Bibcode
DOI
Marín-Franch, A.; Aparicio, A.
Bibliographical reference
The Astrophysical Journal, Volume 568, Issue 1, pp. 174-189.
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3
2002
Journal
Citations
21
Refereed citations
20
Description
Globular cluster systems of 17 elliptical galaxies have been studied in
the Coma Cluster of galaxies. Surface-brightness fluctuations have been
used to determine total populations of globular clusters, and specific
frequency (SN) has been evaluated for each individual galaxy.
Enormous differences in SN between similar galaxies are
found. In particular, SN results vary by an order of
magnitude from galaxy to galaxy. Extreme cases are the following: (1) at
the lower end of the range, NGC 4673 has SN=1.0+/-0.4, a
surprising value for an elliptical galaxy, but typical for spiral and
irregular galaxies; (2) at the upper extreme, MCG +5-31-063 has
SN=13.0+/-4.2 and IC 4051 has SN=12.7+/-3.2, and
they are more likely to belong to supergiant cD galaxies than to
``normal'' elliptical galaxies. Furthermore, NGC 4874, the central
supergiant cD galaxy of the Coma Cluster, also exhibits a relatively
high specific frequency (SN=9.0+/-2.2). The other galaxies
studied have SN in the range [2, 7], the mean value being
SN=5.1. No single scenario seems to account for the observed
specific frequencies, so the history of each galaxy must be deduced
individually by suitably combining the different models (in situ,
mergers, and accretions). The possibility that Coma is formed by several
subgroups is also considered. If only the galaxies of the main subgroup
defined by Gurzadyan & Mazure are used, a trend in SN
arises in the sense of SN being bigger in higher-density
regions. This result needs further confirmation.