorta, Antonio D., More, Surhud, Morice-Atkinson, Xan, Morrison, Heather L., Muna, Demitri, Myers, Adam D., Newman, Jeffrey A., Neyrinck, Mark, Nguyen, Duy Cuong, Nichol, Robert C., Nidever, David L., Noterdaeme, Pasquier, Nuza, Sebastián E., O'Connell, Julia E., O'Connell, Robert W., O'Connell, Ross, Ogando, Ricardo L. C., Olmstead, Matthew D., Oravetz, Audrey E., Oravetz, Daniel J., Osumi, Keisuke, Owen, Russell, Padgett, Deborah L., Padmanabhan, Nikhil, Paegert, Martin, Palanque-Delabrouille, Nathalie, Pan, Kaike, Parejko, John K., Park, Changbom, Pâris, Isabelle, Pattarakijwanich, Petchara, Pellejero-Ibanez, M., Pepper, Joshua, Percival, Will J., Pérez-Fournon, Ismael, Pérez-Ràfols, Ignasi, Petitjean, Patrick, Pieri, Matthew M., Pinsonneault, Marc H., de Mello, Gustavo F. Porto, Prada, Francisco, Prakash, Abhishek, Price-Whelan, Adrian M., Raddick, M. Jordan, Rahman, Mubdi, Reid, Beth A., Rich, James, Rix, Hans-Walter, Robin, Annie C., Rockosi, Constance M., Rodrigues, Thaíse S., Rodríguez-Rottes, Sergio, Roe, Natalie A., Ross, Ashley J., Ross, Nicholas P., Rossi, Graziano, Ruan, John J., Rubiño-Martín, J. A., Rykoff, Eli S., Salazar-Albornoz, Salvador, Salvato, Mara, Samushia, Lado, Sánchez, Ariel G., Santiago, Basílio, Sayres, Conor, Schiavon, Ricardo P., Schlegel, David J., Schmidt, Sarah J., Schneider, Donald P., Schultheis, Mathias, Schwope, Axel D., Scóccola, C. G., Sellgren, Kris, Seo, Hee-Jong, Shane, Neville, Shen, Yue, Shetrone, Matthew, Shu, Yiping, Sivarani, Thirupathi, Skrutskie, M. F., Slosar, Anže, Smith, Verne V., Sobreira, Flávia, Stassun, Keivan G., Steinmetz, Matthias, Strauss, Michael A., Streblyanska, Alina, Swanson, Molly E. C., Tan, Jonathan C., Tayar, Jamie, Terrien, Ryan C., Thakar, Aniruddha R., Thomas, Daniel, Thompson, Benjamin A., Tinker, Jeremy L., Tojeiro, Rita, Troup, Nicholas W., Vargas-Magaña, Mariana, Vazquez, Jose A., Verde, Licia, Viel, Matteo, Vogt, Nicole P., Wake, David A., Wang, Ji, Weaver, Benjamin A., Weinberg, David H., Weiner, Benjamin J., White, Martin, Wilson, John C., Wisniewski, John P., Wood-Vasey, W. M., Yèche, Christophe, York, Donald G., Zakamska, Nadia L., Zamora, O., Zasowski, Gail, Zehavi, Idit, Zhao, Gong-Bo, Zheng, Zheng, Zhou, Xu, Zhou, Zhimin, Zhu, Guangtun, Zou, Hu, Alam, Shadab, Albareti, Franco D., Prieto, Carlos Allende, Anders, F., Anderson, Scott F., Andrews, Brett H., Armengaud, Eric, Aubourg, Éric, Bailey, Stephen, Bautista, Julian E., Beaton, Rachael L., Beers, Timothy C., Bender, Chad F., Berlind, Andreas A., Beutler, Florian, Bhardwaj, Vaishali, Bird, Jonathan C., Bizyaev, Dmitry, Blake, Cullen H., Blanton, Michael R., Blomqvist, Michael, Bochanski, John J., Bolton, Adam S., Bovy, Jo, Bradley, A. Shelden, Brandt, W. N., Brauer, D. E., Brinkmann, J., Brown, Peter J., Brownstein, Joel R., Burden, Angela, Burtin, Etienne, Busca, Nicolás G., Cai, Zheng, Capozzi, Diego, Rosell, Aurelio Carnero, Carrera, Ricardo, Chen, Yen-Chi, Chiappini, Cristina, Chojnowski, S. Drew, Chuang, Chia-Hsun, Clerc, Nicolas, Comparat, Johan, Covey, Kevin, Croft, Rupert A. C., Cuesta, Antonio J., Cunha, Katia, da Costa, Luiz N., Da Rio, Nicola, Davenport, James R. A., Dawson, Kyle S., De Lee, Nathan, Delubac, Timothée, Deshpande, Rohit, Dutra-Ferreira, Letícia, Dwelly, Tom, Ealet, Anne, Ebelke, Garrett L., Edmondson, Edward M., Eisenstein, Daniel J., Escoffier, Stephanie, Esposito, Massimiliano, Fan, Xiaohui, Fernández-Alvar, Emma, Feuillet, Diane, Ak, Nurten Filiz, Finley, Hayley, Finoguenov, Alexis, Flaherty, Kevin, Fleming, Scott W., Font-Ribera, Andreu, Foster, Jonathan, Frinchaboy, Peter M., Galbraith-Frew, J. G., García-Hernández, D. A., Pérez, Ana E. García, Gaulme, Patrick, Ge, Jian, Génova-Santos, R., Ghezzi, Luan, Gillespie, Bruce A., Girardi, Léo, Goddard, Daniel, Gontcho, Satya Gontcho A, Hernández, Jonay I. González, Grebel, Eva K., Grieb, Jan Niklas, Grieves, Nolan, Gunn, James E., Guo, Hong, Harding, Paul, Hasselquist, Sten, Hawley, Suzanne L., Hayden, Michael, Hearty, Fred R., Ho, Shirley, Hogg, David W., Holley-Bockelmann, Kelly, Holtzman, Jon A., Honscheid, Klaus, Huehnerhoff, Joseph, Jiang, Linhua, Johnson, Jennifer A., Kinemuchi, Karen, Kirkby, David, Kitaura, Francisco, Klaene, Mark A., Kneib, Jean-Paul, Koenig, Xavier P., Lam, Charles R., Lan, Ting-Wen, Lang, Dustin, Laurent, Pierre, Goff, Jean-Marc Le, Leauthaud, Alexie, Lee, Khee-Gan, Lee, Young Sun, Licquia, Timothy C., Liu, Jian, Long, Daniel C., López-Corredoira, Martín, Lorenzo-Oliveira, Diego, Lucatello, Sara, Lundgren, Britt, Lupton, Robert H., Mack III, Claude E., Mahadevan, Suvrath, Maia, Marcio A. G., Majewski, Steven R., Malanushenko, Elena, Malanushenko, Viktor, Manchado, A., Manera, Marc, Mao, Qingqing, Maraston, Claudia, Marchwinski, Robert C., Margala, Daniel, Martell, Sarah L., Martig, Marie, Masters, Karen L., McBride, Cameron K., McGehee, Peregrine M., McGreer, Ian D., McMahon, Richard G., Ménard, Brice, Menzel, Marie-Luise, Merloni, Andrea, Mészáros, Szabolcs, Miller, Adam A., Miralda-Escudé, Jordi, Miyatake, Hironao, Montero-Dorta, Antonio D., More, Surhud, Morice-Atkinson, Xan, Morrison, Heather L., Muna, Demitri, Myers, Adam D., Newman, Jeffrey A., Neyrinck, Mark, Nguyen, Duy Cuong, Nichol, Robert C., Nidever, David L., Noterdaeme, Pasquier, Nuza, Sebastián E., O'Connell, Julia E., O'Connell, Robert W., O'Connell, Ross, Ogando, Ricardo L. C., Olmstead, Matthew D., Oravetz, Audrey E., Oravetz, Daniel J., Osumi, Keisuke, Owen, Russell, Padgett, Deborah L., Padmanabhan, Nikhil, Paegert, Martin, Palanque-Delabrouille, Nathalie, Pan, Kaike, Parejko, John K., Park, Changbom, Pâris, Isabelle, Pattarakijwanich, Petchara, Pellejero-Ibanez, M., Pepper, Joshua, Percival, Will J., Pérez-Fournon, Ismael, Pérez-Ràfols, Ignasi, Petitjean, Patrick, Pieri, Matthew M., Pinsonneault, Marc H., de Mello, Gustavo F. Porto, Prada, Francisco, Prakash, Abhishek, Price-Whelan, Adrian M., Raddick, M. Jordan, Rahman, Mubdi, Reid, Beth A., Rich, James, Rix, Hans-Walter, Robin, Annie C., Rockosi, Constance M., Rodrigues, Thaíse S., Rodríguez-Rottes, Sergio, Roe, Natalie A., Ross, Ashley J., Ross, Nicholas P., Rossi, Graziano, Ruan, John J., Rubiño-Martín, J. A., Rykoff, Eli S., Salazar-Albornoz, Salvador, Salvato, Mara, Samushia, Lado, Sánchez, Ariel G., Santiago, Basílio, Sayres, Conor, Schiavon, Ricardo P., Schlegel, David J., Schmidt, Sarah J., Schneider, Donald P., Schultheis, Mathias, Schwope, Axel D., Scóccola, C. G., Sellgren, Kris, Seo, Hee-Jong, Shane, Neville, Shen, Yue, Shetrone, Matthew, Shu, Yiping, Sivarani, Thirupathi, Skrutskie, M. F., Slosar, Anže, Smith, Verne V., Sobreira, Flávia, Stassun, Keivan G., Steinmetz, Matthias, Strauss, Michael A., Streblyanska, Alina, Swanson, Molly E. C., Tan, Jonathan C., Tayar, Jamie, Terrien, Ryan C., Thakar, Aniruddha R., Thomas, Daniel, Thompson, Benjamin A., Tinker, Jeremy L., Tojeiro, Rita, Troup, Nicholas W., Vargas-Magaña, Mariana, Vazquez, Jose A., Verde, Licia, Viel, Matteo, Vogt, Nicole P., Wake, David A., Wang, Ji, Weaver, Benjamin A., Weinberg, David H., Weiner, Benjamin J., White, Martin, Wilson, John C., Wisniewski, John P., Wood-Vasey, W. M., Yèche, Christophe, York, Donald G., Zakamska, Nadia L., Zamora, O., Zasowski, Gail, Zehavi, Idit, Zhao, Gong-Bo, Zheng, Zheng, Zhou, Xu, Zhou, Zhimin, Zhu, Guangtun, and Zou, Hu

