| Issue |
A&A
Volume 405, Number 2, July II 2003
|
|
|---|---|---|
| Page(s) | 487 - 497 | |
| Section | Extragalactic astronomy | |
| DOI | https://doi.org/10.1051/0004-6361:20030598 | |
| Published online | 19 June 2003 | |
Extragalactic globular clusters in the near infrared III. NGC 5846 and NGC 7192 *,**
Quantifying the age distribution of sub-populations
1
European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
2
Sternwarte der Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
3
Sternwarte der Ludwigs-Maximilians-Universität, Scheinerstr. 1, 81679 München, Germany e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
4
Departamento de Astronomía y Astrofísica, P. Universidad Católica, Casilla 306, Santiago 22, Chile e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
5
Space Telescope Science Institute, Instrument Division, 3700 San Martin Drive, Baltimore MD 21218, USA e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Corresponding author: M. Hempel, This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
10
February
2003
Accepted:
18
April
2003
Abstract
In this third paper of our series on near-IR and optical photometry of
globular cluster systems in early-type galaxies we concentrate on the
photometric results for NGC 5846 and NGC 7192, two group ellipticals,
and on a first comparison between the globular cluster systems
investigated so far. In NGC 5846 the colour-colour diagram shows clear
bi-modality in 
, which is confirmed by a KMM test. The mean
colour of both peaks were estimated to be 
and 
. The
situation in NGC 7192 is different, in that the colour-colour diagram
gives no evidence for a distinct second population of globular
clusters. Using simulated colour distributions of globular cluster
systems, we make a first step in quantifying the cumulative age
distribution in globular cluster systems. Also here the result for
NGC 5846 leads us to the conclusion that its metal-rich globular
cluster population contains two globular cluster populations which
differ in age by several Gyr. The age structure for NGC 7192 shows
instead strong similarity with a single-age
population.
Key words: galaxies: star clusters / galaxies: individual: NGC 5846, NGC 7192
Based on observations at the Very Large Telescope of the European Southern Observatory, Chile (Program 63.N-0287).
Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the association of Universities for Research in Astronomy, Inc. under the NASA contract NAS 5-26555.
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.