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Title: THE SIZE DIFFERENCE BETWEEN RED AND BLUE GLOBULAR CLUSTERS IS NOT DUE TO PROJECTION EFFECTS

Abstract

Metal-rich (red) globular clusters in massive galaxies are, on average, smaller than metal-poor (blue) globular clusters. One of the possible explanations for this phenomenon is that the two populations of clusters have different spatial distributions. We test this idea by comparing clusters observed in unusually deep, high signal-to-noise images of M87 with a simulated globular cluster population in which the red and blue clusters have different spatial distributions, matching the observations. We compare the overall distribution of cluster effective radii as well as the relationship between effective radius and galactocentric distance for both the observed and simulated red and blue sub-populations. We find that the different spatial distributions does not produce a significant size difference between the red and blue sub-populations as a whole or at a given galactocentric distance. These results suggest that the size difference between red and blue globular clusters is likely due to differences during formation or later evolution.

Authors:
; ;  [1]
  1. Department of Physics and Astronomy, McMaster University, Hamilton ON L8S 4M1 (Canada)
Publication Date:
OSTI Identifier:
22078439
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 759; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; DISTANCE; GALACTIC EVOLUTION; GALAXIES; IMAGES; METALS; SIGNAL-TO-NOISE RATIO; SPATIAL DISTRIBUTION; STAR CLUSTERS

Citation Formats

Webb, Jeremy J., Harris, William E., and Sills, Alison, E-mail: webbjj@mcmaster.ca. THE SIZE DIFFERENCE BETWEEN RED AND BLUE GLOBULAR CLUSTERS IS NOT DUE TO PROJECTION EFFECTS. United States: N. p., 2012. Web. doi:10.1088/2041-8205/759/2/L39.
Webb, Jeremy J., Harris, William E., & Sills, Alison, E-mail: webbjj@mcmaster.ca. THE SIZE DIFFERENCE BETWEEN RED AND BLUE GLOBULAR CLUSTERS IS NOT DUE TO PROJECTION EFFECTS. United States. doi:10.1088/2041-8205/759/2/L39.
Webb, Jeremy J., Harris, William E., and Sills, Alison, E-mail: webbjj@mcmaster.ca. Sat . "THE SIZE DIFFERENCE BETWEEN RED AND BLUE GLOBULAR CLUSTERS IS NOT DUE TO PROJECTION EFFECTS". United States. doi:10.1088/2041-8205/759/2/L39.
@article{osti_22078439,
title = {THE SIZE DIFFERENCE BETWEEN RED AND BLUE GLOBULAR CLUSTERS IS NOT DUE TO PROJECTION EFFECTS},
author = {Webb, Jeremy J. and Harris, William E. and Sills, Alison, E-mail: webbjj@mcmaster.ca},
abstractNote = {Metal-rich (red) globular clusters in massive galaxies are, on average, smaller than metal-poor (blue) globular clusters. One of the possible explanations for this phenomenon is that the two populations of clusters have different spatial distributions. We test this idea by comparing clusters observed in unusually deep, high signal-to-noise images of M87 with a simulated globular cluster population in which the red and blue clusters have different spatial distributions, matching the observations. We compare the overall distribution of cluster effective radii as well as the relationship between effective radius and galactocentric distance for both the observed and simulated red and blue sub-populations. We find that the different spatial distributions does not produce a significant size difference between the red and blue sub-populations as a whole or at a given galactocentric distance. These results suggest that the size difference between red and blue globular clusters is likely due to differences during formation or later evolution.},
doi = {10.1088/2041-8205/759/2/L39},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}