Abstract

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 sq. deg of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-Object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include measured abundances of 15 different elements for each star. In total, SDSS-III added 2350 sq. deg of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 sq. deg; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5,513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra., Comment: DR12 data are available at http://www.sdss3.org/dr12. 30 pages. 11 figures. Accepted to ApJS

Published
2015
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178. THE ELEVENTH AND TWELFTH DATA RELEASES OF THE SLOAN DIGITAL SKY SURVEY: FINAL DATA FROM SDSS-III

Author

Alam, Shadab, primary, Albareti, Franco D., additional, Prieto, Carlos Allende, additional, Anders, F., additional, Anderson, Scott F., additional, Anderton, Timothy, additional, Andrews, Brett H., additional, Armengaud, Eric, additional, Aubourg, Éric, additional, Bailey, Stephen, additional, Basu, Sarbani, additional, Bautista, Julian E., additional, Beaton, Rachael L., additional, Beers, Timothy C., additional, Bender, Chad F., additional, Berlind, Andreas A., additional, Beutler, Florian, additional, Bhardwaj, Vaishali, additional, Bird, Jonathan C., additional, Bizyaev, Dmitry, additional, Blake, Cullen H., additional, Blanton, Michael R., additional, Blomqvist, Michael, additional, Bochanski, John J., additional, Bolton, Adam S., additional, Bovy, Jo, additional, Bradley, A. Shelden, additional, Brandt, W. N., additional, Brauer, D. E., additional, Brinkmann, J., additional, Brown, Peter J., additional, Brownstein, Joel R., additional, Burden, Angela, additional, Burtin, Etienne, additional, Busca, Nicolás G., additional, Cai, Zheng, additional, Capozzi, Diego, additional, Rosell, Aurelio Carnero, additional, Carr, Michael A., additional, Carrera, Ricardo, additional, Chambers, K. C., additional, Chaplin, William James, additional, Chen, Yen-Chi, additional, Chiappini, Cristina, additional, Chojnowski, S. Drew, additional, Chuang, Chia-Hsun, additional, Clerc, Nicolas, additional, Comparat, Johan, additional, Covey, Kevin, additional, Croft, Rupert A. C., additional, Cuesta, Antonio J., additional, Cunha, Katia, additional, Costa, Luiz N. da, additional, Rio, Nicola Da, additional, Davenport, James R. A., additional, Dawson, Kyle S., additional, Lee, Nathan De, additional, Delubac, Timothée, additional, Deshpande, Rohit, additional, Dhital, Saurav, additional, Dutra-Ferreira, Letícia, additional, Dwelly, Tom, additional, Ealet, Anne, additional, Ebelke, Garrett L., additional, Edmondson, Edward M., additional, Eisenstein, Daniel J., additional, Ellsworth, Tristan, additional, Elsworth, Yvonne, additional, Epstein, Courtney R., additional, Eracleous, Michael, additional, Escoffier, Stephanie, additional, Esposito, Massimiliano, additional, Evans, Michael L., additional, Fan, Xiaohui, additional, Fernández-Alvar, Emma, additional, Feuillet, Diane, additional, Ak, Nurten Filiz, additional, Finley, Hayley, additional, Finoguenov, Alexis, additional, Flaherty, Kevin, additional, Fleming, Scott W., additional, Font-Ribera, Andreu, additional, Foster, Jonathan, additional, Frinchaboy, Peter M., additional, Galbraith-Frew, J. G., additional, García, Rafael A., additional, García-Hernández, D. A., additional, Pérez, Ana E. García, additional, Gaulme, Patrick, additional, Ge, Jian, additional, Génova-Santos, R., additional, Georgakakis, A., additional, Ghezzi, Luan, additional, Gillespie, Bruce A., additional, Girardi, Léo, additional, Goddard, Daniel, additional, Gontcho, Satya Gontcho A, additional, Hernández, Jonay I. González, additional, Grebel, Eva K., additional, Green, Paul J., additional, Grieb, Jan Niklas, additional, Grieves, Nolan, additional, Gunn, James E., additional, Guo, Hong, additional, Harding, Paul, additional, Hasselquist, Sten, additional, Hawley, Suzanne L., additional, Hayden, Michael, additional, Hearty, Fred R., additional, Hekker, Saskia, additional, Ho, Shirley, additional, Hogg, David W., additional, Holley-Bockelmann, Kelly, additional, Holtzman, Jon A., additional, Honscheid, Klaus, additional, Huber, Daniel, additional, Huehnerhoff, Joseph, additional, Ivans, Inese I., additional, Jiang, Linhua, additional, Johnson, Jennifer A., additional, Kinemuchi, Karen, additional, Kirkby, David, additional, Kitaura, Francisco, additional, Klaene, Mark A., additional, Knapp, Gillian R., additional, Kneib, Jean-Paul, additional, Koenig, Xavier P., additional, Lam, Charles R., additional, Lan, Ting-Wen, additional, Lang, Dustin, additional, Laurent, Pierre, additional, Goff, Jean-Marc Le, additional, Leauthaud, Alexie, additional, Lee, Khee-Gan, additional, Lee, Young Sun, additional, Licquia, Timothy C., additional, Liu, Jian, additional, Long, Daniel C., additional, López-Corredoira, Martín, additional, Lorenzo-Oliveira, Diego, additional, Lucatello, Sara, additional, Lundgren, Britt, additional, Lupton, Robert H., additional, III, Claude E. Mack, additional, Mahadevan, Suvrath, additional, Maia, Marcio A. G., additional, Majewski, Steven R., additional, Malanushenko, Elena, additional, Malanushenko, Viktor, additional, Manchado, A., additional, Manera, Marc, additional, Mao, Qingqing, additional, Maraston, Claudia, additional, Marchwinski, Robert C., additional, Margala, Daniel, additional, Martell, Sarah L., additional, Martig, Marie, additional, Masters, Karen L., additional, Mathur, Savita, additional, McBride, Cameron K., additional, McGehee, Peregrine M., additional, McGreer, Ian D., additional, McMahon, Richard G., additional, Ménard, Brice, additional, Menzel, Marie-Luise, additional, Merloni, Andrea, additional, Mészáros, Szabolcs, additional, Miller, Adam A., additional, Miralda-Escudé, Jordi, additional, Miyatake, Hironao, additional, Montero-Dorta, Antonio D., additional, More, Surhud, additional, Morganson, Eric, additional, Morice-Atkinson, Xan, additional, Morrison, Heather L., additional, Mosser, Benôit, additional, Muna, Demitri, additional, Myers, Adam D., additional, Nandra, Kirpal, additional, Newman, Jeffrey A., additional, Neyrinck, Mark, additional, Nguyen, Duy Cuong, additional, Nichol, Robert C., additional, Nidever, David L., additional, Noterdaeme, Pasquier, additional, Nuza, Sebastián E., additional, O’Connell, Julia E., additional, O’Connell, Robert W., additional, O’Connell, Ross, additional, Ogando, Ricardo L. C., additional, Olmstead, Matthew D., additional, Oravetz, Audrey E., additional, Oravetz, Daniel J., additional, Osumi, Keisuke, additional, Owen, Russell, additional, Padgett, Deborah L., additional, Padmanabhan, Nikhil, additional, Paegert, Martin, additional, Palanque-Delabrouille, Nathalie, additional, Pan, Kaike, additional, Parejko, John K., additional, Pâris, Isabelle, additional, Park, Changbom, additional, Pattarakijwanich, Petchara, additional, Pellejero-Ibanez, M., additional, Pepper, Joshua, additional, Percival, Will J., additional, Pérez-Fournon, Ismael, additional, Pe´rez-Ra`fols, Ignasi, additional, Petitjean, Patrick, additional, Pieri, Matthew M., additional, Pinsonneault, Marc H., additional, Mello, Gustavo F. Porto de, additional, Prada, Francisco, additional, Prakash, Abhishek, additional, Price-Whelan, Adrian M., additional, Protopapas, Pavlos, additional, Raddick, M. Jordan, additional, Rahman, Mubdi, additional, Reid, Beth A., additional, Rich, James, additional, Rix, Hans-Walter, additional, Robin, Annie C., additional, Rockosi, Constance M., additional, Rodrigues, Thaíse S., additional, Rodríguez-Torres, Sergio, additional, Roe, Natalie A., additional, Ross, Ashley J., additional, Ross, Nicholas P., additional, Rossi, Graziano, additional, Ruan, John J., additional, Rubiño-Martín, J. A., additional, Rykoff, Eli S., additional, Salazar-Albornoz, Salvador, additional, Salvato, Mara, additional, Samushia, Lado, additional, Sánchez, Ariel G., additional, Santiago, Basílio, additional, Sayres, Conor, additional, Schiavon, Ricardo P., additional, Schlegel, David J., additional, Schmidt, Sarah J., additional, Schneider, Donald P., additional, Schultheis, Mathias, additional, Schwope, Axel D., additional, Scóccola, C. G., additional, Scott, Caroline, additional, Sellgren, Kris, additional, Seo, Hee-Jong, additional, Serenelli, Aldo, additional, Shane, Neville, additional, Shen, Yue, additional, Shetrone, Matthew, additional, Shu, Yiping, additional, Aguirre, V. Silva, additional, Sivarani, Thirupathi, additional, Skrutskie, M. F., additional, Slosar, Anže, additional, Smith, Verne V., additional, Sobreira, Flávia, additional, Souto, Diogo, additional, Stassun, Keivan G., additional, Steinmetz, Matthias, additional, Stello, Dennis, additional, Strauss, Michael A., additional, Streblyanska, Alina, additional, Suzuki, Nao, additional, Swanson, Molly E. C., additional, Tan, Jonathan C., additional, Tayar, Jamie, additional, Terrien, Ryan C., additional, Thakar, Aniruddha R., additional, Thomas, Daniel, additional, Thomas, Neil, additional, Thompson, Benjamin A., additional, Tinker, Jeremy L., additional, Tojeiro, Rita, additional, Troup, Nicholas W., additional, Vargas-Magaña, Mariana, additional, Vazquez, Jose A., additional, Verde, Licia, additional, Viel, Matteo, additional, Vogt, Nicole P., additional, Wake, David A., additional, Wang, Ji, additional, Weaver, Benjamin A., additional, Weinberg, David H., additional, Weiner, Benjamin J., additional, White, Martin, additional, Wilson, John C., additional, Wisniewski, John P., additional, Wood-Vasey, W. M., additional, Ye`che, Christophe, additional, York, Donald G., additional, Zakamska, Nadia L., additional, Zamora, O., additional, Zasowski, Gail, additional, Zehavi, Idit, additional, Zhao, Gong-Bo, additional, Zheng, Zheng, additional, Zhou (周旭), Xu, additional, Zhou (周志民), Zhimin, additional, Zou (邹虎), Hu, additional, and Zhu, Guangtun, additional

Published
2015
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179. EXPLORING ANTICORRELATIONS AND LIGHT ELEMENT VARIATIONS IN NORTHERN GLOBULAR CLUSTERS OBSERVED BY THE APOGEE SURVEY

Author

Mészáros, Szabolcs, primary, Martell, Sarah L., additional, Shetrone, Matthew, additional, Lucatello, Sara, additional, Troup, Nicholas W., additional, Bovy, Jo, additional, Cunha, Katia, additional, García-Hernández, Domingo A., additional, Overbeek, Jamie C., additional, Prieto, Carlos Allende, additional, Beers, Timothy C., additional, Frinchaboy, Peter M., additional, Pérez, Ana E. García, additional, Hearty, Fred R., additional, Holtzman, Jon, additional, Majewski, Steven R., additional, Nidever, David L., additional, Schiavon, Ricardo P., additional, Schneider, Donald P., additional, Sobeck, Jennifer S., additional, Smith, Verne V., additional, Zamora, Olga, additional, and Zasowski, Gail, additional

Published
2015
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180. ESO452-SC11: the lowest mass globular cluster with a potential chemical inhomogeneity.

Author

Simpson, Jeffrey D., De Silva, Gayandhi, Martell, Sarah L., Navin, Colin A., and Zucker, Daniel B.

