previewThis project aims to solve the following key problems: (1) How to obtain highly accurate measurement of black hole masses, and then get the mass function and accretion rate function of black holes to determine their evolution laws? (2) How the coevolution of supermassive black holes and their host galaxies changes through cosmic time? How to organize star formation in galaxies? What is the mechanism of the coevolution? (3) How to improve the efficiency of selection of high-redshift quasars? What is the difference between quasars in early and local universe? Is there a upper limit of black hole mass? What is the formation mechanism of extremely supermassive black holes (more than ten billion solar masses)? What are their cosmological effects? (4) Is there physical connection between black hole accretion and broad-line region? Is there feedback from outflow to galaxies? Is there relationship between binary black holes, the evolution in the nuclear regions and their host galaxies? What is observational characteristics of supermassive binary black holes as sources of gravitational waves? Answering these questions would demonstrate an overall picture of the coevolution of supermassive black holes and their host galaxies, and reveal the underlying physical processes. This requires measuring the following several main parameters: (1) the masses of black holes with different accretion rates at different redshifts, (2) the masses of stars and gases in galaxies, (3) the spectral energy distribution of AGNs, (4) the profiles of galaxies and the observational features of feedback.

This project contains four groups, each one focuses on one of the following topics: 1.  Measurement of black hole mass. The spectroscopically monitoring and multi- wavelength observations are carried out for AGNs and quasars of different types to measure the masses and accretion rates of their central black holes accurately, to establish the scaling relation of broad-line region, and then to measure the black hole masses and accretion rates in large samples in order to study their evolutionary rules. 2. The coevolution of supermassive black holes and their host galaxies. It aims to measure the masses of stars and gases in galaxies, to obtain the coevolution in galaxies of different types, and to study the relation of the triggering of black holes with star formations, and then to discuss their cosmological evolution. 3. High-redshift quasars and the reionization  of the universe. This group aims to develop new methods of highly efficient target selection. By making use of optical-infrared observations, we hope to find quasars in high redshift, and to determine luminosity function and its effects to the reionization, and then to research the mechanisms of formation and growth of black holes. 4. The physics of central engine. It includes the dynamics of accretion and outflow (wind and jet), the interaction of radiation and outflow with the interstellar medium in host galaxies, their influence to galaxy evolution, the feeding of black holes and so on. It also aims to study the evidence of supermassive binary black holes, and to find the sources of gravitational waves. Finally, we hope to exhibit a complete story of the coevolution.