Galaxy Groups from Large Redshift Surveys

ARIEL ZANDIVAREZ

New Research on Astrophysics, Neutron Stars and Galaxy Clusters

Nova Science Publishers

Lugar: New York; Año: 2007; p. 115 - 146

In the latest years the galactic and extragalactic astronomy have shown a veryimportant advance. This is mainly due to the recent construction of the greatest redshift surveys, the 2dF Galaxy Redshift Survey and the Sloan Digital Sky Survey, which have improved and increased the observational data.The large amount of information about physical properties and spatial distribution of galaxies allows carry out many important statistical studieswith reliables results. Moreover, having quality information about galaxydistribution is very important in order to understand the underlying distribution of galaxy systems. Historically, studies about galaxy systems were based on the galaxy clusters without take into account the poorersystems, owing to difficulties in the identification process. This poor systems, the groups of galaxies, are the linking chain between the distributionof galaxies in the field and the large cluster of galaxies. Consequently,the main topic of the present work are the groups of galaxies. We concentratein some of the statistical results obtained for the first and final releaseof the 2dF Galaxy Redshift Survey and the first ans second data Release of theSloan Digital Sky Survey. We explore issues like star formation, luminosity and mass functions, density profiles and environmental effects. We also describe the results obtained using the groups of galaxies as tracers of thelarge scale of the universe by means of statistical tools like the powerspectrum and the two point correlation function. We also perform newestimations almost in all these field, trying to contribute with newreliables results to the previous estimations.