Properties of the Dwarf Galaxy Population in Galaxy Clusters

Sánchez-Janssen, R.; Aguerri, J. Alfonso L.; Muñoz-Tuñón, C.
Bibliographical reference

The Astrophysical Journal, Volume 679, Issue 2, pp. L77-L80.

Advertised on:
6
2008
Number of authors
3
IAC number of authors
3
Citations
31
Refereed citations
30
Description
We present the observational properties of the dwarf galaxy population (Mr>M*r+1) corresponding to one of the largest samples of spectroscopically confirmed nearby galaxy cluster members reported in the literature. We have observed that red dwarf galaxies (u-r>2.22) share the same cluster environment as the brightest cluster members (Mr<-21), but are not in dynamical equilibrium. We computed the dwarf-to-giant ratio (DGR) using a spectroscopically selected sample. The DGR was found to vary with clustercentric distance, essentially due to the blue dwarf population (u-r<2.22). The u-r color of red dwarf galaxies was independent of their environment and similar to the color of red isolated dwarfs. Blue dwarf galaxies located outside r200 show similar u-r colors to those of the field population, while strong reddening was observed toward the cluster center. We also present evidence that the fraction of red to blue dwarf galaxies in clusters is larger in the innermost cluster regions. We conclude that the present red dwarf population observed in the central regions of nearby galaxy clusters could be related to the blue dwarf population observed in clusters at high redshift.
Related projects
Abell 370 is located approximately 4 billion light-years away in the constellation Cetus, the Sea Monster
Galaxy Evolution in Clusters of Galaxies
Galaxies in the universe can be located in different environments, some of them are isolated or in low density regions and they are usually called field galaxies. The others can be located in galaxy associations, going from loose groups to clusters or even superclusters of galaxies. One of the foremost challenges of the modern Astrophysics is to
Jairo
Méndez Abreu