SEARCHING FOR QUASAR FEEDBACK IN OBSCURED AND RED QUASARS AT THE PEAK OF GALAXY FORMATION

[摘要] Though small on the scale of their host galaxy, supermassive black holes likely play a crucial role in galaxy evolution. A galaxy-scale effect driven by supermassive black holes (or ``quasar feedback”) is necessary to stop the production of too many massive galaxies in semi-analytical simulations and to drive observational correlations between host galaxy and black hole properties.Nevertheless, such a mechanism is not yet well supported by observational evidence, especially at the peak of galaxy formation. This thesis represents an effort to ground every aspect of quasar feedback at the peak of galaxy formation with strong observational evidence. I first define a sample of obscured and actively accreting supermassive black holes (``quasars”) at the peak of galaxy formation using the Sloan Digital Sky Survey. Then, using targeted observations of small sub-samples of these objects across a variety of wavelengths, I show that in a sample of the most luminous quasars, we see emerging evidence for quasar feedback.I show that luminous quasars are capable of launching winds by studying their scattering geometry and kinematics using spectropolarimetry. I advance the theory that sensitive, high resolution radio observations allow us to search for the presence of such winds on galaxy scales. Finally, I show that these winds go on to clear their host galaxies of the molecular gas necessary for star formation. All together, this body of work provides a robust observational window into important mechanisms of galaxy growth and quenching at the peak of galaxy formation and evolution.

[发布机构] Johns Hopkins University

[效力级别] Astrophysics

[关键词] Astronomy;Astrophysics;Observation;Active Galactic Nuclei;Physics