Carbon stars in the X-Shooter Spectral Library

A. Gonneau*, A. Lancon, S. C. Trager, B. Aringer, M. Lyubenova, W. Nowotny, R. F. Peletier, P. Prugniel, Y. -P. Chen, M. Dries, O. S. Choudhury, J. Falcon-Barroso, M. Koleva, S. Meneses-Goytia, P. Sanchez-Blazquez, A. Vazdekis

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

13 Citations (Scopus)
224 Downloads (Pure)

Abstract

We provide a new collection of spectra of 35 carbon stars obtained with the ESO/VLT X-Shooter instrument as part of the X-Shooter Spectral Library project. The spectra extend from 0.3 mu m to 2.4 mu m with a resolving power above similar to 8000. The sample contains stars with a broad range of (J-K) color and pulsation properties located in the Milky Way and the Magellanic Clouds.

We show that the distribution of spectral properties of carbon stars at a given (J-K) color becomes bimodal (in our sample) when (J-K) is larger than about 1.5. We describe the two families of spectra that emerge, characterized by the presence or absence of the absorption feature at 1.53 mu m, generally associated with HCN and C2H2. This feature appears essentially only in large-amplitude variables, though not in all observations. Associated spectral signatures that we interpret as the result of veiling by circumstellar matter, indicate that the 1.53 mu m feature might point to episodes of dust production in carbon-rich Miras.

Original languageEnglish
Article number36
Number of pages26
JournalAstronomy & astrophysics
Volume589
Issue numberMay 2016
DOIs
Publication statusPublished - May-2016

Keywords

  • stars: AGB and post-AGB
  • stars: carbon
  • infrared: stars
  • ultraviolet: stars
  • ASYMPTOTIC GIANT BRANCH
  • SMALL-MAGELLANIC-CLOUD
  • LONG-PERIOD VARIABLES
  • NEAR-INFRARED SPECTROSCOPY
  • GRAVITATIONAL LENSING EXPERIMENT.
  • AGE STELLAR POPULATIONS
  • POST-STARBURST GALAXIES
  • OGLE-III CATALOG
  • METAL-POOR STARS
  • 2.5 MU-M

Cite this