List of Contributors

Instituto de Astrof sica de Canarias Spain Universidad Nacional de La Plata Argentina sbrough astro.swin.edu.au Carigi Leticia Instituto de Astronomia - UNAM Mexico carigi astroscu.unam.mx Cellone Sergio Universidad Nacional de La Plata Argentina University of Wisconsin-Madison chomiuk astro.wisc.edu Universidad Nacional de La Plata Argentina IATE, Obs. Astron. de Cordova Argentina Inst. de Astr.de La Plata, CONICET Argentina Universidad de Chile jcortes das.uchile.cl Instituto de Astronomia -...

Results

We catalogued 204 HI detections in the 16 groups, including 10 HI detections that did not match with any previously catalogued optical galaxy, and 11 HI detections that provided the redshift for previously catalogued galaxies, where the redshift was not previously known. Thus we find -10 new group members in our survey. Figure 1 shows a velocity-integrated HI intensity map of two of our galaxy groups, NGC 1407 and NGC 1332. The NGC 1407 group displays group 32m 24m 30m 16m Fig. 1....

The HI mass function

Recent large HI surveys have attempted to determine the low mass slope of the HI mass function. The authors in 9 used the 1000 brightest galaxies from the HI Parkes All-Sky Survey (HIPASS) to construct an HI mass function and derived a low mass slope of a 1.30. Using 265 galaxies from the Arecibo Dual-Beam Survey (ADBS) 10 find a low mass slope of a 1.53. The HI mass functions in both the Centaurus A and Sculptor groups are inconsistent with a slope steeper than a 1.5 11 . Recently 12 carried...

References

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Constraints on cosmological parameters 51 The temperature function

The X-ray Temperature Function (XTF) is defined as the number density of clusters with given temperature, n(T). As long as a one-to-one relation exist between temperature and mass, the XTF can be related to the mass function, n(M), by the relation In this equation, the ratio dM dT is provided by the relation between ICM temperature and cluster mass. Measurements of cluster temperatures for flux-limited samples of nearby clusters were first made by Henry & Arnaud 28 . These results have been...

Galaxy flows around groups and clusters

The large-scale velocity field provides a significant source of information on the distribution of mass fluctuations in the Universe. Moreover, the relation between peculiar velocities and mass is simple, providing a direct indication of the distribution of mass independent of assumptions about the bias factor of different galaxy types. Here we summarise the simulation results on infall of dark-matter particles towards massive haloes we presented in 6 . Our main results, shown in Figure 3,...

Forming intracluster light

The classic picture for the formation of intracluster light is through tidal stripping of galaxies orbiting within the potential well of a massive cluster. While this mechanism is undoubtedly at play, the hierarchical nature of cluster accretion means that other dynamical processes must contribute as well to the formation of ICL. Clusters grow not simply through the slow one-by-one addition of galaxies, but through the accretion and coalescence of smaller galaxy groups. These groups have a...

Highlights of GEMS results

Various GEMS results are presented by Ponman, Kilborn, Brough and Ray-chaudhury at this meeting. Here I briefly mention some other results. Our Parkes telescope HI mapping covered 5.5 sq. degrees of 16 southern groups 4 . We sample out to radii of a few Mpc or several virial radii. The Fig. 1. NGC 5044 group showing HI detections as a grey scale contours previously catalogued group members as crosses from 4 . The large circle shows the r500 radius. The Parkes beam size is shown lower left. NGC...