Forth submission. 384242591 Assigned ID: 4639 ----- Attempting Submission 1 (Wed May 24 20:53:35 GMT 2023) ----- HST Phase I Proposal 4639 successfully submitted. Receipt: # 4639-1 ----- Attempting Submission 2 (Wed May 24 22:43:35 GMT 2023) ----- HST Phase I Proposal 4639 successfully submitted. Receipt: # 4639-2 ----- Attempting Submission 3 (Wed May 24 23:51:04 GMT 2023) ----- HST Phase I Proposal 4639 successfully submitted. Receipt: # 4639-3 ----- Attempting Submission 4 (Wed May 24 23:56:47 GMT 2023) ----- Recent JWST observations show that frequent AGN activities among high-redshift galaxies, further suggest strong connection between supermassive black hole (SMBH) growth and galaxy formation in the early universe. However, AGN selections in current deep surveys are highly incomplete due to both flux limit and color selection effects. Variability is an ubiquitous signature of AGN activity and has shown to be a powerful tool in AGN discovery acrros all redshift and luminosity. We propose to conduct a HST archival program to search for variable sources in deep field areas that have been observed in near-IR wavelengths with both HST and JWST Cycle-1 observations. These observations, covering a total area of 2500 squared degree, will sample the rest-frame UV wavelengths with an average time lag of seven years beteween HST and JWST observations, ideal for AGN variability search. We will search for variable sources using a combination of PSF matched photometry, SED fitting and imaging subtraction techniques. This archival program will focus on low-luminosity AGN in high-redshift galaxies, and we expect to find ~200 faint variable AGNs (m<27) at z=5-7 with high completeness. This will be the first variability selected faint high-redshift AGN sample. It will provide independent measurements of the faint end of AGN luminosity function, characterize the evolution of SMBH accretion activities by studying redshift dependence of variability, and uncover the relationship between AGN activities and their host galaxies in the early Universe. Mr. Wei Leong Tee is conducting research in finding faint and high redshift quasars and AGNs to understand the origin and growth of supermassive black hole. Prof. Xiaohui Fan and Prof. Feige Wang are leading experts in many HST and JWST program, specialized in observational high redshift quasar study, characterizing supermassive black hole properties, the environment they reside in and their interaction with host galaxies. Supermassive Black Holes and Active Galaxies 0 Regular false false false false false false SUPPORTED