Combined APOGEE-GALAH stellar catalogues using the Cannon

Nandakumar, Govind and Hayden, Michael R. and Sharma, Sanjib and Buder, Sven and Asplund, Martin and Bland-Hawthorn, Joss and De Silva, Gayandhi M. and D'Orazi, Valentina and Freeman, Ken C. and Kos, Janez and Lewis, Geraint F. and Martell, Sarah L. and Schlesinger, Katharine J. and Lin, Jane and Simpson, Jeffrey D. and Zucker, Daniel B. and Zwitter, Tomaž and Nordlander, Thomas and Casagrande, Luca and Lind, Karin and Cotar, Klemen and Stello, Dennis and Wittenmyer, Robert A. and Tepper-Garcia, Thor (2022) Combined APOGEE-GALAH stellar catalogues using the Cannon. Monthly Notices of the Royal Astronomical Society, 513 (1). pp. 232-255. ISSN 0035-8711

[img]
Preview
Text (Published Version)
stac873.pdf

Download (4MB) | Preview

Abstract

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 million stars in the Milky Way. Both surveys observe in different wavelength regimes and use different data reduction pipelines leading to significant offsets and trends in stellar parameters and abundances for the common stars observed in both surveys. Such systematic differences/offsets in stellar parameters and abundances make it difficult to effectively utilize them to investigate Galactic abundance trends in spite of the unique advantage provided by their complementary sky coverage and different Milky Way components they observe. Hence, we use the Cannon data-driven method selecting a training set of 4418 common stars observed by both surveys. This enables the construction of two catalogues, one with the APOGEE-scaled and the other with the GALAH-scaled stellar parameters. Using repeat observations in APOGEE and GALAH, we find high precision in metallicity (~0.02-0.4 dex) and alpha abundances (~0.02-0.03 dex) for spectra with good signal-to-noise ratio (SNR > 80 for APOGEE and SNR > 40 for GALAH). We use open and globular clusters to validate our parameter estimates and find small scatter in metallicity (0.06 dex) and alpha abundances (0.03 dex) in APOGEE-scaled case. The final catalogues have been cross-matched with the Gaia EDR3 catalogue to enable their use to carry out detailed chemo-dynamic studies of the Milky Way from perspectives of APOGEE and GALAH.


Statistics for USQ ePrint 49482
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: File reproduced in accordance with the copyright policy of the publisher/author.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -)
Date Deposited: 17 Jul 2022 23:36
Last Modified: 17 Jul 2022 23:36
Uncontrolled Keywords: surveys; stars: abundances; Galaxy: disc; Galaxy: evolution; Galaxy:; formation; Galaxy: structure
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Socio-Economic Objectives (2020): 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280120 Expanding knowledge in the physical sciences
Identification Number or DOI: https://doi.org/10.1093/mnras/stac873
URI: http://eprints.usq.edu.au/id/eprint/49482

Actions (login required)

View Item Archive Repository Staff Only