Preprint
The GALAH and TESS-HERMES surveys: high-resolution spectroscopy of luminous supergiants in the Magellanic Clouds and Bridge
ArXiv.org
Cornell University
04/19/2018
DOI: 10.48550/arxiv.1804.05900
Abstract
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 Cloud and 137 in the Small Magellanic Cloud. We also find one star that appears associated with structured star formation in the Magellanic Bridge. Both of these surveys are aimed at the local volume of the Galaxy but have simple, magnitude-limited selection functions that mean they include some observations of luminous extra-Galactic stars. The surveys determine stellar parameter and abundances using The Cannon, a data-driven generative modelling approach. In this work, we explore the results from The Cannon when it is fed the spectra of these intrinsically luminous supergiants in the Magellanic Clouds, which are well outside the normal bounds of The Cannon's training set. We find that, although the parameters are astrophysically incorrect, the vsini and the abundances of lithium, barium, and magnesium are excellent discriminants of these stars. It shows that in the future, with an expanded training set, it should be possible to determine accurate values for these types of stars.
Details
- Title: Subtitle
- The GALAH and TESS-HERMES surveys: high-resolution spectroscopy of luminous supergiants in the Magellanic Clouds and Bridge
- Creators
- Jeffrey D SimpsonDennis StelloSanjib SharmaYuan-Sen TingDavid M NatafGary Da CostaRobert A WittenmyerJonathan HornerSarah L MartellGeraint F LewisGayandhi M De SilvaPeter L CottrellMartin AsplundJoss Bland-HawthornSven BuderValentina D'OraziLy DuongKen C FreemanJanez KosJane LinKarin LindKatharine. J SchlesingerDaniel B ZuckerTomaž ZwitterPrajwal R KafleShourya KhannaThomas Nordlander
- Resource Type
- Preprint
- Publication Details
- ArXiv.org
- DOI
- 10.48550/arxiv.1804.05900
- ISSN
- 2331-8422
- Publisher
- Cornell University; Ithaca, New York
- Language
- English
- Date posted
- 04/19/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984702723502771
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