Searching for Extended Ly-alpha around High Redshift Quasars

High redshift quasars are essential to understanding the formation and growth of supermassive black holes (SMBHs) in the early Universe. Multi-wavelength observations of quasars at z > 6 yield SMBH mass estimates on the order of billions of solar masses, and star formation rate estimates on the order of hundreds of solar masses per year. Such high SMBH masses imply that the earliest black holes must grow rapidly such that billion-solar-mass SMBHs exist within a billion years of the Big Bang.

Rapid star formation and SMBH growth consumes the large fuel supply of cool gas available in the circumgalactic medium (CGM). Radiation from the quasar is reprocessed by the CGM gas, and shines as an extended Ly-alpha halo. Observing this halo provides important diagnostics of the spatial distribution and kinematics of the gas that fuels the rapid SMBH growth and star formation.

In this project, we utilize the capabilities of the Keck Cosmic Web Imager’s (KCWI) red channel to search for extended Ly-alpha emission around z > 6.5 quasars, including targets selected from the JWST ASPIRE sample.