Journal article
The GALAH Survey: second data release
Monthly notices of the Royal Astronomical Society, Vol.478(4), pp.4513-4552
08/21/2018
DOI: 10.1093/mnras/sty1281
Abstract
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 (Teff, log g, [Fe/H], [X/Fe], vmic, vsin i, $A_{K_S}$) 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.
Details
- Title: Subtitle
- The GALAH Survey: second data release
- Creators
- Sven Buder - Heidelberg UniversityMartin Asplund - ARC Centre of Excellence for All-sky AstrophysicsLy Duong - Australian National UniversityJanez Kos - The University of SydneyKarin Lind - Uppsala UniversityMelissa K Ness - Columbia UniversitySanjib Sharma - The University of SydneyJoss Bland-Hawthorn - Cancer Genomics CentreAndrew R Casey - Monash UniversityGayandhi M De Silva - The University of SydneyValentina D’Orazi - Osservatorio Astronomico di PadovaKen C Freeman - Australian National UniversityGeraint F Lewis - The University of SydneyJane Lin - Australian National UniversitySarah L Martell - UNSW SydneyKatharine J Schlesinger - Australian National UniversityJeffrey D Simpson - Australian Astronomical ObservatoryDaniel B Zucker - Macquarie UniversityTomaž Zwitter - University of LjubljanaAnish M Amarsi - Max Planck Institute for AstronomyBorja Anguiano - University of VirginiaDaniela Carollo - Osservatorio Astrofisico di TorinoLuca Casagrande - ARC Centre of Excellence for All-sky AstrophysicsKlemen Čotar - University of LjubljanaPeter L Cottrell - Monash UniversityGary Da Costa - University of CanberraXudong D Gao - Max Planck Institute for AstronomyMichael R Hayden - The University of SydneyJonathan Horner - University of Southern QueenslandMichael J Ireland - Australian National UniversityPrajwal R Kafle - International Centre for Radio Astronomy ResearchUlisse Munari - Osservatorio Astronomico di PadovaDavid M Nataf - Johns Hopkins UniversityThomas Nordlander - ARC Centre of Excellence for All-sky AstrophysicsDennis Stello - UNSW SydneyYuan-Sen Ting (丁源森) - Institute for Advanced Study, Princeton, NJ 08540, USAGregor Traven - University of LjubljanaFred Watson - Australian Astronomical ObservatoryRobert A Wittenmyer - University of Southern QueenslandRosemary F G Wyse - Johns Hopkins UniversityDavid Yong - Australian National UniversityJoel C Zinn - The Ohio State UniversityMaruša Žerjal - Australian National UniversityGALAH Collaboration
- Resource Type
- Journal article
- Publication Details
- Monthly notices of the Royal Astronomical Society, Vol.478(4), pp.4513-4552
- DOI
- 10.1093/mnras/sty1281
- ISSN
- 0035-8711
- eISSN
- 1365-2966
- Publisher
- Oxford University Press
- Number of pages
- 40
- Grant note
- FL110100012; DP160103747; DP150104667; 2015-00415_3 / Australian Research Council (10.13039/501100000923) A/2013B/13; A/2014A/25; A/2015A/19; A2017A/18 / Australian Astronomical Observatory (10.13039/501100004661)
- Language
- English
- Date published
- 08/21/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701732602771
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