Subjects
GLOBULAR clusters, LIGHT elements, CYANOGEN, SUPERGIANT stars, ASYMPTOTIC giant branch stars
Abstract

We present the largest spectroscopic investigation of one of the faintest and least studied stellar clusters of the MilkyWay, ESO 452-SC11. Using the Anglo-Australian Telescope AAOmega and Keck High Resolution Echelle Spectrometer spectrographs we have identified 11 members of the cluster and found indications of star-to-star light element abundance variation, primarily using the blue cyanogen absorption features. From a stellar density profile, we estimate a total cluster mass of (6.8 ± 3.4) × 103M☉. This would make ESO 452-SC11 the lowest mass cluster with evidence for multiple populations. These data were also used to measure the radial velocity of the cluster (16.7 ± 0.3 kms-1) and confirm that ESO 452-SC11 is relatively metal rich for a globular cluster ([Fe/H]=-0.81 ± 0.13). All known massive clusters studied in detail show multiple populations of stars each with a different chemical composition, but many low-mass globular clusters appear to be chemically homogeneous. ESO 452-SC11 sets a lower mass limit for the multiple stellar population phenomenon. [ABSTRACT FROM AUTHOR]

Published
2017
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182. The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment

Author

Ahn, Christopher P., Alexandroff, Rachael, Prieto, Carlos Allende, Anders, Friedrich, Anderson, Scott F., Anderton, Timothy, Andrews, Brett H., Aubourg, Éric, Bailey, Stephen, Bastien, Fabienne A., Bautista, Julian E., Beers, Timothy C., Beifiori, Alessandra, Bender, Chad F., Berlind, Andreas A., Beutler, Florian, Bhardwaj, Vaishali, Bird, Jonathan C., Bizyaev, Dmitry, Blake, Cullen H., Blanton, Michael R., Blomqvist, Michael, Bochanski, John J., Bolton, Adam S., Borde, Arnaud, Bovy, Jo, Bradley, Alaina Shelden, Brandt, W. N., Brauer, Dorothée, Brinkmann, J., Brownstein, Joel R., Busca, Nicolás G., Carithers, William, Carlberg, Joleen K., Carnero, Aurelio R., Carr, Michael A., Chiappini, Cristina, Chojnowski, S. Drew, Chuang, Chia-Hsun, Comparat, Johan, Crepp, Justin R., Cristiani, Stefano, Croft, Rupert A. C., Cuesta, Antonio J., Cunha, Katia, da Costa, Luiz N., Dawson, Kyle S., De Lee, Nathan, Dean, Janice D. R., Delubac, Timothée, Deshpande, Rohit, Dhital, Saurav, Ealet, Anne, Ebelke, Garrett L., Edmondson, Edward M., Eisenstein, Daniel J., Epstein, Courtney R., Escoffier, Stephanie, Esposito, Massimiliano, Evans, Michael L., Fabbian, D., Fan, Xiaohui, Favole, Ginevra, Castellá, Bruno Femenía, Alvar, Emma Fernández, Feuillet, Diane, Ak, Nurten Filiz, Finley, Hayley, Fleming, Scott W., Font-Ribera, Andreu, Frinchaboy, Peter M., Galbraith-Frew, J. G., García-Hernández, D. A., Pérez, Ana E. García, Ge, Jian, Génova-Santos, R., Gillespie, Bruce A., Girardi, Léo, Hernández, Jonay I. González, Gott III, J. Richard, Gunn, James E., Guo, Hong, Halverson, Samuel, Harding, Paul, Harris, David W., Hasselquist, Sten, Hawley, Suzanne L., Hayden, Michael, Hearty, Frederick R., Davó, Artemio Herrero, Ho, Shirley, Hogg, David W., Holtzman, Jon A., Honscheid, Klaus, Huehnerhoff, Joseph, Ivans, Inese I., Jackson, Kelly M., Jiang, Peng, Johnson, Jennifer A., Kirkby, David, Kinemuchi, K., Klaene, Mark A., Kneib, Jean-Paul, Koesterke, Lars, Lan, Ting-Wen, Lang, Dustin, Goff, Jean-Marc Le, Lee, Khee-Gan, Lee, Young Sun, Long, Daniel C., Loomis, Craig P., Lucatello, Sara, Lupton, Robert H., Ma, Bo, Mack III, Claude E., Mahadevan, Suvrath, Maia, Marcio A. G., Majewski, Steven R., Malanushenko, Elena, Malanushenko, Viktor, Manchado, A., Manera, Marc, Maraston, Claudia, Margala, Daniel, Martell, Sarah L., Masters, Karen L., McBride, Cameron K., McGreer, Ian D., McMahon, Richard G., Ménard, Brice, Mészáros, Sz., Miralda-Escudé, Jordi, Miyatake, Hironao, Montero-Dorta, Antonio D., Montesano, Francesco, More, Surhud, Morrison, Heather L., Muna, Demitri, Munn, Jeffrey A., Myers, Adam D., Nguyen, Duy Cuong, Nichol, Robert C., Nidever, David L., Noterdaeme, Pasquier, Nuza, Sebastián E., O'Connell, Julia E., O'Connell, Robert W., O'Connell, Ross, Olmstead, Matthew D., Oravetz, Daniel J., Owen, Russell, Padmanabhan, Nikhil, Palanque-Delabrouille, Nathalie, Pan, Kaike, Parejko, John K., Pâris, Isabelle, Pepper, Joshua, Percival, Will J., Pérez-Ràfols, Ignasi, Perottoni, Hélio Dotto, Petitjean, Patrick, Pieri, Matthew M., Pinsonneault, M. H., Prada, Francisco, Price-Whelan, Adrian M., Raddick, M. Jordan, Rahman, Mubdi, Rebolo, Rafael, Reid, Beth A., Richards, Jonathan C., Riffel, Rogério, Robin, Annie C., Rocha-Pinto, H. J., Rockosi, Constance M., Roe, Natalie A., Ross, Ashley J., Ross, Nicholas P., Rossi, Graziano, Roy, Arpita, Rubiño-Martin, J. A., Sabiu, Cristiano G., Sánchez, Ariel G., Santiago, Basílio, Sayres, Conor, Schiavon, Ricardo P., Schlegel, David J., Schlesinger, Katharine J., Schmidt, Sarah J., Schneider, Donald P., Schultheis, Mathias, Sellgren, Kris, Seo, Hee-Jong, Shen, Yue, Shetrone, Matthew, Shu, Yiping, Simmons, Audrey E., Skrutskie, M. F., Slosar, Anže, Smith, Verne