Radial velocity distribution and line strengths of 33 carbon stars in the Galactic bulge

Abstract

This paper presents optical spectra of 33 carbon stars discovered by Azzopardi et al. (1985) in low-extinction windows to the Galactic bulge. From these spectra, the radial velocity distribution for the stars was obtained; the dispersion was found to be 113 + or - 14 km/sec (consistent with that of the bulge K and M giants) and the mean to be -44 + or - 20 km/sec. From the velocity distribution, it was found that the carbon stars do not share the kinematics of the local neighborhood and are likely to be genuine bulge members, making it possible to assign distances and accurate luminosities. Nineteen of the stars showed enhanced C-13, classifying them as J-star candidates. Two stars showed weak C2 absorption, classifying them as CS stars, and thirteen carbon stars appeared to be hydrogen-deficient. 63 refs.