The GALAH Survey: Chemically tagging the Fimbulthul stream to the globular cluster ω Centauri

Simpson, Jeffrey D. and Martell, Sarah L. and Da Costa, Gary and Horner, Jonathan and Wyse, Rosemary F. G. and Ting, Yuan-Sen and Asplund, Martin and Bland-Hawthorn, Joss and Buder, Sven and de Silva, Gayandhi M. and Freeman, Ken C. and Kos, Janez and Lewis, Geraint F. and Lind, Karin and Sharma, Sanjib and Zucker, Daniel B. and Zwitter, Tomaz and Cotar, Klemen and Cottrell, Peter L. and Nordlander, Thomas (2020) The GALAH Survey: Chemically tagging the Fimbulthul stream to the globular cluster ω Centauri. Monthly Notices of the Royal Astronomical Society, 491 (3). pp. 3374-3384. ISSN 0035-8711

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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.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Access to Published version in accordance with the copyright policy of the publisher.
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: 14 Sep 2020 05:00
Last Modified: 30 Sep 2020 03:19
Uncontrolled Keywords: globular clusters: individual: ω Cen; galaxy: halo; galaxy: kinematics and dynamics; Astrophysics - Astrophysics of Galaxies
Fields of Research (2008): 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
Identification Number or DOI: https://doi.org/10.1093/mnras/stz3105
URI: http://eprints.usq.edu.au/id/eprint/39336

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