Speaker
Description
Simulations and theory struggle to explain the existence of supermassive black holes at z>6, i.e. after less than 1 Gyr after the Big Bang, but all models expect that they formed in the most massive haloes of the early Universe. A direct and testable consequence is that z>6 quasars should be surrounded by overdensities of galaxies extending up to 8 Mpc, but observational studies returned inconsistent results. This is possibly due to the limited FoVs of the instruments often used, that do not trace such spatial scales. In fact, the few studies that employ wide FoV imagers, such as LBT-LBC, always detect significant galaxy overdensities around high-redshift QSOs, but the interpretation of these results is limited by the small number of covered QSO fields. SQUEEzE is an ongoing INAF LBT Strategic Program that collected optical (LBT-LBC) and IR (CFHT-WIRCAM) multi-band photometry of the fields of ~15 quasar at z~6 to identify high-redshift Lyman-break galaxies and perform the first statistical study of the z~6 quasar environment up to 8 Mpc scales. The targeted quasars span wide ranges of BH mass, luminosity, and radio loudness, allowing us to investigate secondary trends of the environment with such quantities. In this talk, I will present the program and show the first results on a subsample of fields.
| Collaborators (if any) | Fabio Vito, Marco Mignoli |
|---|