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 MoreMetadata
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)
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- Index Terms
- Spectroscopic ,
- Spectral Features ,
- Unsupervised Algorithm ,
- Strong Enhancement ,
- Star Rating ,
- Velocity Dispersion ,
- Training Set ,
- Idiosyncratic ,
- Dimensionality Reduction ,
- Supervised Learning ,
- Prominent Feature ,
- Telescope ,
- 2D Plane ,
- Classification Procedure ,
- Pilot Survey ,
- Molecular Bands ,
- Follow-up Observation ,
- Rest Frame ,
- Normal Spectrum ,
- t-SNE Projection ,
- Atomic Lines ,
- Degree Of Enhancement
- Author Keywords
Keywords assist with retrieval of results and provide a means to discovering other relevant content. Learn more.
- Index Terms
- Spectroscopic ,
- Spectral Features ,
- Unsupervised Algorithm ,
- Strong Enhancement ,
- Star Rating ,
- Velocity Dispersion ,
- Training Set ,
- Idiosyncratic ,
- Dimensionality Reduction ,
- Supervised Learning ,
- Prominent Feature ,
- Telescope ,
- 2D Plane ,
- Classification Procedure ,
- Pilot Survey ,
- Molecular Bands ,
- Follow-up Observation ,
- Rest Frame ,
- Normal Spectrum ,
- t-SNE Projection ,
- Atomic Lines ,
- Degree Of Enhancement
- Author Keywords