2006/09/13 by Judith G. Cohen, Scott Hsieh, Stanimir Metchev +3 · 4 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Brightness #Distance modulus #Galaxy #Globular cluster #Infrared #Metallicity #Photometry (optics) #Physics #Sky #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/509127
Accepted for publication in the AJ
arxiv created 2006/09/13 · openalex publication_date 2006/12/04 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have mosaicked Two Micron All Sky Survey (2MASS) images to derive surface brightness profiles in J , H , and K s for 104 Galactic globular clusters. We fit these with King profiles and show that the core radii are identical to within the errors for each of these IR colors and are identical to the core radii at V in essentially all cases. We derive integrated-light colors V - J , V - H , V - K s , J - H , and J - K s for these globular clusters. Each color shows a reasonably tight relation between the dereddened colors and metallicity. Fits to these are given for each color. The IR - IR colors have very small errors, due largely to the all-sky photometric calibration of the 2MASS survey, while the V - IR colors have substantially larger uncertainties. We find fairly good agreement with measurements of integrated-light colors for a smaller sample of Galactic globular clusters by M. Aaronson, M. Malkan, and D. Kleinmann from 1977. Our results provide a calibration for the integrated light of distant single-burst old stellar populations from very low to solar metallicities. A comparison of our dereddened measured colors with predictions from several models of the integrated light of single-burst old populations shows good agreement in the low-metallicity domain for V - K s colors but also shows an offset at a fixed [Fe/H] of ∼0.1 mag in J - K s , which we ascribe to photometric system transformation issues. Some of the models fail to reproduce the behavior of the integrated-light colors of the Galactic globular clusters near solar metallicity.