NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-18 T13:24:43 PDT
Help | Comment | NED Home

For refcode 2001AJ....121.2974L:
Retrieve 17 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2001AJ....121.2974L PROPERTIES OF GLOBULAR CLUSTER SYSTEMS IN NEARBY EARLY-TYPE GALAXIES SOREN S. LARSEN AND JEAN P. BRODIE Lick Observatory, University of California, Santa Cruz, Department of Astronomy and Astrophysics, 477 Clark Kerr Hall, Santa Cruz, CA 95064; soeren@ucolick.org, brodie@ucolick.org JOHN P. HUCHRA Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 DUNCAN A. FORBES Astrophysics and Supercomputing, Swinburne University, Hawthorn VIC 3122, Australia AND CARL J. GRILLMAIR SIRTF Science Center, Mail Stop 100-22, California Institute of Technology, 770 South Wilson, Pasadena, CA 91125 Received 2000 November 24; accepted 2001 February 20 ABSTRACT We present a study of globular clusters (GCs) in 17 relatively nearby early-type galaxies, based on deep F555W and F814W images from the Wide Field Planetary Camera 2, on board the Hubble Space Telescope. A detailed analysis of color distributions, cluster sizes, and luminosity functions is performed and compared with GCs in the Milky Way. In nearly all cases, a KMM test returns a high confidence level for the hypothesis that a sum of two Gaussians provides a better fit to the observed color distribution than a single Gaussian, although histograms of the (V-I)0 distribution are not always obviously bimodal. The blue and red peak colors returned by the KMM test are both found to correlate with absolute host galaxy B-band magnitude and central velocity dispersion (at about the 2-3 {sigma} level). Red GCs are generally smaller than blue GCs by about 20%. The size difference is seen at all radii at least out to 4' and within sub-bins in (V-I)0 color, and exists also in the Milky Way and Sombrero (M104) spiral galaxies. Fitting t5 functions to the luminosity functions of blue and red GC populations separately, we find that the V-band turnover of the blue GCs is brighter than that of the red ones by about 0.3 mag on the average, as expected if the two GC populations have similar ages and mass distributions but different metallicities. Brighter than the turnover at M_V_ ~ -7.5, the luminosity functions (LFs) are well approximated by power laws with an exponent of about -1.75. This is similar to the LF for young star clusters, suggesting that young and old globular clusters form by the same basic mechanism. We discuss scenarios for GC formation and conclude that our data appear to favor in situ models in which all GCs in a galaxy formed after the main body of the protogalaxy had assembled into a single potential well. Key words: galaxies: elliptical and lenticular, cD-galaxies: evolution- galaxies: star clusters
Retrieve 17 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home