The GALAH survey: a catalogue of carbon-enhanced stars and CEMP candidates | OUP Journals & Magazine | IEEE Xplore

The GALAH survey: a catalogue of carbon-enhanced stars and CEMP candidates

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Abstract:

Swan bands – characteristic molecular absorption features of the C2 molecule – are a spectroscopic signature of carbon-enhanced stars. They can also be used to identify c...Show More

Abstract:

Swan bands – characteristic molecular absorption features of the C2 molecule – are a spectroscopic signature of carbon-enhanced stars. They can also be used to identify carbon-enhanced metal-poor (CEMP) stars. The GALAH (GALactic Archaeology with Hermes) is a magnitude-limited survey of stars producing high-resolution, high-signal-to-noise spectra. We used 627 708 GALAH spectra to search for carbon-enhanced stars with a supervised and unsupervised classification algorithm, relying on the imprint of the Swan bands. We identified 918 carbon-enhanced stars, including 12 already described in the literature. An unbiased selection function of the GALAH survey allows us to perform a population study of carbon-enhanced stars. Most of them are giants, out of which we find 28 CEMP candidates. A large fraction of our carbon-enhanced stars with repeated observations show variation in radial velocity, hinting that there is a large fraction of variables among them. 32 of the detected stars also show strong Lithium enhancement in their spectra.
Published in: Monthly Notices of the Royal Astronomical Society ( Volume: 483, Issue: 3, November 2018)
Page(s): 3196 - 3212
Date of Publication: November 2018

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