Luminosity functions and the evolution of low-mass population I giants

Journal Article · Tue Jun 01 04:00:00 EDT 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154408· OSTI ID:7178881

Tinsley, B M; Gunn, J E

Luminosity functions in terms of bolometric magnitudes are constructed for M67 and for two samples of old-disk field giants. These are compared with theoretical rates of evolution on the giant branch. M67 has too few stars to give a useful comparison. The field giants show good agreement with theory, and the number of stars at the ''clump'' suggests that core helium-burning is prolonged by overshoot with semiconvective mixing. The fuel consumption derived from the luminosity functions is consistent with core helium ignition at the theortically predicted core mass, and with a final core mass in agreement with observed white dwarf masses. Data are needed for a larger complete sample of field giants for the luminosity function to be better determined. Further details, especially for the variable M giants at the top of the giant branch, are needed for population syntheses of elliptical galaxies. (AIP)

• Research Organization: Lick Observatory, Board of Study in Astronomy and Astrophysics, University of California, Santa Cruz
• OSTI ID: 7178881
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 206:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CONVECTION
CRYOGENIC FLUIDS
ELEMENTS
ENERGY TRANSFER
FLUIDS
GIANT STARS
HEAT TRANSFER
HELIUM
LUMINOSITY
MASS
NONMETALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RARE GASES
STAR EVOLUTION
STARS