Publications (38)
The GALAH+ Survey: A New Library of Observed Stellar Spectra Improves Radial Velocities and Hints at Motions within M67
Tomaž Zwitter, Janez Kos, Sven Buder +25
GALAH+ is a magnitude-limited survey of high resolution stellar spectra obtained by the HERMES spectrograph at the Australian Astronomical Observatory. Its third data release provi…
The GALAH Survey: Chemodynamics of the Solar Neighbourhood
Michael R. Hayden, Joss Bland-Hawthorn, Sanjib Sharma +13
We present the chemodynamic structure of the solar neighbourhood using 62 814 stars within a 500 pc sphere of the Sun observed by GALAH and with astrometric parameters from Gaia DR…
The GALAH Survey: No chemical evidence of an extragalactic origin for the Nyx stream
Daniel B. Zucker, Jeffrey D. Simpson, Sarah L. Martell +20
The results from the ESA Gaia astrometric mission and deep photometric surveys have revolutionized our knowledge of the Milky Way. There are many ongoing efforts to search these da…
The GALAH Survey: Verifying abundance trends in the open cluster M67 using non-LTE spectroscopy
Xudong Gao, Karin Lind, Anish M. Amarsi +28
Open cluster members are coeval and share the same initial bulk chemical compositions. Consequently, differences in surface abundances between members of a cluster that are at diff…
The GALAH+ Survey: Third Data Release
Sven Buder, Sanjib Sharma, Janez Kos +44
The ensemble of chemical element abundance measurements for stars, along with precision distances and orbit properties, provides high-dimensional data to study the evolution of the…
The GALAH survey: unresolved triple Sun-like stars discovered by the Gaia mission
Klemen Äotar, Tomaž Zwitter, Gregor Traven +16
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 inves…
The GALAH survey and Gaia DR2: dissecting the stellar disc's phase space by age, action, chemistry and location
Joss Bland-Hawthorn, Sanjib Sharma, Thor Tepper-Garcia +24
We use the second data releases of the ESA Gaia astrometric survey and the high-resolution GALAH spectroscopic survey to analyse the structure of our Galaxy's disc components. With…
The GALAH survey: Chemical Tagging of Star Clusters and New Members in the Pleiades
Janez Kos, Joss Bland-Hawthorn, Ken Freeman +25
The technique of chemical tagging uses the elemental abundances of stellar atmospheres to `reconstruct' chemically homogeneous star clusters that have long since dispersed. The GAL…
The K2-HERMES Survey. I. Planet Candidate Properties from K2 Campaigns 1-3
Robert A. Wittenmyer, Sanjib Sharma, Dennis Stello +31
Accurate and precise radius estimates of transiting exoplanets are critical for understanding their compositions and formation mechanisms. To know the planet, we must know the host…
The GALAH Survey: Improving our understanding of confirmed and candidate planetary systems with large stellar surveys
Jake T. Clark, Duncan J. Wright, Robert A. Wittenmyer +24
Pioneering photometric, astrometric, and spectroscopic surveys are helping exoplanetary scientists better constrain the fundamental properties of stars within our galaxy, and the p…
The GALAH survey: tracing the Galactic disk with Open Clusters
Lorenzo Spina, Yuan-Sen Ting, Gayandhi M. De Silva +28
Open clusters are unique tracers of the history of our own Galaxy's disk. According to our membership analysis based on \textit{Gaia} astrometry, out of the 226 potential clusters…
The TESS-HERMES survey Data Release 1: high-resolution spectroscopy of the TESS southern continuous viewing zone
Sanjib Sharma, Dennis Stello, Sven Buder +22
The Transiting Exoplanet Survey Satellite (TESS) will provide high precision time-series photometry for millions of stars with at least a half-hour cadence. Of particular interest…
Fundamental relations for the velocity dispersion of stars in the Milky Way
Sanjib Sharma, Michael R. Hayden, Joss Bland-Hawthorn +34