V., Snedden, Stephanie A., Sobeck, Jennifer S., Sobreira, Flavia, Stassun, Keivan G., Steinmetz, Matthias, Strauss, Michael A., Streblyanska, Alina, Suzuki, Nao, Swanson, Molly E. C., Terrien, Ryan C., Thakar, Aniruddha R., Thomas, Daniel, Thompson, Benjamin A., Tinker, Jeremy L., Tojeiro, Rita, Troup, Nicholas W., Vandenberg, Jan, Magaña, Mariana Vargas, Viel, Matteo, Vogt, Nicole P., Wake, David A., Weaver, Benjamin A., Weinberg, David H., Weiner, Benjamin J., White, Martin, White, Simon D. M., Wilson, John C., Wisniewski, John P., Wood-Vasey, W. M., Yèche, Christophe, York, Donald G., Zamora, O., Zasowski, Gail, Zehavi, Idit, Zheng, Zheng, Zhu, Guangtun, Ahn, Christopher P., Alexandroff, Rachael, Prieto, Carlos Allende, Anders, Friedrich, Anderson, Scott F., Anderton, Timothy, Andrews, Brett H., Aubourg, Éric, Bailey, Stephen, Bastien, Fabienne A., Bautista, Julian E., Beers, Timothy C., Beifiori, Alessandra, Bender, Chad F., Berlind, Andreas A., Beutler, Florian, Bhardwaj, Vaishali, Bird, Jonathan C., Bizyaev, Dmitry, Blake, Cullen H., Blanton, Michael R., Blomqvist, Michael, Bochanski, John J., Bolton, Adam S., Borde, Arnaud, Bovy, Jo, Bradley, Alaina Shelden, Brandt, W. N., Brauer, Dorothée, Brinkmann, J., Brownstein, Joel R., Busca, Nicolás G., Carithers, William, Carlberg, Joleen K., Carnero, Aurelio R., Carr, Michael A., Chiappini, Cristina, Chojnowski, S. Drew, Chuang, Chia-Hsun, Comparat, Johan, Crepp, Justin R., Cristiani, Stefano, Croft, Rupert A. C., Cuesta, Antonio J., Cunha, Katia, da Costa, Luiz N., Dawson, Kyle S., De Lee, Nathan, Dean, Janice D. R., Delubac, Timothée, Deshpande, Rohit, Dhital, Saurav, Ealet, Anne, Ebelke, Garrett L., Edmondson, Edward M., Eisenstein, Daniel J., Epstein, Courtney R., Escoffier, Stephanie, Esposito, Massimiliano, Evans, Michael L., Fabbian, D., Fan, Xiaohui, Favole, Ginevra, Castellá, Bruno Femenía, Alvar, Emma Fernández, Feuillet, Diane, Ak, Nurten Filiz, Finley, Hayley, Fleming, Scott W., Font-Ribera, Andreu, Frinchaboy, Peter M., Galbraith-Frew, J. G., García-Hernández, D. A., Pérez, Ana E. García, Ge, Jian, Génova-Santos, R., Gillespie, Bruce A., Girardi, Léo, Hernández, Jonay I. González, Gott III, J. Richard, Gunn, James E., Guo, Hong, Halverson, Samuel, Harding, Paul, Harris, David W., Hasselquist, Sten, Hawley, Suzanne L., Hayden, Michael, Hearty, Frederick R., Davó, Artemio Herrero, Ho, Shirley, Hogg, David W., Holtzman, Jon A., Honscheid, Klaus, Huehnerhoff, Joseph, Ivans, Inese I., Jackson, Kelly M., Jiang, Peng, Johnson, Jennifer A., Kirkby, David, Kinemuchi, K., Klaene, Mark A., Kneib, Jean-Paul, Koesterke, Lars, Lan, Ting-Wen, Lang, Dustin, Goff, Jean-Marc Le, Lee, Khee-Gan, Lee, Young Sun, Long, Daniel C., Loomis, Craig P., Lucatello, Sara, Lupton, Robert H., Ma, Bo, Mack III, Claude E., Mahadevan, Suvrath, Maia, Marcio A. G., Majewski, Steven R., Malanushenko, Elena, Malanushenko, Viktor, Manchado, A., Manera, Marc, Maraston, Claudia, Margala, Daniel, Martell, Sarah L., Masters, Karen L., McBride, Cameron K., McGreer, Ian D., McMahon, Richard G., Ménard, Brice, Mészáros, Sz., Miralda-Escudé, Jordi, Miyatake, Hironao, Montero-Dorta, Antonio D., Montesano, Francesco, More, Surhud, Morrison, Heather L., Muna, Demitri, Munn, Jeffrey A., Myers, Adam D., Nguyen, Duy Cuong, Nichol, Robert C., Nidever, David L., Noterdaeme, Pasquier, Nuza, Sebastián E., O'Connell, Julia E., O'Connell, Robert W., O'Connell, Ross, Olmstead, Matthew D., Oravetz, Daniel J., Owen, Russell, Padmanabhan, Nikhil, Palanque-Delabrouille, Nathalie, Pan, Kaike, Parejko, John K., Pâris, Isabelle, Pepper, Joshua, Percival, Will J., Pérez-Ràfols, Ignasi, Perottoni, Hélio Dotto, Petitjean, Patrick, Pieri, Matthew M., Pinsonneault, M. H., Prada, Francisco, Price-Whelan, Adrian M., Raddick, M. Jordan, Rahman, Mubdi, Rebolo, Rafael, Reid, Beth A., Richards, Jonathan C., Riffel, Rogério, Robin, Annie C., Rocha-Pinto, H. J., Rockosi, Constance M., Roe, Natalie A., Ross, Ashley J., Ross, Nicholas P., Rossi, Graziano, Roy, Arpita, Rubiño-Martin, J. A., Sabiu, Cristiano G., Sánchez, Ariel G., Santiago, Basílio, Sayres, Conor, Schiavon, Ricardo P., Schlegel, David J., Schlesinger, Katharine J., Schmidt, Sarah J., Schneider, Donald P., Schultheis, Mathias, Sellgren, Kris, Seo, Hee-Jong, Shen, Yue, Shetrone, Matthew, Shu, Yiping, Simmons, Audrey E., Skrutskie, M. F., Slosar, Anže, Smith, Verne V., Snedden, Stephanie A., Sobeck, Jennifer S., Sobreira, Flavia, Stassun, Keivan G., Steinmetz, Matthias, Strauss, Michael A., Streblyanska, Alina, Suzuki, Nao, Swanson, Molly E. C., Terrien, Ryan C., Thakar, Aniruddha R., Thomas, Daniel, Thompson, Benjamin A., Tinker, Jeremy L., Tojeiro, Rita, Troup, Nicholas W., Vandenberg, Jan, Magaña, Mariana Vargas, Viel, Matteo, Vogt, Nicole P., Wake, David A., Weaver, Benjamin A., Weinberg, David H., Weiner, Benjamin J., White, Martin, White, Simon D. M., Wilson, John C., Wisniewski, John P., Wood-Vasey, W. M., Yèche, Christophe, York, Donald G., Zamora, O., Zasowski, Gail, Zehavi, Idit, Zheng, Zheng, and Zhu, Guangtun

