Submitting Campus
Daytona Beach
Department
Physical Sciences
Document Type
Article
Publication/Presentation Date
7-1996
Abstract/Description
Using HST and the WFPC2 we have acquired very deep V- and I-band photometry of stars in NGC 2420 and NGC 2477 to study cluster luminosity functions at approximately solar metallicity. We have determined these cluster luminosity functions down to MI = 10.5 (0.2 M⊙) and find that the luminosity function of NGC 2420 turns over at MI ≈ 9.0, and possibly stops altogether by MI ≈ 9.5. The luminosity function of NGC 2477 may flatten at MI ≥ 9.5. We compare our open cluster luminosity functions to the solar neighborhood field star luminosity function of Kroupa, Tout \& Gilmore (1993) and the four published HST globular cluster luminosity functions: ω Cen (Elson {\it et al.}\ 1995), 47 Tuc (De Marchi \& Paresce 1995b), M 15 (De Marchi \& Paresce 1995a), and NGC 6397 (Paresce, De Marchi \& Romaniello 1995). We find a smooth relation between the location of the luminosity function turn-over and the metallicity for all these low mass star samples which matches the expected MI versus [Fe/H] trend for a model star of ≈ 0.27 M⊙ (Saumon 1995; Alexander {\it et al.}\ 1996). We interpret this smooth and systematic behavior in the cluster luminosity functions as strong evidence in favor of an invariant initial mass function and a metallicity-dependent mass-luminosity relation.
Publication Title
The Astronomical journal
DOI
https://doi.org/10.1086/118000
Publisher
The American Astronomical Society, The Institute of Physics
Scholarly Commons Citation
von Hippel, T., Gilmore, G., Tanvir, N. R., Robinson, D., & Jones, D. H. (1996). The Metallicity Dependence of the Stellar Luminosity and Initial Mass Functions: HST Observations of Open and Globular Clusters. The Astronomical journal, 112(). https://doi.org/10.1086/118000
Additional Information
Dr. von Hippel was not affiliated with Embry-Riddle Aeronautical University at the time this paper was published.