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Title: K{sub s} -BAND LUMINOSITY EVOLUTION OF THE ASYMPTOTIC GIANT BRANCH POPULATION BASED ON STAR CLUSTERS IN THE LARGE MAGELLANIC CLOUD

We present a study of K{sub s} -band luminosity evolution of the asymptotic giant branch (AGB) population in simple stellar systems using star clusters in the Large Magellanic Cloud (LMC). We determine physical parameters of LMC star clusters including center coordinates, radii, and foreground reddenings. Ages of 83 star clusters are derived from isochrone fitting with the Padova models, and those of 19 star clusters are taken from the literature. The AGB stars in 102 star clusters with log(age) = 7.3-9.5 are selected using near-infrared color-magnitude diagrams based on Two Micron All Sky Survey photometry. Then we obtain the K{sub s} -band luminosity fraction of AGB stars in these star clusters as a function of ages. The K{sub s} -band luminosity fraction of AGB stars increases, on average, as age increases from log(age) ∼ 8.0, reaching a maximum at log(age) ∼ 8.5, and it decreases thereafter. There is a large scatter in the AGB luminosity fraction for given ages, which is mainly due to stochastic effects. We discuss this result in comparison with five simple stellar population models. The maximum K{sub s} -band AGB luminosity fraction for bright clusters is reproduced by the models that expect the value of 0.7-0.8more » at log(age) = 8.5-8.7. We discuss the implication of our results with regard to the study of size and mass evolution of galaxies.« less
Authors:
; ;  [1]
  1. Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22270649
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 777; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; ASYMPTOTIC SOLUTIONS; COLOR; COMPARATIVE EVALUATIONS; GALACTIC EVOLUTION; GIANT STARS; LUMINOSITY; MAGELLANIC CLOUDS; PHOTOMETRY; STAR CLUSTERS; STAR EVOLUTION; STOCHASTIC PROCESSES