Abstract

The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the tenth public data release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R~22,500 300-fiber spectrograph covering 1.514--1.696 microns. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included.DR10 also roughly doubles the number of BOSS spectra over those included in the ninth data release. DR10 includes a total of 1,507,954 BOSS spectra, comprising 927,844 galaxy spectra; 182,009 quasar spectra; and 159,327 stellar spectra, selected over 6373.2 square degrees., Comment: 15 figures; 1 table. Accepted to ApJS. DR10 is available at http://www.sdss3.org/dr10 v3 fixed 3 diacritic markings in the arXiv HTML listing of the author names

Published
2013
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183. Chemical evolution in star clusters: the role of mass and environment

Author

Martell, Sarah L., Duffau, Sonia, Milone, Antonino P., Smith, Graeme H., Briley, Michael M., Grebel, Eva K., Martell, Sarah L., Duffau, Sonia, Milone, Antonino P., Smith, Graeme H., Briley, Michael M., and Grebel, Eva K.

Abstract

The process of chemical self-enrichment in stellar systems can be affected by the total mass of the system and the conditions of the large-scale environment. Globular clusters are a special dark matter-free case of chemical evolution, in which the only self-enrichment comes from material processed in stars, and only two bursts of star formation occur. We describe how observations of intermediate-age star clusters in the Large Magellanic Cloud can provide insight on the ways that mass and environment can affect the process of chemical enrichment in star clusters., Comment: 5 pages, proceedings of the meeting "Reading the book of globular clusters with the lens of stellar evolution", Rome, Nov. 26-28, 2012, to be published in Memorie della Societa' Astronomica Italiana

Published
2013

185. THE TENTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY: FIRST SPECTROSCOPIC DATA FROM THE SDSS-III APACHE POINT OBSERVATORY GALACTIC EVOLUTION EXPERIMENT

