Evidence for Gas Accretion into Distant Massive Galaxies from the GOODS NICMOS Survey

Abstract

We discuss a full analysis of the modes of galaxy formation for massive galaxies with log M > 11 at z < 3 based on data from the Hubble GOODS NICMOS Survey. I will discuss the role of major mergers, star formation, and for the first time, minor mergers, in the formation of massive galaxies from z=3 until today. This is possible due to using new near-infrared Hubble Space Telescope imaging from NICMOS focused on massive galaxies in the distant universe. I will further show that modes besides the above are needed to form galaxies and will argue that gas accretion from the intergalactic medium is an important method for adding mass to these massive galaxies, and potentially a major new part of the galaxy formation process.