Observational studies on high-redshift quasars

Abstract

The discovery of high-redshift quasars with redshift higher than 6, which exist when the Universe was only 1 billion years after the Big Bang, provides important probes to help us study the early Universe. This makes the observational study of high-redshift quasars becoming a hot topic in the research frontiers of galaxies and cosmology. In this review, we stress the importance and cosmological implications of observational study of high-redshift quasars, introduce our recent discovery of an ultra-luminous quasar with a 12 billion solar mass black hole at redshift 6.3, and summarize the observational results on the host galaxies of high-redshift quasars. In addition, we present our perspectives on the future study and the challenges in this field.