Author

Ahn, Christopher P., primary, Alexandroff, Rachael, additional, Allende Prieto, Carlos, additional, Anders, Friedrich, additional, Anderson, Scott F., additional, Anderton, Timothy, additional, Andrews, Brett H., additional, Aubourg, Éric, additional, Bailey, Stephen, additional, Bastien, Fabienne A., additional, Bautista, Julian E., additional, Beers, Timothy C., additional, Beifiori, Alessandra, additional, Bender, Chad F., additional, Berlind, Andreas A., additional, Beutler, Florian, additional, Bhardwaj, Vaishali, additional, Bird, Jonathan C., additional, Bizyaev, Dmitry, additional, Blake, Cullen H., additional, Blanton, Michael R., additional, Blomqvist, Michael, additional, Bochanski, John J., additional, Bolton, Adam S., additional, Borde, Arnaud, additional, Bovy, Jo, additional, Bradley, Alaina Shelden, additional, Brandt, W. N., additional, Brauer, Dorothée, additional, Brinkmann, J., additional, Brownstein, Joel R., additional, Busca, Nicolás G., additional, Carithers, William, additional, Carlberg, Joleen K., additional, Carnero, Aurelio R., additional, Carr, Michael A., additional, Chiappini, Cristina, additional, Chojnowski, S. Drew, additional, Chuang, Chia-Hsun, additional, Comparat, Johan, additional, Crepp, Justin R., additional, Cristiani, Stefano, additional, Croft, Rupert A. C., additional, Cuesta, Antonio J., additional, Cunha, Katia, additional, da Costa, Luiz N., additional, Dawson, Kyle S., additional, De Lee, Nathan, additional, Dean, Janice D. R., additional, Delubac, Timothée, additional, Deshpande, Rohit, additional, Dhital, Saurav, additional, Ealet, Anne, additional, Ebelke, Garrett L., additional, Edmondson, Edward M., additional, Eisenstein, Daniel J., additional, Epstein, Courtney R., additional, Escoffier, Stephanie, additional, Esposito, Massimiliano, additional, Evans, Michael L., additional, Fabbian, D., additional, Fan, Xiaohui, additional, Favole, Ginevra, additional, Femenía Castellá, Bruno, additional, Fernández Alvar, Emma, additional, Feuillet, Diane, additional, Filiz Ak, Nurten, additional, Finley, Hayley, additional, Fleming, Scott W., additional, Font-Ribera, Andreu, additional, Frinchaboy, Peter M., additional, Galbraith-Frew, J. G., additional, García-Hernández, D. A., additional, García Pérez, Ana E., additional, Ge, Jian, additional, Génova-Santos, R., additional, Gillespie, Bruce A., additional, Girardi, Léo, additional, González Hernández, Jonay I., additional, Gott, J. Richard, additional, Gunn, James E., additional, Guo, Hong, additional, Halverson, Samuel, additional, Harding, Paul, additional, Harris, David W., additional, Hasselquist, Sten, additional, Hawley, Suzanne L., additional, Hayden, Michael, additional, Hearty, Frederick R., additional, Herrero Davó, Artemio, additional, Ho, Shirley, additional, Hogg, David W., additional, Holtzman, Jon A., additional, Honscheid, Klaus, additional, Huehnerhoff, Joseph, additional, Ivans, Inese I., additional, Jackson, Kelly M., additional, Jiang, Peng, additional, Johnson, Jennifer A., additional, Kinemuchi, K., additional, Kirkby, David, additional, Klaene, Mark A., additional, Kneib, Jean-Paul, additional, Koesterke, Lars, additional, Lan, Ting-Wen, additional, Lang, Dustin, additional, Le Goff, Jean-Marc, additional, Leauthaud, Alexie, additional, Lee, Khee-Gan, additional, Lee, Young Sun, additional, Long, Daniel C., additional, Loomis, Craig P., additional, Lucatello, Sara, additional, Lupton, Robert H., additional, Ma, Bo, additional, Mack, Claude E., additional, Mahadevan, Suvrath, additional, Maia, Marcio A. G., additional, Majewski, Steven R., additional, Malanushenko, Elena, additional, Malanushenko, Viktor, additional, Manchado, A., additional, Manera, Marc, additional, Maraston, Claudia, additional, Margala, Daniel, additional, Martell, Sarah L., additional, Masters, Karen L., additional, McBride, Cameron K., additional, McGreer, Ian D., additional, McMahon, Richard G., additional, Ménard, Brice, additional, Mészáros, Sz., additional, Miralda-Escudé, Jordi, additional, Miyatake, Hironao, additional, Montero-Dorta, Antonio D., additional, Montesano, Francesco, additional, More, Surhud, additional, Morrison, Heather L., additional, Muna, Demitri, additional, Munn, Jeffrey A., additional, Myers, Adam D., additional, Nguyen, Duy Cuong, additional, Nichol, Robert C., additional, Nidever, David L., additional, Noterdaeme, Pasquier, additional, Nuza, Sebastián E., additional, O'Connell, Julia E., additional, O'Connell, Robert W., additional, O'Connell, Ross, additional, Olmstead, Matthew D., additional, Oravetz, Daniel J., additional, Owen, Russell, additional, Padmanabhan, Nikhil, additional, Palanque-Delabrouille, Nathalie, additional, Pan, Kaike, additional, Parejko, John K., additional, Parihar, Prachi, additional, Pâris, Isabelle, additional, Pepper, Joshua, additional, Percival, Will J., additional, Pérez-Ràfols, Ignasi, additional, Dotto Perottoni, Hélio, additional, Petitjean, Patrick, additional, Pieri, Matthew M., additional, Pinsonneault, M. H., additional, Prada, Francisco, additional, Price-Whelan, Adrian M., additional, Raddick, M. Jordan, additional, Rahman, Mubdi, additional, Rebolo, Rafael, additional, Reid, Beth A., additional, Richards, Jonathan C., additional, Riffel, Rogério, additional, Robin, Annie C., additional, Rocha-Pinto, H. J., additional, Rockosi, Constance M., additional, Roe, Natalie A., additional, Ross, Ashley J., additional, Ross, Nicholas P., additional, Rossi, Graziano, additional, Roy, Arpita, additional, Rubiño-Martin, J. A., additional, Sabiu, Cristiano G., additional, Sánchez, Ariel G., additional, Santiago, Basílio, additional, Sayres, Conor, additional, Schiavon, Ricardo P., additional, Schlegel, David J., additional, Schlesinger, Katharine J., additional, Schmidt, Sarah J., additional, Schneider, Donald P., additional, Schultheis, Mathias, additional, Sellgren, Kris, additional, Seo, Hee-Jong, additional, Shen, Yue, additional, Shetrone, Matthew, additional, Shu, Yiping, additional, Simmons, Audrey E., additional, Skrutskie, M. F., additional, Slosar, Anže, additional, Smith, Verne V., additional, Snedden, Stephanie A., additional, Sobeck, Jennifer S., additional, Sobreira, Flavia, additional, Stassun, Keivan G., additional, Steinmetz, Matthias, additional, Strauss, Michael A., additional, Streblyanska, Alina, additional, Suzuki, Nao, additional, Swanson, Molly E. C., additional, Terrien, Ryan C., additional, Thakar, Aniruddha R., additional, Thomas, Daniel, additional, Thompson, Benjamin A., additional, Tinker, Jeremy L., additional, Tojeiro, Rita, additional, Troup, Nicholas W., additional, Vandenberg, Jan, additional, Vargas Magaña, Mariana, additional, Viel, Matteo, additional, Vogt, Nicole P., additional, Wake, David A., additional, Weaver, Benjamin A., additional, Weinberg, David H., additional, Weiner, Benjamin J., additional, White, Martin, additional, White, Simon D. M., additional, Wilson, John C., additional, Wisniewski, John P., additional, Wood-Vasey, W. M., additional, Yèche, Christophe, additional, York, Donald G., additional, Zamora, O., additional, Zasowski, Gail, additional, Zehavi, Idit, additional, Zhao, Gong-Bo, additional, Zheng, Zheng, additional, and Zhu, Guangtun, additional

Published
2014
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187. A broad perspective on multiple abundance populations in the globular cluster NGC 1851.

Author

Simpson, Jeffrey D., Martell, Sarah L., and Navin, Colin A.

Subjects
*GLOBULAR clusters, *COSMIC abundances, *STELLAR populations, *GIANT stars, *STELLAR spectra
Abstract

We present an analysis of the multiple stellar populations of the globular cluster NGC 1851. We used lower resolution spectra of giant stars to measure CN, CH, and calcium H & K spectral indices, and determine elemental abundances for carbon and nitrogen. The CN and CH indices were used to confirm that there are four populations of stars in the cluster. The primordial population of stars, with the lowest CN, was found to be generally chemically distinct in elemental abundances from the second-generation populations. As expected, [N/Fe] increases with increasing CN strength, but the only other element that correlated with CN was barium. The two largest populations of stars were found to have the same rate of carbon astration as the stars that ascend the giant branch. We were also able to confirm that four previously identified extratidal stars are chemically associated with the cluster. This work shows the benefit of considering the chemistry of globular clusters with both high- and low-resolution spectra. [ABSTRACT FROM AUTHOR]

Published
2017
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188. Chemical tagging with APOGEE: discovery of a large population of N-rich stars in the inner Galaxy.

