New Perspectives On Galaxy Evolution From the COSMOS Survey

Peter Capak


The 2 square degree COSMOS HST field has become one of the best for studying galaxy formation and evolution. At redshifts greater than 1 COSMOS probes a volume similar to the SDSS in the local universe with similar sensitivity and resolution.  It has deep coverage from  Chandra, XMM, Galex, Hubble, and Spitzer along with extensive ground based observations from the UV to the radio and over 30,000 spectra from VLT, Keck, and Magellan.  This superb data allows for photometric redshifts accurate to dz/(1+z)=0.01 for both galaxies and AGN at i<24, allowing for large statistical studies of galaxy evolution.  The majority of this data has been or will be released to the public in the next three months.

This talk will focus on new insights on galaxy formation and evolution from these data.   This cosmologically significant volume provides strong constraints on the formation of massive galaxies.   I will show several bright z~7 galaxy candidates selected as dropouts from deep infrared imaging, a gas rich major merger at z=4.547 forming stars at over 2000 solar masses per year, and the evolution of the UV luminosity function between 4<z<7.  How these results change our view of galaxy formation in the early universe will be discussed.  At redshifts less than 2 I will show constraints on the buildup of mass in early type galaxies based on their mass function, morphological evolution, and clustering properties.