case western reserve university



Galaxy And Mass Assembly: a survey probing fundamental Cold Dark Matter model predictions

Peder Norberg (Institute for Astronomy, University of Edinburgh)

The 2 degree Field Galaxy Redshift Survey (2dFGRS) and the Sloan Digital Sky Survey (SDSS) have transformed our view of large scale structure in the low redshift Universe, reinforcing our standard cosmological model: a flat, dark energy dominated collisionless Cold Dark Matter model (\LamdbaCDM). However, neither survey is able to put stringent constraint on a key CDM model prediction, i.e. the shape of the dark matter halo mass function, a crucial component to all hierarchical galaxy formation models.

Therefore, we designed the Galaxy And Mass Assembly (GAMA) survey with primary aim to accurately determine the CDM halo mass function over a large mass range. This deep (ten times fainter than SDSS) and wide (~250 sq.deg.) galaxy redshift survey samples the underlying large scale structure with unprecedented detail. In particular, the key scale over which the baryons and baryon physics become critical to our understanding of the structures we see, ie. the 1 kpc to 1 Mpc range, is the one that GAMA probes to an exquiste level.

Started in March 08 using AAOmega on the AAT, GAMA has acquired already more than 95k good quality spectra of galaxies, typically ten times fainter than those targeted by SDSS or 2dFGRS. In this talk, I will first overview some of the main results from SDSS & 2dFGRS, emphasizing on both their successes and limitations. This will indirectly lead me towards an outline of the main GAMA science goals, and present some preliminary science results from this unique dataset.

If time allows for it, I will finish with a small digression about the upcoming Pan-STARRS project and my direct involvement in the large-scale structure studies using the 3PI and median-deep field surveys.