Author

Schiavon, Ricardo P., Zamora, Olga, Carrera, Ricardo, Lucatello, Sara, Robin, A. C., Ness, Melissa, Martell, Sarah L., Smith, Verne V., Garc÷a-Hernández, D. A., Manchado, Arturo, Schönrich, Ralph, Bastian, Nate, Chiappini, Cristina, Shetrone, Matthew, Mackereth, J. Ted, Williams, Rob A., Méeszáros, Szabolcs, Prieto, Carlos Allende, Anders, Friedrich, and Bizyaev, Dmitry

Subjects
STELLAR populations, GLOBULAR clusters, GALACTIC bulges, STAR formation, ASTRONOMICAL observations
Abstract

Formation of globular clusters (GCs), the Galactic bulge, or galaxy bulges in general is an important unsolved problem in Galactic astronomy. Homogeneous infrared observations of large samples of stars belonging to GCs and the Galactic bulge field are one of the best ways to study these problems. We report the discovery by APOGEE (Apache Point Observatory Galactic Evolution Experiment) of a population of field stars in the inner Galaxy with abundances of N, C, and Al that are typically found in GC stars. The newly discovered stars have high [N/Fe], which is correlated with [Al/Fe] and anticorrelated with [C/Fe]. They are homogeneously distributed across, and kinematically indistinguishable from, other field stars within the same volume. Their metallicity distribution is seemingly unimodal, peaking at [Fe/H] ~ - 1, thus being in disagreement with that of the Galactic GC system. Our results can be understood in terms of different scenarios. N-rich stars could be former members of dissolved GCs, in which case the mass in destroyed GCs exceeds that of the surviving GC system by a factor of ~8. In that scenario, the total mass contained in so-called 'first-generation' stars cannot be larger than that in 'second-generation' stars by more than a factor of ~9 and was certainly smaller. Conversely, our results may imply the absence of a mandatory genetic link between 'second-generation' stars and GCs. Last, but not least, N-rich stars could be the oldest stars in the Galaxy, the by-products of chemical enrichment by the first stellar generations formed in the heart of the Galaxy. [ABSTRACT FROM AUTHOR]

Published
2017
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189. The GALAH survey: the data reduction pipeline.

Author

Kos, Janez, Jane Lin, Zwitter, Tomaž, Žerjal, Maruška, Sharma, Sanjib, Bland-Hawthorn, Joss, Asplund, Martin, Casey, Andrew R., De Silva, Gayandhi M., Freeman, Ken C., Martell, Sarah L., Simpson, Jeffrey D., Schlesinger, Katharine J., Zucker, Daniel, Anguiano, Borja, Bacigalupo, Carlos, Bedding, Timothy R., Betters, Christopher, Da Costa, Gary, and Ly Duong

Subjects
PIPELINES, DATA reduction, ARCHAEOLOGY, SPECTROGRAPHS, COMPUTER software, SPECTRUM analysis
Abstract

We present the data reduction procedures being used by the GALactic Archeology with Hermes (GALAH) survey, carried out with the HERMES fibre-fed, multi-object spectrograph on the 3.9-m Anglo-Australian Telescope. GALAH is a unique survey, targeting 1 million stars brighter than magnitude V = 14 at a resolution of 28 000 with a goal to measure the abundances of 29 elements. Such a large number of high-resolution spectra necessitate the development of a reduction pipeline optimized for speed, accuracy, and consistency. We outline the design and structure of the IRAF-based reduction pipeline that we developed, specifically for GALAH, to produce fully calibrated spectra aimed for subsequent stellar atmospheric parameter estimation. The pipeline takes advantage of existing IRAF routines and other readily available software so as to be simple to maintain, testable, and reliable. A radial velocity and stellar atmospheric parameter estimator code is also presented, which is used for further data analysis and yields a useful verification of the reduction quality. We have used this estimator to quantify the data quality of GALAH for fibre cross-talk level (≲0.5 per cent) and scattered light (~5 counts in a typical 20 min exposure), resolution across the field, sky spectrum properties, wavelength solution reliability (better than 1 kms-1 accuracy), and radial velocity precision. [ABSTRACT FROM AUTHOR]

Published
2017
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190. THE NINTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY: FIRST SPECTROSCOPIC DATA FROM THE SDSS-III BARYON OSCILLATION SPECTROSCOPIC SURVEY

Author

Ahn, Christopher P., primary, Alexandroff, Rachael, additional, Allende Prieto, Carlos, additional, Anderson, Scott F., additional, Anderton, Timothy, additional, Andrews, Brett H., additional, Aubourg, Éric, additional, Bailey, Stephen, additional, Balbinot, Eduardo, additional, Barnes, Rory, additional, Bautista, Julian, additional, Beers, Timothy C., additional, Beifiori, Alessandra, additional, Berlind, Andreas A., additional, Bhardwaj, Vaishali, additional, Bizyaev, Dmitry, additional, Blake, Cullen H., additional, Blanton, Michael R., additional, Blomqvist, Michael, additional, Bochanski, John J., additional, Bolton, Adam S., additional, Borde, Arnaud, additional, Bovy, Jo, additional, Brandt, W. N., additional, Brinkmann, J., additional, Brown, Peter J., additional, Brownstein, Joel R., additional, Bundy, Kevin, additional, Busca, N. G., additional, Carithers, William, additional, Carnero, Aurelio R., additional, Carr, Michael A., additional, Casetti-Dinescu, Dana I., additional, Chen, Yanmei, additional, Chiappini, Cristina, additional, Comparat, Johan, additional, Connolly, Natalia, additional, Crepp, Justin R., additional, Cristiani, Stefano, additional, Croft, Rupert A. C., additional, Cuesta, Antonio J., additional, da Costa, Luiz N., additional, Davenport, James R. A., additional, Dawson, Kyle S., additional, de Putter, Roland, additional, De Lee, Nathan, additional, Delubac, Timothée, additional, Dhital, Saurav, additional, Ealet, Anne, additional, Ebelke, Garrett L., additional, Edmondson, Edward M., additional, Eisenstein, Daniel J., additional, Escoffier, S., additional, Esposito, Massimiliano, additional, Evans, Michael L., additional, Fan, Xiaohui, additional, Femenía Castellá, Bruno, additional, Fernández Alvar, Emma, additional, Ferreira, Leticia D., additional, Filiz Ak, N., additional, Finley, Hayley, additional, Fleming, Scott W., additional, Font-Ribera, Andreu, additional, Frinchaboy, Peter M., additional, García-Hernández, D. A., additional, Pérez, A. E. García, additional, Ge, Jian, additional, Génova-Santos, R., additional, Gillespie, Bruce A., additional, Girardi, Léo, additional, González Hernández, Jonay I., additional, Grebel, Eva K., additional, Gunn, James E., additional, Guo, Hong, additional, Haggard, Daryl, additional, Hamilton, Jean-Christophe, additional, Harris, David W., additional, Hawley, Suzanne L., additional, Hearty, Frederick R., additional, Ho, Shirley, additional, Hogg, David W., additional, Holtzman, Jon A., additional, Honscheid, Klaus, additional, Huehnerhoff, J., additional, Ivans, Inese I., additional, Ivezić, Željko, additional, Jacobson, Heather R., additional, Jiang, Linhua, additional, Johansson, Jonas, additional, Johnson, Jennifer A., additional, Kauffmann, Guinevere, additional, Kirkby, David, additional, Kirkpatrick, Jessica A., additional, Klaene, Mark A., additional, Knapp, Gillian R., additional, Kneib, Jean-Paul, additional, Le Goff, Jean-Marc, additional, Leauthaud, Alexie, additional, Lee, Khee-Gan, additional, Lee, Young Sun, additional, Long, Daniel C., additional, Loomis, Craig P., additional, Lucatello, Sara, additional, Lundgren, Britt, additional, Lupton, Robert H., additional, Ma, Bo, additional, Ma, Zhibo, additional, MacDonald, Nicholas, additional, Mack, Claude E., additional, Mahadevan, Suvrath, additional, Maia, Marcio A. G., additional, Majewski, Steven R., additional, Makler, Martin, additional, Malanushenko, Elena, additional, Malanushenko, Viktor, additional, Manchado, A., additional, Mandelbaum, Rachel, additional, Manera, Marc, additional, Maraston, Claudia, additional, Margala, Daniel, additional, Martell, Sarah L., additional, McBride, Cameron K., additional, McGreer, Ian D., additional, McMahon, Richard G., additional, Ménard, Brice, additional, Meszaros, Sz., additional, Miralda-Escudé, Jordi, additional, Montero-Dorta, Antonio D., additional, Montesano, Francesco, additional, Morrison, Heather L., additional, Muna, Demitri, additional, Munn, Jeffrey A., additional, Murayama, Hitoshi, additional, Myers, Adam D., additional, Neto, A. F., additional, Nguyen, Duy Cuong, additional, Nichol, Robert C., additional, Nidever, David L., additional, Noterdaeme, Pasquier, additional, Nuza, Sebastián E., additional, Ogando, Ricardo L. C., additional, Olmstead, Matthew D., additional, Oravetz, Daniel J., additional, Owen, Russell, additional, Padmanabhan, Nikhil, additional, Palanque-Delabrouille, Nathalie, additional, Pan, Kaike, additional, Parejko, John K., additional, Parihar, Prachi, additional, Pâris, Isabelle, additional, Pattarakijwanich, Petchara, additional, Pepper, Joshua, additional, Percival, Will J., additional, Pérez-Fournon, Ismael, additional, Pérez-Ràfols, Ignasi, additional, Petitjean, Patrick, additional, Pforr, Janine, additional, Pieri, Matthew M., additional, Pinsonneault, Marc H., additional, Porto de Mello, G. F., additional, Prada, Francisco, additional, Price-Whelan, Adrian M., additional, Raddick, M. Jordan, additional, Rebolo, Rafael, additional, Rich, James, additional, Richards, Gordon T., additional, Robin, Annie C., additional, Rocha-Pinto, Helio J., additional, Rockosi, Constance M., additional, Roe, Natalie A., additional, Ross, Ashley J., additional, Ross, Nicholas P., additional, Rossi, Graziano, additional, Rubiño-Martin, J. A., additional, Samushia, Lado, additional, Sanchez Almeida, J., additional, Sánchez, Ariel G., additional, Santiago, Basílio, additional, Sayres, Conor, additional, Schlegel, David J., additional, Schlesinger, Katharine J., additional, Schmidt, Sarah J., additional, Schneider, Donald P., additional, Schultheis, Mathias, additional, Schwope, Axel D., additional, Scóccola, C. G., additional, Seljak, Uros, additional, Sheldon, Erin, additional, Shen, Yue, additional, Shu, Yiping, additional, Simmerer, Jennifer, additional, Simmons, Audrey E., additional, Skibba, Ramin A., additional, Skrutskie, M. F., additional, Slosar, A., additional, Sobreira, Flavia, additional, Sobeck, Jennifer S., additional, Stassun, Keivan G., additional, Steele, Oliver, additional, Steinmetz, Matthias, additional, Strauss, Michael A., additional, Streblyanska, Alina, additional, Suzuki, Nao, additional, Swanson, Molly E. C., additional, Tal, Tomer, additional, Thakar, Aniruddha R., additional, Thomas, Daniel, additional, Thompson, Benjamin A., additional, Tinker, Jeremy L., additional, Tojeiro, Rita, additional, Tremonti, Christy A., additional, Vargas Magaña, M., additional, Verde, Licia, additional, Viel, Matteo, additional, Vikas, Shailendra K., additional, Vogt, Nicole P., additional, Wake, David A., additional, Wang, Ji, additional, Weaver, Benjamin A., additional, Weinberg, David H., additional, Weiner, Benjamin J., additional, West, Andrew A., additional, White, Martin, additional, Wilson, John C., additional, Wisniewski, John P., additional, Wood-Vasey, W. M., additional, Yanny, Brian, additional, Yèche, Christophe, additional, York, Donald G., additional, Zamora, O., additional, Zasowski, Gail, additional, Zehavi, Idit, additional, Zhao, Gong-Bo, additional, Zheng, Zheng, additional, Zhu, Guangtun, additional, and Zinn, Joel C., additional