We explore the fundamental relations governing the radial and vertical velocity dispersions of stars in the Milky Way, from combined studies of complementary surveys including GALA…
Cost-Optimal Foundation Model Deployment Portfolio for Transportation Management
Xi Cheng, Ke Liu, Siyuan Feng +2
The paper formulates and solves a cost‑optimal deployment problem for foundation models in transportation management centers, balancing quality, latency, safety, and GPU budget con…
The GALAH Survey: Velocity fluctuations in the Milky Way using red clump giants
Shourya Khanna, Sanjib Sharma, Joss Bland-Hawthorn +20
If the Galaxy is axisymmetric and in dynamical equilibrium, we expect negligible fluctuations in the residual line-of-sight velocity field. Recent results using the \apg{} survey f…
The vertical metallicity gradients of mono-age stellar populations in the Milky Way with the RAVE and Gaia data
Ioana CiucÄ, Daisuke Kawata, Jane Lin +3
We investigate the vertical metallicity gradients of five mono-age stellar populations between 0 and 11 Gyr for a sample of 18 435 dwarf stars selected from the cross-matched Tycho…
Confirming known planetary trends using a photometrically selected Kepler sample
Jonah T. Hansen, Luca Casagrande, Michael J. Ireland +1
Statistical studies of exoplanets and the properties of their host stars have been critical to informing models of planet formation. Numerous trends have arisen in particular from…
The GALAH Survey: Temporal Chemical Enrichment of the Galactic Disk
Jane Lin, Martin Asplund, Yuan-Sen Ting +22
We present isochrone ages and initial bulk metallicities (, by accounting for diffusion) of 163,722 stars from the GALAH Data Release 2, mainly composed of main…
Combined APOGEE-GALAH stellar catalogues using the Cannon
Govind Nandakumar, Michael R. Hayden, Sanjib Sharma +21
APOGEE and GALAH are two high resolution multi-object spectroscopic surveys that provide fundamental stellar parameters and multiple elemental abundance estimates for about half a…
The GALAH Survey: Chemical Clocks
Michael R. Hayden, Sanjib Sharma, Joss Bland-Hawthorn +27
Previous studies have found that the elemental abundances of a star correlate directly with its age and metallicity. Using this knowledge, we derive ages for a sample of 250,000 st…
Stellar ages and masses in the solar neighbourhood: Bayesian analysis using spectroscopy and Gaia DR1 parallaxes
Jane Lin, Aaron Dotter, Yuan-Sen Ting +1
We present a Bayesian implementation of isochrone fitting in deriving stellar ages and masses, incorporating absolute K magnitude () derived from 2MASS photometry and Gaia…
The GALAH Survey: Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere and metallicity
Alice C. Quillen, Gayandhi De Silva, Sanjib Sharma +30
Using GALAH 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 ne…
K2-HERMES II. Planet-candidate properties from K2 Campaigns 1-13
Robert A. Wittenmyer, Jake T. Clark, Sanjib Sharma +22
Accurate and precise radius estimates of transiting exoplanets are critical for understanding their compositions and formation mechanisms. To know the planet, we must know the host…
The GALAH Survey and Gaia DR2: (Non)existence of five sparse high-latitude open clusters
Janez Kos, Gayandhi de Silva, Joss Bland-Hawthorn +21
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 forma…
The GALAH and TESS-HERMES surveys: high-resolution spectroscopy of luminous supergiants in the Magellanic Clouds and Bridge
Jeffrey D. Simpson, Dennis Stello, Sanjib Sharma +24
We report the serendipitous observations of 571 luminous supergiants in the Magellanic Clouds by the spectroscopic GALAH and TESS-HERMES surveys: 434 stars in the Large Magellanic…
Discovery of a 21 Myr old stellar population in the Orion complex
Janez Kos, Joss Bland-Hawthorn, Martin Asplund +12
