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Дата изменения: Fri Nov 10 16:38:46 2006
Дата индексирования: Mon Oct 1 22:24:02 2012
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GCSs and dwarf galaxies in the Fornax Cluster

Here you can see an image of the central part of the Fornax Cluster taken from the Digital Sky Survey. The marked squares indicate the observed CCD fields that we selected for our investigations.

And now follows what we have done and are doing with these fields:

  • We studied the globular cluster systems (GCSs) of 5 early type galaxies in the Fornax cluster: NGC 1374, NGC1379, NGC 1387, NGC 1427, and the central giant elliptical NGC 1399. We investigated the following properties of the GCSs: the number of GCs, the color and color distribution, as well as the radial and spatial distribution of GCs. NGC 1399 has an extraordinary rich GCS with a broad color distribution, whereas the other 4 galaxies have ``normal'' GCSs. See for more details our paper ``Globular cluster systems of early-type galaxies in Fornax'', 1997, A&A 319, 470 (as a gzipped .ps file of the preprint [343k]/please add ".gz" after downloading).
    The globular cluster luminosity function (GCLF) of these galaxies can be used as distance indicator. Applying the same method to other galaxy clusters one can get pretty accurate relative distances between the clusters. The absolute distance depends on the accuracy of the distance determination of GCs in our Milky Way and M31. See our paper ``The distance of the Fornax Cluster based on Globular Cluster Luminosity Functions'', 1996, A&A 309, L39 (as a gzipped .ps file of the preprint [76k], please add ".gz" after downloading).

  • We also studied the galaxy population in the observed fields. NGC 1399 is located in the dynamical center of the Fornax cluster and possesses a large extended cD halo. It is under discussion, if cD halos of central galaxies could be formed by the accretion of dwarf galaxies. The accretion of a large number of dwarf galaxies might also help to explain the extraordinarily rich GCSs of central dominant galaxies in clusters. See our papers ``The central region of the Fornax cluster - I. A catalog and photometric properties of galaxies in selected CCD fields'' and ``The central region of the Fornax cluster - II. Spectroscopy and radial velocities of member and background galaxies'' (as a gzipped .ps files [413kB and 268kB], please add ".gz" after downloading) and for the discussion of a dwarf galaxy infall scenario chapter 5 of my PhD thesis.

  • The Fornax cluster is dominated by early-type galaxies. One rare bird in the cluster center is the irregular galaxy NGC 1427A.
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