Institute for Advanced Study Informal Astrophysics Seminar

The Lyman alpha forest, DLAs and metal absorbers are tracers of the large-scale structure with different linear bias factors, which can be measured and compared to model predictions. The large number of quasar spectra in the BOSS survey allowed for the first measurements of auto and cross-correlations among these tracers, with powerful implications for our understanding of the intergalactic medium and galaxy formation. The measured bias factor of DLAs show that DLAs with strong metal lines are hosted by massive halos associated with massive galaxies and galaxy groups, while DLAs with weak metal lines are associated with dwarf galaxies. The Lya forest bias factors are a test of our basic ideas on the gravitational evolution of a photoionized intergalactic medium.