Published
2012
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199. CARBON-ENHANCED METAL-POOR STARS: CEMP-s and CEMP-no SUBCLASSES IN THE HALO SYSTEM OF THE MILKY WAY.

Author

Carollo, Daniela, Freeman, Ken, Beers, Timothy C., Placco, Vinicius M., Tumlinson, Jason, and Martell, Sarah L.

Subjects
METAL-poor stars, CARBON, GALACTIC halos, COSMIC abundances, MILKY Way
Abstract

We explore the kinematics and orbital properties of a sample of 323 very metal-poor stars in the halo system of the Milky Way, selected from the high-resolution spectroscopic follow-up studies of Aoki et al. and Yong et al. The combined sample contains a significant fraction of carbon-enhanced metal-poor (CEMP) stars (22% or 29%, depending on whether a strict or relaxed criterion is applied for this definition). Barium abundances (or upper limits) are available for the great majority of the CEMP stars, allowing for their separation into the CEMP-s and CEMP-no subclasses. A new method to assign membership to the inner- and outer-halo populations of the Milky Way is developed, making use of the integrals of motion, and applied to determine the relative fractions of CEMP stars in these two subclasses for each halo component. Although limited by small-number statistics, the data suggest that the inner halo of the Milky Way exhibits a somewhat higher relative number of CEMP-s stars than CEMP-no stars (57% versus 43%), while the outer halo possesses a clearly higher fraction of CEMP-no stars than CEMP-s stars (70% versus 30%). Although larger samples of CEMP stars with known Ba abundances are required, this result suggests that the dominant progenitors of CEMP stars in the two halo components were different; massive stars for the outer halo, and intermediate-mass stars in the case of the inner halo. [ABSTRACT FROM AUTHOR]

Published
2014
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200. The GALAH survey: a new constraint on cosmological lithium and Galactic lithium evolution from warm dwarf stars.

Author

Gao, Xudong, Lind, Karin, Amarsi, Anish M, Buder, Sven, Bland-Hawthorn, Joss, Campbell, Simon W, Asplund, Martin, Casey, Andrew R, De Silva, Gayandhi M, Freeman, Ken C, Hayden, Michael R, Lewis, Geraint F, Martell, Sarah L, Simpson, Jeffrey D, Sharma, Sanjib, Zucker, Daniel B, Zwitter, Tomaž, Horner, Jonathan, Munari, Ulisse, and Nordlander, Thomas

Subjects
*GALACTIC evolution, *STAR clusters, *STELLAR evolution, *COOL stars (Astronomy)
Abstract

Lithium depletion and enrichment in the cosmos is not yet well understood. To help tighten constraints on stellar and Galactic evolution models, we present the largest high-resolution analysis of Li abundances A (Li) to date, with results for over |$100\, 000$| GALAH (Galactic Archeology with HERMES) field stars spanning effective temperatures |$5900\, \mathrm{K} \lesssim T_{\mathrm{eff}}\lesssim 7000\, \mathrm{K}$| and metallicities −3 ≲ [Fe/H] ≲ +0.5. We separated these stars into two groups, on the warm and cool sides of the so-called Li dip, a localized region of the Kiel diagram wherein lithium is severely depleted. We discovered that stars in these two groups show similar trends in the A (Li)–[Fe/H] plane, but with a roughly constant offset in A (Li) of |$0.4\, \mathrm{dex}$|⁠ , the warm group having higher Li abundances. At |$\rm [Fe/H]\gtrsim -0.5$|⁠ , a significant increase in Li abundance with increasing metallicity is evident in both groups, signalling the onset of significant Galactic production. At lower metallicity, stars in the cool group sit on the Spite plateau, showing a reduced lithium of around |$0.4\, \mathrm{dex}$| relative to the primordial value predicted from big bang nucleosynthesis (BBN). However, stars in the warm group between [Fe/H] = −1.0 and −0.5 form an elevated plateau that is largely consistent with the BBN prediction. This may indicate that these stars in fact preserve the primordial Li produced in the early Universe. [ABSTRACT FROM AUTHOR]

Published
2020
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