Bibcode
Whitlock, Shannon; Forbes, Duncan A.; Beasley, Michael A.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 345, Issue 3, pp. 949-959.
Fecha de publicación:
11
2003
Número de citas
8
Número de citas referidas
8
Descripción
We present wide-area UBRI photometry for globular clusters around the
Leo group galaxy NGC 3379. Globular cluster candidates are selected from
their B-band magnitudes and their (U-B)o versus
(B-I)o colours. A colour-colour selection region was defined
from photometry of the Milky Way and M31 globular cluster systems. We
detect 133 globular cluster candidates, which supports previous claims
of a low specific frequency for NGC 3379.
The Milky Way and M31 reveal blue and red subpopulations, with
(U-B)o and (B-I)o colours indicating mean
metallicities similar to those expected based on previous spectroscopic
work. The stellar population models of Maraston and Brocato et al. are
consistent with both subpopulations being old, and with metallicities of
[Fe/H]~-1.5 and -0.6 for the blue and red subpopulations, respectively.
The models of Worthey do not reproduce the (U-B)o colours of
the red (metal-rich) subpopulation for any modelled age.
For NGC 3379 we detect a blue subpopulation with similar colours, and
presumably age/metallicity, to that of the Milky Way and M31 globular
cluster systems. The red subpopulation is less well defined, perhaps due
to increased photometric errors, but indicates a mean metallicity of
[Fe/H]~-0.6.