Journal article
The GALAH survey: stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity
Monthly notices of the Royal Astronomical Society, Vol.478(1), pp.228-254
07/21/2018
DOI: 10.1093/mnras/sty865
Abstract
Using GALAH (GALactic Archaeology with HERMES) survey data of nearby stars, we look at how structure in the planar (u, v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars with distance d less than or similar to 1 kpc, the Hercules stream is most strongly seen in higher metallicity stars [Fe/H] > 0.2. The Hercules stream peak v value depends on viewed galactic longitude, which we interpret as due to the gap between the stellar stream and more circular orbits being associated with a specific angular momentum value of about 16.40 km s(-1) kpc. The association of the gap with a particular angular momentum value supports a bar resonant model for the Hercules stream. Moving groups previously identified in Hipparcos (High Precision Parallax COllecting Satellite) observations are easiest to see in stars nearer than 250 pc, and their visibility and peak velocities in the velocity distributions depends on both viewing direction (galactic longitude and hemisphere) and metallicity. We infer that there is fine structure in local velocity distributions that varies over distances of a few hundred pc in the Galaxy.
Details
- Title: Subtitle
- The GALAH survey: stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity
- Creators
- Alice C. Quillen - University of RochesterGayandhi De Silva - The University of SydneySanjib Sharma - The University of SydneyMichael Hayden - ASTRO-3DKen Freeman - Australian National UniversityJoss Bland-Hawthorn - The University of SydneyMarusa Zerjal - Australian National UniversityMartin Asplund - ARC Centre of Excellence for All-sky AstrophysicsSven Buder - Max Planck Institute for AstronomyValentina D'Orazi - Ist Nazl Astrofis, Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, ItalyLy Duong - Australian National UniversityJanez Kos - The University of SydneyJane Lin - Australian National UniversityKarin Lind - Uppsala UniversitySarah Martell - UNSW SydneyKatharine Schlesinger - Australian National UniversityJeffrey D. Simpson - Australian Astronomical ObservatoryDaniel B. Zucker - Australian Astronomical ObservatoryTomaz Zwitter - University of LjubljanaBorja Anguiano - Macquarie UniversityDaniela Carollo - Osservatorio Astrofisico di TorinoLuca Casagrande - Australian National UniversityKlemen Cotar - University of LjubljanaPeter L. Cottrell - Monash UniversityMichael Ireland - Australian National UniversityPrajwal R. Kafle - International Centre for Radio Astronomy ResearchJonathan Horner - University of Southern QueenslandGeraint F. Lewis - The University of SydneyDavid M. Nataf - Johns Hopkins UniversityYuan-Sen Ting - Institute for Advanced StudyFred Watson - Australian Astronomical ObservatoryRob Wittenmyer - University of Southern QueenslandRosemary Wyse - Johns Hopkins University
- Resource Type
- Journal article
- Publication Details
- Monthly notices of the Royal Astronomical Society, Vol.478(1), pp.228-254
- DOI
- 10.1093/mnras/sty865
- ISSN
- 0035-8711
- eISSN
- 1365-2966
- Publisher
- Oxford Univ Press
- Number of pages
- 27
- Grant note
- Zonta International District 24 Simons Foundation CE170100013 / Australian Research Council (ARC) Centre of Excellence; Australian Research Council DP160103747 / ARC; Australian Research Council FT160100402 / ARC Future Fellowship; Australian Research Council Allan C. and Dorothy H. Davis Fellowship Miller Professorship from the Miller Institute, UC Berkeley DE140100598 / ARC through DE-CRA Fellowship; Australian Research Council Leibniz Institut fur Astrophysik Potsdam ARC Laureate Fellowship; Australian Research Council
- Language
- English
- Date published
- 07/21/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701731802771
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