1997/03/16 by Y. K. Ng, Ng, Y. K.
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.astro-ph/9703101
openalex publication_date 1997/03/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Part of the mystery around the Bulge carbon stars from Azzopardi et al. (1991) is solved, if they are related to the Sagittarius dwarf galaxy. The carbon stars are in that case not metal-rich as previously thought, but they have a metallicity comparable to the LMC, with an age between 0.1 to 1 Gyr. A significant fraction of the carbon stars still have luminosities fainter than the lower LMC limit of Mbol~-3.5. A similar trend is present among some of the carbon stars found in other dwarf spheroidals, but they do not reach a limit as faint as Mbol~-1.4 found for the SMC. At present, the TP-AGB evolution models cannot explain the origin of carbon stars with Mbol>-3.5 through a single-star evolution scenario, even if they form immediately after entering the TP-AGB phase. Mass transfer through binary evolution is suggested as a possible scenario to explain the origin of these low luminosity carbon stars.