Special Astrophysics Seminar

The galaxy-halo connection at z=1.6

Jesus Martinez

University of Florida

Under the Cold-Dark-Matter scenario, galaxies must form inside dark matter haloes. A fairly good description of their connection up to intermediate redshifts has been developed during the last decade, thanks to the advent of large redshift surveys. These revealed that during 0<z<1, most massive galaxies are already in place and the star formation shifts to smaller haloes. Yet, it is still not totally clear what halo-driven mechanism is responsible for quenching star formation at high masses. At z>1, this picture becomes more uncertain, and studies providing strong constraints are scarce. Moreover, the z>1 epoch is of great importance, since it is when most of the galaxy mass is assembled and therefore where the evolving influence from the halo could be more evident. In this talk, I will be presenting preliminary results on the galaxy-halo connection at z=1.6, which are some of the most robust to date around this redshift. We use data from the SSDF, a new 100 sq. deg. Spitzer survey in in the [3.6] and [4.5μm] bands. Even though optical data is not available, applying simple color and flux limits allows us to select galaxies in stellar mass and redshift. We fit halo occupation distributions to the galaxy clustering and are able to fully map the relation between stellar and halo masses across the relevant range of the mass function.