INVESTIGADORES
PIATTI Andres Eduardo
artículos
Título:
A revised DDO abundance calibration for population I red giants
Autor/es:
PIATTI, ANDRÉS E.; CLARIA OLMEDO, JUAN JOSÉ; MINNITI, DANTE
Revista:
J. Astrophysics & Astronomy
Referencias:
Año: 1993 vol. 14 p. 145 - 165
Resumen:
Several arguments that justify establishing a revised abundance
calibration for DDO photometry of population I red giants are presented.
The components of the blanketing vector in the DDO C(45-48) vs C(42-45)
diagram are determined for late-type dwarfs and giants. We have
redefined the DDO cyanogen anomaly and calibrated it against
metallicity. The sample of field giants now available with abundances
derived from high dispersion spectroscopy is substantially larger than
previously available, leading to a more accurate abundance calibration.
Iso-abundance lines in the C(41-42) vs C(42-45) diagram have been
determined for population IG and K giants and an iterative method for
deriving abundances of these stars is described. We show that the new
DDO abundances are in very good agreement with those derived from high
dispersion spectroscopy. The new method improves by about 0.1 dex the
DDO abundances derived for early G and/or late K giants, with respect to
the delta(CN) method of Janes (1975).