The Orion complex is arguably the most studied star-forming region in the Galaxy. While stars are still being born in the Orion nebula, the oldest part was believed to be no more t…
The GALAH Survey: A New Sample of Extremely Metal-Poor Stars Using A Machine Learning Classification Algorithm
Arvind C. N. Hughes, Lee R. Spitler, Daniel B. Zucker +21
Extremely Metal-Poor (EMP) stars provide a valuable probe of early chemical enrichment in the Milky Way. Here we leverage a large sample of high-resolution stellar sp…
The GALAH survey: The data reduction pipeline
Janez Kos, Jane Lin, Tomaž Zwitter +29
We present the data reduction procedures being used by the GALAH survey, carried out with the HERMES fibre-fed, multi-object spectrograph on the 3.9~m Anglo-Australian Telescope. G…
The GALAH Survey: Using Galactic Archaeology to Refine our Knowledge of TESS Target Stars
Jake T. Clark, Mathieu Clerte, Natalie R. Hinkel +29
An unprecedented number of exoplanets are being discovered by the Transiting Exoplanet Survey Satellite (TESS). Determining the orbital parameters of these exoplanets, and especial…
The GALAH Survey: Dependence of elemental abundances on age and metallicity for stars in the Galactic disc
Sanjib Sharma, Michael R. Hayden, Joss Bland-Hawthorn +24
Using data from the GALAH survey, we explore the dependence of elemental abundances on stellar age and metallicity among Galactic disc stars. We find that the abundance of most ele…
The K2-HERMES Survey: Age and Metallicity of the Thick Disc
Sanjib Sharma, Dennis Stello, Joss Bland-Hawthorn +34
Asteroseismology is a promising tool to study Galactic structure and evolution because it can probe the ages of stars. Earlier attempts comparing seismic data from the {\it Kepler}…
The GALAH Survey: Chemical tagging and chrono-chemodynamics of accreted halo stars with GALAH+ DR3 and eDR3
Sven Buder, Karin Lind, Melissa K. Ness +27
Since the advent of astrometry, it is possible to identify massive accreted systems within the Galaxy through their unique dynamical signatures. One such system, -Saus…
The GALAH survey: Co-orbiting stars and chemical tagging
Jeffrey D. Simpson, Sarah L. Martell, Gary Da Costa +24
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 2017. They identifie…
The GALAH Survey: Accurate Radial Velocities and Library of Observed Stellar Template Spectra
Tomaž Zwitter, Janez Kos, Andrea Chiavassa +34
GALAH is a large-scale magnitude-limited southern stellar spectroscopic survey. Its second data release (GALAH DR2) provides values of stellar parameters and abundances of 23 eleme…
The GALAH Survey: Observational Overview and Gaia DR1 companion
Sarah Martell, Sanjib Sharma, Sven Buder +30
The Galactic Archaeology with HERMES (GALAH) Survey is a massive observational project to trace the Milky Way's history of star formation, chemical enrichment, stellar migration an…
Holistic spectroscopy: Complete reconstruction of a wide-field, multi-object spectroscopic image using a photonic comb
Janez Kos, Joss Bland-Hawthorn, Christopher H. Betters +18
The primary goal of Galactic archaeology is to learn about the origin of the Milky Way from the detailed chemistry and kinematics of millions of stars. Wide-field multi-fibre spect…
Measuring 14 elemental abundances with R=1,800 LAMOST spectra
Yuan-Sen Ting, Hans-Walter Rix, Charlie Conroy +2
The LAMOST survey has acquired low-resolution spectra (R=1,800) for 5 million stars across the Milky Way, far more than any current stellar survey at a corresponding or higher spec…
The GALAH survey and Gaia DR2: Linking ridges, arches and vertical waves in the kinematics of the Milky Way
Shourya Khanna, Sanjib Sharma, Thor Tepper-Garcia +15
Gaia DR2 has revealed new small-scale and large-scale patterns in the phase-space distribution of stars in the Milky Way. In cylindrical Galactic coordinates , ridge-like…